ELECTRICITY AND ELECTRONICS

ELECTRICITY AND ELECTRONICS
CHAPTER 5
ELECTRICITY AND ELECTRONICS
more complicated problems of adjustment,
alignment, and troubleshooting of electrical and
The preceding course and the basic courses, electronic equipment.
Basic Electricity, NAVTRA 10086 and Basic
Electronics, NAVTRA 10087, have discussed the GMM AND ELECTRIC AND ELECTRONIC
principles of electricity and electronics and
PARTS
explained how they apply to missile launching
systems. The extensive application of electricity
All the electrical and electronic components
and electronics in missile systems make used to operate and test the launching system are
understanding of the principles and their part of the GMM's responsibility. While this is no
applications a necessity for the GMM. Practically small assignment, it does leave out (for other
every part of a weapon system is operated or ratings to operate and service) a complicated
activated by electrical and electronic parts. The ET, assortment of equipment, such as radars and radar
FT, and other ratings are responsible for the care test sets, computers, weapon direction equipment,
and maintenance of some parts of the weapon target detection equipment, and target tracking and
system, but there are numerous electric and missile tracking apparatus.
electronic parts in the launching system whose
A review of the quals (Electricity and
maintenance is your responsibility.
Electronics) show that nearly all the knowledge
A typical firing circuit and a power control : factors in these fields are required of the GMM 3
circuit were described and illustrated in the and 2. In the practical factors, the GMM 1 and C
preceding course. We explained the action of each are expected to do the troubleshooting, casualty
component, so that you could trace the functioning analysis, overhaul, repair, and adjustment on
on the drawings. Troubleshooting techniques as electrical and electronic components of the
applied to circuits were explained and launching system. You have learned to use the test
troubleshooting charts were presented. You were instruments for simple maintenance and repairs.
instructed in the use of various meters in testing Now you must learn to use the most sophisticated
and
measuring
electrical
and
electronic testers, and to locate electrical and electronic
components. Now you should be able to teach troubles and correct them. This is practical
others how to use those meters and testers. If there application of the principles you have learned.
are some weak or fuzzy areas in your knowledge,
go back and review. You cannot build advanced CONTROL
PANELS
IN
LAUNCHER
knowledge on a weak foundation.
SYSTEMS
This chapter will tell you more about
applications
of electrical
and
electronic
Table 3-1, in chapter 3, lists the control panels
components in the operation of missile systems to by Mk and Mod numbers for all the missile
help you see how the principles are applied to these launching systems currently used. As development
components. From these you should advance to the of launching systems has advanced
INTRODUCTION
115
GUNNERS MATE M 1 & C
from experimental stages, standardization has
increased. This not only reduces production and
maintenance costs, but simplifies training of
personnel. There are still many differences in the
control panels for the different systems,. and there
always will be some, but the similarities are
greater. However, it is still far from "if you know
one you know them all." Review chapter 3.
Similarities and differences in the missile
launching systems were discussed in that chapter.
CONTROL PANELS OUTSIDE THE
LAUNCHER SYSTEM
It is impossible to describe the operation of the
launcher control panels without constant
reference to the control panels in the weapons
control station, CIC, and controls on the bridge.
There is a constant flow of information and
direction to and from the various components of
the weapon system. (See fig. 3-1 in chapter 3.)
Figure 5-1 shows typical location of component
of a weapons system. Communication between
components must keep open. In addition to
indicating
lights
on
panels,
telephone
communication between stations is used to relay
report or orders. An alternate system must be
ready to take over in the event of failure or
destruction of the other.
Many of the circuits in the launcher power
panels are activated from control panels outside
of the launching system. They are tested in
cooperation with the operator of the panel
sending the activating signals. When there is any
failure, the GMM checks out the connection to
his panel and works with the other operator to
check out the whole circuit.
Training and elevation power drives are
controlled by orders from the director, relayed
through the launcher captain's control panel. Load
orders and firing orders are transmitted to the
launchers through the weapons control station
and the launcher control panel. There may be a
breakdown anywhere along the system and the
GMM must help to find the trouble and correct it.
CIRCUIT TESTING BY THE GMM
The preceding course, Gunner's Mate M
(Missiles) 3&2, NAVTRA 10199 contains a
chapter on use of meters for testing, making
electrical measurements, and troubleshooting
circuits. Review any parts about which you are not
clear. A solid understanding of the underlying
principles is necessary before trying to understand
complicated variations.
NOTE: The routine testing of ship's weapons
control circuit wiring makes use of 500-to 1000volt meggers. These checks are performed
periodically as a regular part of preventive
maintenance procedures. Repeated high potential
tests (over 300 volts peak) can damage synchros
and other small rotating components. High
potential tests involving these components should
be limited to those required for qualification and
acceptance at the time of manufacture. Synchros,
servomotors, resolvers, tach-generators, etc.,
should be disconnected from the circuit when
megger or ground tests are being conducted.
Missile system installations greatly increased the
requirement for 400-hertz power supplies having
varying degrees of voltage and frequency
regulation. Missile ships have had, to install 400hertz generating plants to satisfy the demand. All
missile ships have three separate 400-hertz power
systems, each consisting of two or more motor
generators. One is used for the ship's service
system; another supplies the continuous wave
illuminators used with guidance radars, and the
third the most closely regulated (voltage and
frequency) 400-hertz system, is used on ships for
missile systems.
Launcher electric motors are started and run
under the power of a 440-volt 60-hertz ship's
power supply. The slipring assembly, on the
launcher stand and carriage, provides continuous
interconnection between on-launcher and offlauncher electrical connections while allowing
unlimited train motion of the launcher. Qn the
Talos launcher, the slipring (fig. 5-2) consists
basically of a 440-volt collector ring assembly, a
115-volt collector ring assembly, and a fluid
slipjoint. Each collector ring assembly has a
rotating and a nonrotating section (fig. 5-3). The
rotating sections mount collector brushes that are
connected by cabling to circuits of on-launcher
equipment. The nonrotating sections mount
collector rings which are connected by cabling to
the circuits of the off-launcher power and control
components. The rings are engaged
116
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
by the brushes of the rotating sections to complete
the electrical circuits. The four brushes contained
in each brush ring are electrically connected to a
terminal on the outer surface of the ring (fig. 5-3).
The launcher cabling connects to the terminals of
the assembled brush rings.
Close voltage and frequency regulation are
necessary for use in the missile system. Voltage
and frequency regulated equipment can now be
provided in 30-, 60-, 100-, 200-, and 300-kw sizes,
with voltage balance regulators supplied when
necessary. Supplying the power needed for the
missile system is in the province of the ship's
engineering department.
While depending on the engineering department
to supply the power in the voltage and frequency
desired, you have tested circuits and tubes and have
used schematic diagrams, block diagrams, voltage
and resistance charts, and troubleshooting charts.
Experience and study will help you improve your
ability to interpret
the results of the tests and trace a malfunction. It is
possible to track down a malfunction by checking
each part or component in the circuit-following the
circuit diagram until you come to the defective
part. But that may take hours of tedious work. A
study of the problem may reveal a shortcut that will
locate the trouble in much less time. While there is
much to be said for patient, dogged, stick-to-itiveness in a troubleshooting job, the application of
brainpower to locate the trouble in short order is
more commendable. You cannot do this with much
success, however, if your knowledge of your
weapon system is superficial.
Troubleshooting Control Panel Circuits
With the enormous amount of wiring and
electrical components required in a weapons
system, it is not surprising that a high proportion of
the failures are in the electrical system.
117
GUNNERS MATE M 1 & C
The control and power relays of the Mk 10 Terrier
launching system, for example, consist of more
than 400 miniature rotary relays, 6 subminiature
relays, 46 medium-size rotary relays, and 6 smallsize rotary relays. These relays are in the EP1, EP2,
EP4, and EP5 panels.
Conscientious application of the 3-M system is
intended to reduce the incidence of failure. The
MRCs give step-by-step detail of what to do for
routine maintenance, but when any part of
the equipment fails to perform as it should, you
have to turn to the OPs for aid in troubleshooting.
The OP also gives the frequency of tests, checks,
inspections, and servicing of the different
components. If the OP differs from the MRC in
this, follow the MRC instructions.
Let's concentrate on the EP I panel, which is the
basic distribution panel for all electrical power to
the launching system. It contains switches, circuit
breakers, fuses, relays, and
118
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
contactors for the power and control circuits. The
launcher captain turns on the various circuits
before he goes to the EP2 or launcher captain's
panel, which he mans during operations. In figure
5-4 the items are identified by number. Lights in
section no. I indicate that the 440-volt power has
been turned on and is available on the panel. As the
motors in the launching system are energized,
lights in section 2 come on: (a) B-side magazine
motor; (b) Train motor; (c) Elevation motor; and
(d) A-side magazine motor. The circuit breakers
for these motors are in section 3. Lights in section
4 indicate that the following motors are energized:
(a) B-Side loader motor; (b) Launcher rails motor;
(c) Circulating system motor; and (d) A-side loader
motor. Section 5 has the circuit breakers for these
motors. The two lights in section 6 are for A and
B-side loader accumulator motors, and the circuit
breakers for these are in section 7, with a third
circuit breaker for the control system. When you
activate the panel, you turn on all these switches
and circuit breakers unless only one side of the
launcher is to be used, and then you turn on only
the circuit breakers and switches for that side.
119
GUNNERS MATE M 1 & C
120
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
Lights in section 11 indicate that power is
available for the 120-volt warmup circuits and the
light in section 13 indicates power available in the
115-volt control circuits. The On-Off switches for
warmup supply circuits and control supply circuits
are in section 14 and the fuses are in section 15.
Each fuze block has two fuses and two fuse-blown
indicating lights. Two extra fuses are in section 16,
with screw-on watertight caps.
If light No. 8 is on, it indicates that the door
interlock on the panel is inoperative. A magnetic
latch on the door prevents opening it while the
power is on. Before the door can be opened to ,
make repairs, etc., the 440-volt power must be
turned off and then the door handle (no. 9) can be
turned to open the door. No. 10 is an emergency
release for the magnetic door latch. No. 12 is a
ground detection indicator. It monitors the 117-volt
control supply circuits and triggers an alarm if
there is a grounded circuit. Figure 5-5 shows in
outline the EP1 functions.
PRELIMINARY ISOLATION. - Let's assume that
you have turned on all the switches and circuit
breakers on the EP1 panel to activate the system.
You notice that a fuse-blown light for switch d in
section 14 is on. This means that control supply
circuit No. 3 for the B-side feeder is disabled in
some way. You have to find where the trouble is.
Check the fuse blown light first. You will need to
look inside the panel. Before
you can do that, you must disconnect the power
supply; the panel door will not open while the
power is on. Besides, you may not work on
energized electrical equipment without an express
order from the ship's commanding officer:
Remember safety rules for working with electrical
equipment: were no rings, wristwatches, bracelets,
or similar metal objects. Do not work with wet
hands or wet clothing Wear no loose or flapping
clothing. Discharge any capacitors before touching
them - they retain a charge after they are
disconnected from their power source.
You may see; the cause of the failure as soon as
you look behind the panel door, but more than
likely you will need to get the electrical drawings
and trace the wiring until you find the trouble. The
power distribution cables are numbered 0 to 99,
and the wires are numbered 0 to 999. Loading
control cables for the "A" side are numbered 200 to
299, and for the "B" side the numbers are 300 to
399. Wire and cable numbers are assigned in
groups, with "A" or "B" added to indicate the side
served by the wire or cable. For example,
"WSA2022" means "Wire, single conductor, no.
2022 of the A-side loaded circuitry." The cabling
schematic also identifies the type and size of wire
used in each application. The drawing explains the
component type designations used, such as "WS"
above, and the major assembly designations, such
as "LB" for Loader, B-side, or "BA" for dud
jettison, A side. All electrical and hydraulic
121
GUNNERS MATE M 1 & C
components are identified by a combination of
letters and numbers that indicate the kind of device
or component, the identification of the major
assembly of which it is a part, and identification of
the specific component. These reference
designations do not replace drawing, part, or stock
numbers. They identify the part on the schematic.
For example, KCLA1-1AB can be interpreted as
follows:
KC-relay, control
LA-Loader, A side
1 - No. 1 among the relays associated with the
A-side of the loader.
lAB-the A and B contacts on the first wafer or
section of the relay. It also indicates that the A and
B contacts on the first section of the relay are wired
in that circuit application.
To return to the EP-1 panel and your problem. If
the trouble is only a faulty fuse, replace it.
However, remove and replace fuses only when the
associated circuit is completely deenergized. Use a
fuse puller made of insulating material. Use a fuse
of the same rated voltage and amperage capacity.
Never short a fuse. After you have replaced the
fuse, replace the fuse cover (if it has one), then
energize the circuit. A fuse may explode when the
circuit is energized.
When you have located the trouble that caused
the fuse to blow, and have repaired it, reactivate the
panel to check the work you have done.
Since the EP1 panel is connected directly to the
ship's electrical system for its power supply, you
need to work with the ship's electricians when there
is a failure in any of the lines connected to the
ship's power supply.
CIRCUIT TROUBLE AT THE EP2 PANEL.Assume that you have turned on all the connections
at the EP1 panel and power is available for all the
circuits. You are now ready to take your position at
the EP2 panel. You receive orders from Weapons
Control regarding the mode of operation, the type
of missiles to be used, single loading or continuous
loading, and whether A-side or B-side or both are
to be used. You are ready to activate the EP2 panel,
through which electrical power is supplied to the
different units of the launching system.
The magazine, which consists of the ready service
ring, the load status recorder, the hoist mechanism,
and the magazine doors, is operated by hydraulic
power from Power Drive Mk 64. One power drive is
located on the A side and the other on the B side.
Individual controls for the units are on the EP2
panel. Circuit No. 2 for control supply furnishes the
l17-volt a-c electricity to operate the motor that
drives the pump to develop accumulator pressure.
The start circuit for the magazine accumulator motor
is controlled from the EP2 panel. When the contactor
(KPXA1 in fig. 5-6) is energized, it closes contacts
which complete the 440-volt supply to the magazine
accumulator motor (BPXA1 ).
Normally there will be no trouble starting the
magazine accumulator motor by depressing the
START-RUN pushbutton switch SMXA16A (fig. 56). However, a malfunction may occur at any time in
such a complex equipment. It is important, therefore,
to understand the motor start circuit and the relay
elements it includes.
To complete the Start circuit, you position SMS1
(Control Selector Switch) at STEP, SMS2
(Operations Selector Switch) at OFF, and SMX3 (Aor B-Side Selector Switch) at A or A AND B for Aside operation, or B or A AND B for B-side
operation. Control Selector Switch SMS1 must be
positioned at STEP during activation in order to start
the motors, and switch SMS 2 must be at OFF
during that time to prevent system operation until
activation is completed.
With these manual switches positioned, it is time
to position the switches or relays for the ,
components powered by the accumulator unit. The
positioning
latches,
both
clockwise
and
counterclockwise, for the ready service ring must be
extended so the ready service ring will not start
indexing before the system is ready. Both tray shift
solenoids (LHDAl-LCl and LHDAl-LC2) must be
deenergized and the associated solenoid rocker arm
must be at neutral to prevent indexing ahead of
readiness. The normally closed (N.C.) contacts of
these switches are wired into the Start circuit, so the
switch elements are closed when not actuated. Hoist
solenoid switches (LHHAl-SIl0l and LHHAl-SIl02)
and magazine door solenoid switches (LHGAlSI101 and LHGAl-SIl02) perform the same function
- prevent premature activation of the associated parts
of the launching system.
122
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
123
GUNNERS MATE M 1 & C
Relay elements KCHA1 and KCHA2 keep the
hoist in either the latched up or latched down
position so it will not be stopped in midcycle. The
magazine door solenoid switches (LHGA1-SI101
and LHGA1-SI102) remain deenergized at this
time so the doors will not open. Both overload
relay elements (KPXA2) and (KPXA3) are closed
because there is no overload in the 440-volt power
supply to magazine motor BPXA1. The remaining
elements between SMXA16A and the KPXA1 coil
remain closed during the motor-state procedure.
The Magazine Motor STOP switch (SMXA17) is
spring-held in the closed position unless it is
depressed to stop the motor. Also closed is
LHXA1-SI101, the solenoid switch to dump
magazine accumulator pressure if it becomes
necessary. The solenoid LCI will not energize until
the motor has been stopped.
Now, with all the manual switches properly
positioned and the associated interlocks closed, you
are ready to press the Magazine-Motor STARTRUN button, SMXA16. This completes the l17volt circuit to the coil of the motor contactor
KPXA1.
When the contactor coil is energized, it closes
contacts A, B, and C of relay KPXA1 in the 440volt motor power circuit and contact D in the motor
run circuit. The motor should start and begin
driving the parallel piston pump.
Suppose the motor doesn't run after you have
pressed the start button. Maybe somebody forget to
push Magazine Safety Switch to RUN (SMZA12),
a manual switch on the EP4 panel which must be
positioned to RUN. If that is not the cause of the
nonoperation, you will need to get the drawings for
the system to trace down the cause of the failure.
The schematic helps you picture the layout of the
system, but you will need the electrical diagrams to
make the proper corrections. Review the check list
to make sure you did not omit any step in the
activation. The checklists posted at the panel
should be used every time the panel is activated.
COMPONENT ISOLATION. - Once the source
of trouble has been isolated to a particular circuit,
several aids and short-cuts are available for
isolating the defective component. Three probable
sources of trouble in circuits are: an open relay
coil, an open diode, or a shorted
diode. When isolating troubles, first determine
which coils of the relays are energized when a
pushbutton is pressed. The drawing or the
maintenance manual may have a listing of the coils
of the relays for each circuit. Check each circuit
systematically for opens, and for shorts. There is
little likelihood of a shorted relay coil, but a diode
wired across the coil of the relay may be shorted,
and that would cause a fuse to blow as soon as the
circuit to the relay is completed. Shorted diodes in
other circuits may cause no such giveaway reaction
but may permit current to pass through other
diodes. Those are more difficult to locate. When
the shorted diode is isolated from the associated
circuitry, do not assume it is bad; its forward and
backward resistance should be checked.
CHECKING RELAYS. - Relays suspected of
faulty action may be checked with the relay test
equipment mounted on the inner side of the EP2
panel front door (fig. 5-7), next to the door latch.
Before testing relays, the pins should be examined
to be sure that they are not bent. To straighten bent
pins, firmly seat the relay in the pin straightener
mounted in the top of the test panel (fig. 5-7).
Terminal pins on a plug-in type of relay are shown
in figure 5-8B. After any necessary straightening,
insert the terminal pins into the test socket (fig. 57). The toggle switch SMZl9 applies (or removes)
power to the coil of the relay being tested. SMZl9
also switches the circuitry of the test socket to
permit testing of the normally open or normally
closed internal circuits of the relay as desired.
Selector switch SMZl8 permits checking the
individual internal circuits of the relay, normally
on or normally closed, as determined by the
position of SMZI9. As each internal circuit of the
relay is tested by positioning SMZI8, indicator
light DSZl3 indicates whether the relay is operating
properly.
INTERLOCK SWITCHES. - The switches on
the control panels are chiefly manual switches of
pushbutton, rotary, or toggle types. Numerous
interlock switches are used throughout the
launching system. They are actuated by mechanical
motion or hydraulic pressure, and are used to
monitor equipment functions. The design varies
with the application, but usually consists of one or
more switch elements
124
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
mounted to an actuating device. They assume that
related equipment is at a certain position or has
performed a certain function, so that operation will
be in sequence. For example, the hoist cannot raise
a missile to the loader if the magazine doors are
closed. The circuit energizing the solenoid which
controls hoist raise operation contains an interlock
that does not allow circuit completion until the
magazine doors are open and secured. This
interlock is a relay wired into the solenoid circuit.
When the relay is energized the interlock is closed.
The relay energizes when the associated interlock
switch, mounted to the magazine door equipment,
is actuated. This switch actuates when the
magazine doors have fully opened and the door
lock latch is engaged. Other interlock switches in
the circuit assure
that the loader is in position (retracted) above the
magazine doors and that the tray shift on the ready
service ring is positioned to hoist. Even the motor
start circuit includes interlocks. They assure that
powered equipment is not halted in midcycle.
When interlock switches malfunction, the entire
switch assembly is removed and a replacement unit
is installed. Before the replacement unit is
installed, it should be checked electrically with the
switch test device (special tool 1614018) to be sure
that it functions properly.
The interlock switches of the Mk 10 Mod 0
launching system control are of two types. The
majority of the switches are sensitive switch
assemblies, and the rest are microswitches mounted
in the solenoid housings and in the load status
recorder assembly. The OP for the system has a
listing of all the sensitive switches, the location of
each, its function, the reference drawings, and
instructions for adjustment, with an additional
listing of solenoid, interlock switches mounted on
brackets and secured to the supporting frames of
the primary solenoids in the switch housing (fig. 59). The assemblies are of right-hand and left-hand
configuration, so when you are replacing one, be
sure to get the correct one.
Before
disconnecting
any
switch
for
replacement, be sure to mark down or note the
connection of each lend so you can connect the
leads of the replacement in exactly the same way.
Use a soldering iron to remove the leads, and when
attaching the new leads, solder them in place, after
placing the switch assembly in position and
securing it lightly. Adjust the air gap (fig. 5-9) with
the solenoids deenergized, according to the
reference drawing for that switch. Tighten the
locknuts after making adjustments.
LOAD STATUS RECORDER. - We mention
the lead status recorder here as an example of a
complex electromechanical assembly (fig. 5-10).
One is located on each ready service ring, mounted
on the outboard side of the truss. Its two basic
sections are a relay board assembly and a switch
and cam actuator assembly. It monitors the missile
type and condition at all 20 stations in the ready
service ring and sends this information to the
control panels (EP2, and EP4 (5) in the form of
interlock switch and visual
125
GUNNERS MATE M 1 & C
light indications. The ring of lights on the EP2
panel shows what the recorder tells; it is in the
ready service ring at each station. Shipboard
correction or adjustment of the electrical
components should not be attempted; remove the
defective unit, such as a triple switch or single
switch element, return it for repair, and install a
new unit. If the load status recorder malfunctions
mechanically, order a replacement from the supply
system.
The proper operation of the load status recorder
can be checked during the daily exercise of the
launching system. Each time the ready service ring
is indexed to another station, notice if the lights
representing the stations in the ready service ring
rotate in the same direction and amount. If there
are empty trays or trays with dud missiles, the
EMPTY and DUD indications can be checked. The
checking must be done in Step operation, operating
from the EP2
126
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
panel. For unload assembly, unload launcher,
checkout, or strikedown, the EP4 (or EP5) panel
must be used to rotate the ready service ring. The
loading pattern was set into the load status recorder
at the time the missiles were loaded, and if the
recorder is operating properly, the lights on the
control panels should read back the same as the
loading pattern. The color of the light indicates the
type of tray or round. Three amber lights inside
each circle of lights (representing the ready service
rings) indicate the meaning of the lights in the
circular pattern as
DUD, EMPTY, or LOADED. If you push the DUD
button (of those three), the lights should go on for
all the trays that hold dud missiles. If you push the
EMPTY button, the lights representing trays that
are empty should come on. If you activate the
LOADED button, the lights for all the trays
containing missiles should come on, the color
indicating the type of missile in each. In each case,
the light indications should agree with the loading
pattern established at the time of loading, unless
the tray assignment has been changed, or the
missile has been unloaded.
127
GUNNERS MATE M 1 & C
SAFETY RULES
It is your duty as a supervising petty officer to
instruct and remind your men of the safety rules
and see that they obey them. The first class and
CPO should conduct lessons on safety. Chapter 12
contains safety rules for electricity and electronics,
as well as for other situations.
SERVOMECHANISMS
An apparatus that includes a servomotor (or
servo for short) is often called a servomechanism.
And what is a servomotor? It is a power-driven
mechanism, commonly an electric motor, which
supplements a primary control operated by a
comparatively feeble force. The primary control
many be a simple lever, an automatic device such
as a photoelectric cell or a meter for measuring
position, speed, voltage, etc., to whose variations
the motor responds, so that it is used as a
correctional or compensating device. A servo is a
control device, a power amplifier, and a closedloop system. Gunner's Mate M (Missiles) 3&2.
NAVTRA 10199 described and illustrated the
fundamentals of servomechanisms. They are used
m all the power drives, and the principles apply to
all of them - only the details of application vary in
the different launching systems. Servos may be
electrical, mechanical electronic, hydraulic, or
combinations of these, but all use the feedback
principle. One or more power amplifier are part of
any servosystem. There must be an input and an
output, and between these, an error detector and an
error reducer. Each of these essential components
may have many parts, so that even a simple
schematic may seem like a complicated maze.
Remembering the essential parts of a servo d the
direction of the signals are helpful in tracing
through the schematic.
use in the training and elevating system is one of
their most extensive applications. The receiverregulators are described in the next chapter. The
emphasis there is on the hydraulic of the system.
Following are some suggestions for troubleshooting the electrical parts. But first review the
four steps:
Step 1.-Observe the equipment's operation.
Step 2.-Make an internal visual check.
Step 3.-Localize the trouble to the faulty parts,
using meters, electrical prints, and maintenance
publications.
Step 4.-Replace or repair the defective part; test
the system's operation afterward.
Electrical Prints
Locating components and tracing circuits is
generally easier when using electrical prints than
working on the wiring itself. Tracing the mass of
wiring, terminal strips, and obscured test points is
virtually eliminated when using the prints. The
components are grouped in the prints in a more
orderly manner. There are several types of circuit
diagrams. Those most commonly found in your
OPs and MRCs are wiring diagrams.
These diagrams are especially helpful in
understanding the operation of the equipment.
They show the parts of the circuit and how they are
connected. They do not show how the parts look or
how they are constructed - the components are
illustrated by symbols.
SYMBOLS. - There are several publications
containing lists of symbols, and from past
experience you can probably identify many of
them. As a first class or chief you must enlarge
your knowledge in this field, beyond the basics
required for the third class.
For the most part symbols are standard, but there
are variations. For all their variations, symbols are
really simplified sketches of the devices they stand
Troubleshooting
for. If you are reasonably familiar with the devices
Since the launchers must be trained and elevated they represent, you should have little trouble
every day as part of routine training and identifying the symbols in the schematics. Unusual
maintenance, any defects or failures in the or special ones are explained on the drawing.
servomechanisms of those systems will be evident.
Servomechanisms are used in connection with so
STRAIGHT LINING.-As there are tricks in all
many parts of a missile launching system, no one trades, there is one in circuit tracing. It is called
application can be considered as typical. Their
"straight lining."
128
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
Wiring diagrams and schematics are often a
complicated maze of many circuits, accomplishing
many functions. You must acquire the ability to
disregard all circuits that are unnecessary to the
one you are attempting to trace. The resulting
circuit, depicted on one drawing, will show only
the circuits necessary for one particular function.
This important feature of circuit tracing is called
straight lining.
Faulty Switches
The preceding course, Gunner's Mate M
(Missiles) 3&2, NAVTRA 10199, traced for you a
typical power control circuit and a typical firing
circuit, and showed you how interlocking worked
in the circuits, and how parts of the circuit operated
in a definite sequence. When you are tracing a
circuit to locate a casualty, remember to include the
interlocking switches that can prevent activation
along any part of the circuit. If a faulty switch is
found, it should be replaced or adjusted. Be
absolutely certain that a switch is faulty before
replacing it. It may only need adjustment to operate
properly. If a switch is replaced, it must be adjusted
within the equipment. Adjustment of interlock
switches requires familiarity with the function of
the switch contacts in the associated control
circuits. Study the applicable schematic wiring
diagrams. The complete control circuit is shown in
the applicable elementary wiring diagrams for the
system control.
Interlock switches must be checked periodically
to be sure they are actuating and deactuating
properly. Check them electrically to make sure that
they are making and breaking as required. When an
interlock switch malfunctions because of
mechanical wear or damage, replace the entire
switch. The Mk 10 Mod 7 Terrier launching system
uses eight types of interlock switches: (1) sensitive
switch assembly, used throughout the system; (2)
microsensitive switch, two used in the EP1 panel;
(3) 2PB switch assembly, used within the loadercontrol cam housing; (4) type A rotary switch, used
in, the Asroc adapter rail; (5) single switch
assembly, used within the dud-jettison solenoid
housings and within the load status recorders; (6)
paired switch elements used within the solenoid
housing, loader-control cam housing, contactors,
and magnetic circuit breakers; (7) paired
switch-element assemblies, used throughout the
system in standard solenoid assemblies and in
loader-control solenoid assemblies; and (8) triple
switch-element assembly, used in the load status
recorder
The maintenance instructions for the different
switches usually are included in the OP with the
instructions for the component to which each is
attached or which it activates. The MRCs give the
most up-to-date routine maintenance instruetions
for each component. Pull the appropriate MRC
card for each day's maintenance work.
AMPLIFIERS
Amplification of signals is necessary in the
launching system and in the missiles, as well as in
the fire control system. In electronics and electrical
engineering, vacuum tube amplifiers, transistors,
and magnetic amplifiers are widely used. There are
many types and arrangements of these, but the
purpose of all is to increase the magnitude of a
quantity. Amplifiers associated with electric and
electronic components are arranged to reproduce in
their output circuits a voltage or current greater in
magnitude than that applied to their input circuits.
Electron tube amplifiers may be grounded-cathode,
grounded-grid, or grounded-plate (cathode
follower) type. There may be a chain of amplifiers,
called cascade or multistage amplifier.
The conventional electron tube amplifier is the
grounded-cathode type, which has the cathode at
ground potential at the operating frequency, and
the input applied between the control grid and
ground, and the output load connected between
plate and ground.
The grounded-grid amplifier is an electron-tube
circuit in which the control grid is at ground
potential at the operating frequency, with input
applied between cathode and ground, and output
load connected between plate and ground. The
grid-to-plate impedance of the tube is in parallel
with the load instead of acting as a feedback path.
A grounded plate amplifier has a large negative
feedback and is often used as an impedance
matching device. The plate is at ground potential at
the operating frequency, with input applied
between grid and ground, and output load
connected between cathode and ground.
129
GUNNERS MATE M 1 & C
MAGNETIC AMPLIFIERS
The magnetic amplifier is rapidly becoming an
important device in electrical and electronic
equipment. Amplifiers of type have many features
which are desirable in missile systems. The
advantages include (1) high efficiency (90%); (2)
reliability (long life, freedom from maintenance,
reduction of spare parts inventory); (3) ruggedness
(shock and vibration resistance, overload
capability, freedom from the effects of moisture);
(4) stability; and (5) no warmup time. The
magnetic amplifier has no moving parts and can be
hermetically sealed within a case similar to the
conventional dry type transformer.
The magnetic amplifier has a few disadvantages.
For example, it cannot handle low-level signals
(except for special applications); it is not useful at
high frequencies; it has a time delay associated
with magnetic effects; and the output waveform is
not an exact reproduction of the input waveform.
The term "amplification" in general refers to the
process of increasing the amplitude of the voltage,
current, or power.
The term "amplification factor" is the ratio of the
output to the input. The input is the signal that
controls the amount of available power delivered to
the output.
Until comparatively recent times, magnetic
control has had little application in missile
electronic equipment since existing units were slow
in response and were of excessive size and weight.
But with the development of new and improved
magnetic materials, there has been a parallel
development of magnetic circuits for tubeless
amplification; and many of these units are now
employed in automatic pilots, static a-c voltage
regulators, and in associated test equipment. .
Magnetic amplifiers are devices which control
the degree of magnetization in the core of a coil to
control the current and voltage at the load or
output. One of the oldest forms of magnetic
amplifiers, the SATURABLE REACTOR, contains
at least two coils wound ,on a common core made
of magnetic material. A d-c control voltage is
applied to one of the coils; and the resulting current
serves to modify the reactance of the second
winding by causing magnetic saturation
of the common core. The second coil is a series
element in the a-c load circuit so that current.
variations take place in the load in accordance with
those made in the control voltage. In more complex
magnetic amplifiers, the input, or control signal,
may be either d-c or a properly phased a-c voltage.
In addition to saturable reactors, there are
numerous types of magnetic units in use, including
voltage regulators, low- and high- frequency
amplifiers, and servomotor controllers. The
purpose of this discussion is to present the
operating principles of these devices and to give
representative examples of magnetic circuits
employed in missile electrical equipment. To
understand the theory of magnetic amplifiers, it is
necessary that you understand the theory of
magnetism and magnetic circuits. This information
may be found in the Navy training course Basic
Electricity, NAVTRA 10086. The basic principles
of operation of magnetic amplifiers are also
discussed in that text. The quals require this
knowledge at the B-4 level.
Magnetic amplifiers are not new; saturable core
control has been used as early as 1885. In the
United States, saturable core devices have been
used to control heavy electrical machinery since
about 1900. Refinement and improvement have
made magnetic amplifiers usable for more delicate
and accurate controls. They are now used for gun
and launcher servo systems; high- speed digital
computers; and pulse-forming, memory, and
scanning circuits in radio, radar, and sonar
equipment. Development of reliable semiconductor
rectifiers, magnetic-core material of high
permeability, improved input and output devices,
automatic means of winding toroidal cores, use of
sealed, self-contained units, and new means of
testing, matching, and grading have greatly
expanded the use of magnetic amplifiers.
APPLICATIONS OF MAGNETIC
AMPLIFIERS
The magnetic amplifier has found application in
many different type circuits. These circuits may
employ diodes, vacuum tubes, and transistors. Such
circuits may be found in voltage regulators (d-c
and a-c), servoamplifiers, and
130
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
audio amplifiers. The GMM will be mainly
concerned with their application in servo systems
and voltage regulators.
The application of magnetic amplifiers varies
with the different launching systems. In the Mk 9
launching system, the EP8 and EP9 control panels
house the amplifiers. They are located on the
transfer cars, A side and B side. The transfer cars
are operated by hydraulic power, but the amplifiers
amplify the electrical signals that actuate the
switches. The power panel is the voltage supply
source for magnetic amplifiers in the system. There
are magnetic amplifiers in the lift assembly and
power drive unit, in the cell door and missile stop
mechanism assembly, in the extractor assembly,
subassemblies, and power drive. This transfer car is
used to move a selected missile from its cell to the
stage 1 rammer rail in a loading operation, or to
move the missile to the checkout handling rail for a
checkout or strikedown operation. In stow
operation, the car will return the missile from the
stage 1 rammer rail to a selected cell and it will
also return a missile from the handling rail to a
selected cell after completion of checkout or when
arming the ship. In all these functions, magnetic
amplifiers are used to amplify the signals. If the
magnetic amplifier is out of adjustment, the
transfer car movement will be slow or sluggish or it
will hunt. You need the OP for the launching
system for detailed steps in the adjustment of
magnetic amplifiers.
APPLICATIONS IN SERVOMECHANISMS
One of the most frequent uses of magnetic
amplifiers in electrical equipment is in
servomechanism systems. In these applications, the
magnetic units have the desirable features of long
life, minimum need for servicing, and the ability to
handle large amounts of power for energizing
electric motors and other load actuating devices.
Motor Controller
Figure 5-11 shows a magnetic servoamplifier
which controls the voltages for both phases of a
two-phase electric motor. The input signals for the
magnetic amplifier are produced by a phase
detector. These drive V1 and V2, which are
connected as a cathode coupled paraphase
amplifier working into two saturable reactors. Note
that the magnetic amplifier is working with cathode
tube amplifiers.
With zero input, both tubes (fig. 5-11) draw
equal amounts of current in the plate circuits.
These currents are insufficient to saturate the cores
of the reactors; and therefore, the impedance of
each load winding is very high and the resulting
load currents of each load winding is very small. In
this condition the circuit is a balanced bridge as
indicated in part (B) of figure 5-11, and the motor
does not rotate since in-phase voltages are applied
to the motor windings.
When an input control signal is supplied from
the phase detector, one of the tubes (depending
upon the polarity and amplitude of the signal) goes
into heavier conduction than the other. Under full
conduction conditions, the reactor in one plate
circuit then appears as a low impedance and the
other reactor approaches the open-circuit condition.
The bridge is then unbalanced; and capacitor C5 is
effectively connected in series with one of the
motor windings, where it causes a phase shift and
the motor begins to rotate.
131
GUNNERS MATE M 1 & C
Assume, for example, that V1 (fig. 5-11) goes
into heavy conduction and that V2 is at effective
cut-off. The inductance of the secondary of Tl is
then practically zero and motor winding WI is
connected across the a-c source. The inductance of
the secondary of T2 is high so that the winding
resembles an open circuit; and motor winding W2
is then connected across the a-c source through the
phasing capacitor. The phase relations, of the
resulting currents cause the motor to rotate in a
direction determined by which winding is
connected in series with the capacitor. Upon
reversal of the control signal, the conditions
described also reverse; and W1 is placed in series
with the capacitor so that the motor then turns in
the opposite direction.
POWER SUPPLY REGULATOR
The equipment power supplies of missile
systems must meet certain basic requirements
which include ruggedness, long life, and freedom
from excessive maintenance problems. To meet
these requirements, the development of power
supply equipment has resulted, in many cases, in
the elimination of the electron tube as the chief
cause of failure. The magnetic amplifier has been
used to replace the complex arrangements usually
necessary for good voltage regulations; and the
solid-state power diode is often employed instead
of the fragile vacuum tube. An example of a circuit
with these components is shown in figure 5-12.
Magnetic Amplifier Control
The circuit is a conventional full-wave bridge
rectifier utilizing a magnetic amplifier to control
the output and also a Zener diode as a part of the
regulating system. The Zener diode element is a
solid-state equivalent of the gaseous regulator tube
and maintains a constant voltage across the
terminals regardless of variations of the current it
conducts, within the specified operating range. In
the schematic shown (fig. 5-12), the connection of
the Zener diode is the reverse of that of an ordinary
rectifying diode since in this example it is the
inverse breakdown voltage characteristic which is
employed for regulation.
Current flow (fig. 5-12) during one half cycle is
through the load, choke Ll, diode D3, the
secondary of Tl, and diode Dl, then returning to
ground through SRI of the reactor. During the other
half cycle, the current flows through the load, Ll,
SR2, D2, the secondary of Tl, and D4 to ground. In
addition to the load current, there is conduction
through D5 and R3 and also through R2 and Rl.
The control winding of the magnetic amplifier is
energized by the voltage between the junction of Rl
and R2 and the upper terminal of the Zener diode,
D5. When the output voltage is of the proper value,
the potential across the control winding (and
therefore the current through it) sets the magnetic
bias of the reactors at the operating point, which is
well up on the magnetization curve to obtain a high
percentage of the source voltage.
If the output voltage tends to rise, the voltage at
point a remains constant due to the action of the
Zener diode; but the voltage at point b increases.
This causes a change in the current flowing in the
control winding so that the bias point is shifted to a
value that results in lower conduction in the load
coils. As a result, the voltages across SR1 and SR2
are increased and the output voltage decreases.
When the output voltage tends to decrease, the
potential at point b falls with respect to that at point
a and the control current changes the bias to a point
of higher conduction.. This lowers the voltage
drops across the a-c coils of the reactors and
increases the valve of the output. Capacitors Cl and
C2, together with Ll, are connected to form a pisection filter which
132
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
smoothes the output to give a nearly pure d-c
voltage. Resistor R2 is adjustable, being set to the
value for optimum operating voltage in normal use.
It also provides a means for making adjustments to
compensate for any changes that occur in the
circuit components.
A gas-filled regulator tube (VR-75) could be
used in place of the Zener diode. The voltage
regulation and operation would be the same, but a
VR tube requires much higher power supply
voltages.
ZENER DIODES. - If you looked in the index of
any of the basic texts previously mentioned you
would not find the word Zener listed. Zener effect
and Zener diodes, however, are given some
discussion in chapters 2 and 3 of Basic Electronics,
NAVTRA 10087. Avalanche breakdown is
sometimes called Zener effect, after the American
physicist Clarence Zener, who made theoretical
investigations of the problem of electrical
breakdown of insulators. The breakdown
mechanism in PN transistor junctions is not the
same as in insulators but, in spite of this, the name
Zener voltage is often given to breakdown voltage
of junctions. The reverse voltage at which the
current suddenly begins to make its sharp descent
is called Zener breakdown voltage. The use of the
word "breakdown" does not mean that the diode is
destroyed, but rather that the normal negative
reverse current increases suddenly and sharply. A
typical Zener diode curve is shown in figure 5-13.
Zener diodes are used chiefly as regulation and
reference elements. When a reverse voltage is
applied, no current will be passed until there is a
breakdown in the convalent bond of the atoms,
causing a sharp increase in current flow in the
reverse direction. If this happened in a regular PN
junction diode, it would be considered defective,
but Zener diodes are designed to be self- healing
and can be used repeatedly without damage. The
point of breakdown or avalanche is built into the
diode and can be made to occur at various voltages.
In figure 5-13, approximately 20 volts is applied.
PUSH-PULL. - A push-pull amplifier is a
balanced amplifier. There are two identical signal
branches connected so as to operate in
phase opposition and with input and output
connections each balanced to ground.
A paraphase amplifier is essentially a
combination amplifier and phase inverter. It is
sometimes used in place of transformers to operate
push-pull circuits. Paraphase amplifiers are
described in Basic Electronics, NAVTRA 10087.
Transistor Amplifiers
Transistor amplifiers may be used in place of
electron tube amplifiers. A transistor amplifier
must
have
three-element
(two-junction)
semiconductors to amplify a signal, just as a threeelement electron tube is needed for amplification.
There are also three types of transistor amplifiers,
according to which part is grounded: grounded
emitter, grounded base, and grounded collector.
The above text describes the theories and operating
characteristics of vacuum tubes and of transistors.
Transistors are designed to perform the same
functions as vacuum tubes. As they are solid-state
semiconductors, they are much less fragile than
vacuum tubes. Of course, failure can be caused by
misuse, such as current overloading, or application
of too high a voltage. Faults in manufacturing, or
flaws in the material can cause mechanical failure.
Radiation affects them so they must be shield.
Most failures are
133
GUNNERS MATE M 1 & C
caused by the effects of moisture on the surface.
Hermetic sealing of the transistors by
manufacturers is now the usual practice. Since
transistors are so very small, a speak of dust falling
across a junction can completely short-circuit it. A
dust free atmosphere is a practical necessity in a
transistor-fabrication plant.
It is believed that transistors will far outlast
vacuum tubes. At present no missile launching
system has changed completely over to transistors,
but one gun system has, so you can expect this
change in the future. Magnetic amplifiers will
continue to be used, alone and with transistors
instead of vacuum tubes.
SERVOAMPLIFIER
The purpose of a servoamplifier is to control an
output in a manner dictated by an input. Normally,
the servosystem's signal input is at a low energy
level and must be greatly increased to perform an
appreciable amount of work. This is the job of the
servoamplifier. The amplifier controls a large
power source which is activated by a low-powered
error signal. This is shown in figure 5-14A. Figure
5-14B shows a simple power control using a triode
as the controlling element and a battery as the
power reservoir.
There are just about as many different amplifiers
as there are jobs for amplifiers to do. Each part of
the amplifier is selected to do a particular part of
the total job. You can't just look at a circuit and
understand why everything is there. The best way
to analyze an amplifier is to divide it into stages,
coupling circuits, decoupling circuits, and biasing
networks. In Basic Electronics, NAVTRA 10087
you studied each of these circuits-you know what
they are supposed to do. Basic Electricity,
NAVTRA 10086 tells you that servoamplifiers
may be of the vacuum-tube type or the magnetic
type, and combinations of these. Basic Electronics,
has a chapter on the use of electron tubes for
amplifying voltage and power, and another chapter
on servosystems, including servoamplifiers.
Servoamplifiers can be broadly divided into
functional stages. You have learned how the error
signal is selected, and modulated or demodulated
to suit the individual amplifier. The first stage or
stages of amplification increase the voltage of the
error signal. When the signal voltage is amplified a
sufficient amount, it is used as the input to the
power stage. Here the primary concern is current
delivered at a steady voltage under load conditions.
The push-pull type amplifier is extensively used in
missile servo- systems. A push-pull amplifier is
preceded by a phase inverter or paraphase
amplifier. The power stage may be one or more
stages, depending on the power output needed.
In general, the higher the gain of the amplifier,
the tighter the control and the more accurate the
servosystem. An increase in the system gain will
reduce the system velocity errors and increase the
speed of response to inputs. An increase in system
gain also reduces those steady-state errors resulting
from restraining torques on the servo load.
However, to obtain these advantages, the
servosystem must pay a price in the form of a
greater tendency toward instability. A linear servo
system is said to be stable if the response of the
system to any discontinuous input does not exhibit
sustained or growing oscillations. The highest gain
that can be used is limited by consideration of
stability.
Review of Use in Launching System
The preceding course, Gunner's Mate M
(Missiles), 3&2, NAVTRA 10199, described and
illustrated servosystems (with amplifiers) used to
control error signals in launcher power drives.
Amplifiers associated with ordnance actually do
more than amplify. Some power drive amplifiers
change the incoming a-c synchro signal to a d-c
signal that can be used-to control a servomotor. In
amplifiers associated with ordnance equipment, the
power supply normally is built into, and therefore
is physically part of the amplifier. Many amplifiers
in ordnance equipment have two rectifiers: one in
the power supply to provide the required d-c
voltages and the other to convert the a-c input
signal to a d-c signal.
Examples of other amplifier functions include
stabilizing, synchronizing, speed limiting, position
limiting, and current limiting. Amplifiers
associated with ordnance equipment are nearly
always classed as power amplifiers. A voltage
amplifying stage is used only if it is necessary to
increase an input voltage. The number and type
134
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
of amplifier functions is determined to some extent
Servosystems using push-pull amplifiers must be
by the type of output controlled by the amplifier.
balanced so that when there is no signal input to
the amplifier, its output will be zero, and the
servomotor will stand still with no creep. The pushGain, Phase, and Balance Adjustments
pull amplifier must ensure equal torque in both
In many servo systems the gain of the amplifier directions of the servomotor.
can be varied by an adjustment. The gain
Gain, phase, and balance adjustments are often
adjustment governs the amplitude or amount of the present in one amplifier. These adjustments tend to
signal voltage applied to the amplifier or one of its interact so that when one of them is changed, it
stages. Normally, the highest gain possible, with may affect the others. Therefore, after making
the servosystem posessing a satisfactory degree of anyone adjustment it is a good practice to check the
stability, is the most desirable.
other adjustments.
In a-c servosystems another adjustment which
can control the sensitivity of the system is the Magnetic Amplifiers Used as
phase adjustment. The phase adjustment is used to Servocontrol Amplifiers
shift the phase relationship between the signal
voltage and a reference voltage. In an amplifier
A somewhat different type of servoamplifier
with phase shift control the grid signal is shifted in used in launching equipment is the magnetic
phase with reference to the plate voltage of a tube. amplifier.
The tube's firing point is delayed or advanced,
The servomotor used in conjunction with the
depending upon the phase Shift of the grid signal. magnetic amplifier shown in figure 5-15 is an a-c
The phase shift can vary the firing time of the tube type. The uncontrolled phase may be connected in
over the plate's entire positive alternation.
parallel with transformer T1 by utilizing a phaseA phase control is included in some servo- shifting capacitor, or it may e connected to a
systems using a-c motors. The two windings of the different phase of a multi phase system. The
a-c servosystems using a-c motors. The two controlled phase is energized by the magnetic
windings of the a-c servomotor should be amplifier, and its phase relationship is determined
energized by a-c voltages that are 90° apart. This by the polarity of the d-c error voltage.
phase adjustment is included in the system to
The magnetic amplifier consists of a transformer
compensate for any phase shift in the amplifier (Tl) and two saturable reactors, each having three
circuit. The adjustment may be located in the windings. Notice that the d-c bias current flows
control amplifier, or, in the case of a split-phase through a winding of each reactor and the windings
motor, it may be in the uncontrolled winding.
are connected in series-aiding. This bias current is
supplied by a d-c bias power source. The d-c error
current also flows through
135
GUNNERS MATE M 1 & C
an output that varies in both polarity and
magnitude. The push-pull (sometimes called
duodirectional) magnetic amplifier meets those
requirements. If control current is zero, load
current also is zero. Likewise, if the control current
increases in a positive direction, load current also
increases in a positive direction.
Servoamplifiers in Launching Systems
a winding in each reactor; however, these windings
are connected in series-opposing.
The reactors, Z1 and Z2, are equally and
partially saturated by the d-c bias current when no
d-c error signal is applied. The reactance of Zl and
Z2 is now equal, resulting in points Band D being
at equal potential. There is no current flow through
the controlled phase winding.
If an error signal is applied, causing the current
to further saturate Z2, the reactance of its a-c
winding is decreased. This current through Z1 will
tend to cancel the effect of the d-c bias current and
increase the reactance of its a-c winding. Within
the operating limits of the circuit, the change in
reactance is proportional to the amplitude of the
error signal. Hence, point D is now effectively
connected to point C, causing motor rotation.
Reversing the polarity of the error signal will cause
the direction of rotation to reverse.
The basic magnetic servoamplifier discussed
above has a. response delay equal to approximately
6 to 20 Hz. In some applications this delay would
be excessive, creating too much error. However,
this delay can be reduced to about one Hz. by using
special push-pull circuits.
Polarized magnetic amplifiers can distinguish
between control current polarities, but they can
change only load current magnitude, not load
current direction (polarity). Nearly all servo
devices associated with ordnance equipment power
devices require magnetic amplifiers with
The amplification of the train and elevation
signals is an outstanding example of the use of
servoamplifiers in launching systems. It was
applied in the training and elevation of guns on gun
mounts, and when missile launching systems were
designed, the devices and methods were borrowed
for this new application.
The small electrical input signals must be
amplified into usable signals of sufficient
magnitude to operate the electrohydraulic servovalves of the receiver-regulators. The amplification
system is common to both power drives and
consists of a dual channel magnetic amplifier,
made up of four magnetic amplifier stages mounted
on a common chassis, and a power supply. One
channel of the amplifier services the train power
drive and the other channel services the elevation
power drive. In each channel, one magnetic
amplifier stage is the primary servo- system
amplifier and the other is the velocity system
servoamplifier.
The primary system servoamplifier receives
position error voltage signal from the 1- and 36speed synchro control transformers in the receiverregulator. The amplifier also receives an unfiltered
velocity signal from the rate generators in the
remote, local, or dummy director. It mixes and
amplifies these signals and uses the resultant output
to operate the primary electro- hydraulic
servovalve. The input circuit of the primary
amplifier limits the voltages to the magnetic
amplifier stage control windings and provides
automatic changeover from the l-speed signal
control to the 36-speed signal control when the
launcher position error reduces to less than five
degrees of correspondence with the order signal. It
also receives an amplifier load supply voltage and
a synchro offset voltage from the power supply.
The train primary amplifier input circuit applies the
offset voltage to the
136
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
output of the I-speed synchro control transformer
for stick-off purposes. The offset voltage is not
applied to the elevation primary amplifier.
The velocity system servoamplifier receives a
filtered velocity signal from the rate generators in
the remote, local, or dummy director. The amplifier
also receives an electrical feedback signal from the
velocity and integration potentiometers of the
receiver regulator. The velocity amplifier mixes
and amplifies these signals and . uses the resulting
output to operate the velocity electrohydraulic
servovalve. The input circuit of the velocity
amplifier provides the gain control I for the
velocity input and voltage controls for the
potentiometers; it mixes the velocity signal input
with the potentiometer signals, and applies the
resulting signal to the control windings of } the
magnetic amplifier stage.
The potentiometer voltage supply circuit
provides a frequency-sensitive, regulated, and
filtered voltage for the velocity and integration
potentiometers of the receiver regulator. The
regulated voltage supply prevents fluctuation of the
integration and velocity system outputs and
compensates for the varying line frequencies to
stabilize the electric drive motor and B-end error of
the power drive.
Repair, Replacement, or Adjustment
Unless specifically directed otherwise, defective
amplifier units are removed as a unit and ;
replaced. They may be returned to the vendor for
repair. Only one adjustment is normally J
necessary on the power panel. VOLT ADJ should
be set to give an output of 48.0 v at terminals 1 and
2 with all amplifier panels connected, and 115 v
400 hertz applied to the power panel inputs 28 and
29 (Mk 9 Mod 0 launching system).
Some adjustments made at the factory are not
changed on shipboard. Hermetically sealed
components are always replaced rather than
repaired. Before replacing such a unit, double
check all associated circuitry (resistors, wiring,
etc.). When a defective component is replaced,
adjust it and the channel in which it operates,
following the instructions for your equipment.
All amplifier channel balance adjustments have
been set at the factory. On installation, and weekly
thereafter, the balance of both stages of
amplification should be checked, using the meters
installed in the amplifier panel.
Demodulators are balanced at the factory and no
further adjustment should normally be necessary
except on replacement, or in case the setting at
balance adjustment is disturbed.
Rectifiers are very important components of
magnetic amplifiers. Series rectifiers may be
checked by the use of a cathode-ray oscilloscope.
Whenever possible,. the waveform across a
rectifier suspected of being defective should be
compared to waveforms observed across other
rectifiers in the same circuit.
SYNCHROSYSTEMS
The preceding course, Gunner's Mate M
(Missiles) 3&2, NAVTRA 10199 described and
illustrated uses of synchros and synchro data in
missile launching systems, so we'll just have a brief
review.
Synchros are seldom used alone. They work in
teams and when two or more synchros are
interconnected to work together, they form a
synchro system. Such a system may, depending on
the types and arrangement of its components, be
put to uses which vary from positioning a sensitive
indicator to controlling the motors which move a
launcher weighing many tons. If the synchro
system provides a mechanical output which does
the actual positioning, as in the case of the
indicator, it is a torque system. If it provides an
electrical output which is used only to control the
power which does the mechanical work, it is a
control system. Control synchros are usually part
of a larger system called a servo (automatic
control) system. In many cases, the same system is
called upon to perform both torque and control
functions.
The individual synchros which make up a torque
system are designed to meet the demands placed on
them by the mechanical load, which such a system
is expected to handle. However, the comparatively
small mechanical output of a torque synchro
system is suitable only for very light loads. Even
when not heavily loaded, a torque system is never
entirely accurate. When larger amounts of torque,
or a higher degree of accuracy, or both are
required, torque synchro systems give way to
control synchros used as
137
GUNNERS MATE M 1 & C
components of servosystems. Synchros control, issue the proper correcting order to change existing
and servos provide the torque. The distinguishing conditions to those required.
5. It must adequately carry out its own correcting
unit of any synchro control unit is the control
order.
transformer (CT).
In functional terms the components normally
found in a servosystem using synchros are
A servo, servosystem, or a servomechanism (the identified as a data input device, a data output
three terms mean the same thing) is an automatic device, an amplifier, a power control device, a
control device widely used in the Navy and drive motor, and a feedback device.
distinguished by several special characteristics.
There are many different types of servosystems, Servo Terminology
and not all of them use synchros. The purpose of
In addition to those already mentioned, a number
servo systems in which control synchros are used is
to supply larger amounts of power and a greater of specialized terms are used in connection with
degree of accuracy than is possible with synchros servosystems: The more common of these are
alone.. Another equally important characteristic of defined here.
OPEN-CYCLE CONTROL of a servosystem
the servo is its ability to supply this power
automatically, at the proper time, and to the degree means actuation of the servo solely by means of the
regulated by the need at each particular moment. input data, the feedback device being either
All that the system requires. To perform the removed or disabled. It should be clearly
specific task for which it is designed is an order understood here that any mechanism must include
defining the desired results. When such an order is a feedback provision to be classified as a servo; but
received, the servo compares the desired results in testing certain servo characteristics, an openwith the existing conditions, determines the cycle control is often useful. Under such conditions
requirements, and applies power accordingly, the elements involved are frequently referred to as
automatically correcting for any tendency toward an open servoloop.
CLOSED-CYCLE CONTROL refers to normal
error which may occur during the process.
There are various ways in which these results are actuation of the system by the difference between
obtained. Whether it be amplidyne or hydraulic input and output data, with the feedback device
power drives of many different types, the end result operative.
CONTINUOUS CONTROL is used to describe
is always the same and that is the positioning of the
launcher in accordance with input orders received uninterrupted operation of the servosystem on its
from remote control stations. To function in this load, regardless of the smallness of the error.
DEVIATION or error of a servo, is the
manner a servosystem must meet five basic
difference between input and output.
requirements:
ERROR SIGNAL or error voltage is the
1. It must be able to accept an input order corrective signal developed in the system by a
defining the desired result, and translate this order difference between input and output.
INSTRUMENT SERVOS and POWER
into usable form.
2. It must feed back, from its output, data SERVOS are designations used to classify servoconcerning the existing conditions over which it mechanisms according to their power output. An
instrument servo is one rated at less than 100 watts
exercises control.
3. It must compare this data with the desired maximum continuous output; a servo whose rating
result expressed by the input order and generate an exceeds this amount is a power servo.
error signal proportional to any difference which
this comparison shows.
Classification of Servos by Use
4. It must, in response to such an error signal,
A convenient classification of servosystems can
be made in accordance with their use, the
Servosystems Using Synchros
138
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
device. The better way is to align all synchros to
electrical zero. Units may be zeroed individually,
and only one man is required to do this work.
Another advantage of using electrical zero is that
trouble in the system always shows up in the same
way. For example, in a properly zeroed TX-RT
system, a short circuit from S2 to S3 causes all
receiver dials to stop at 60 degrees or 240 degrees.
In summary, zeroing a synchro means adjusting
it mechanically so that it will work properly in a
system in which all other synchros are zeroed. This
mechanical adjustment is accomplished normally
by physically turning the synchro rotor or stator.
Synchro, Servo and Gyro Fundamentals, NAVTRA
10105, describes standard mounting hardware and
gives simple methods for physiclly adjusting
synchros to electrical zero. Additional information
about synchros may also be obtained from Military
ZEROING SYNCHROS
Handbook MIL-HDBK-225 (AS) Synchros
If synchros are to work together properly in a Description and Operation (supercedes OP l303).
system, it is essential that they be correctly
connected and aligned in respect to each other and Electrical Zero Conditions
to the other devices, such as directors and
For any given rotor position there is a definite
launchers with which they are used. Needless to
say, the best of ordnance equipment would be set of stator voltages. One such rotor-positionineffective if the synchros in the data transmission stator-voltage condition can be established as an
circuits
were
misaligned
electrically
or arbitrary reference point for all synchros which are
mechanically. Since synchros are the heart of the electrically identical.
transmission systems, it only stands to reason that
CONTROL TRANSFORMERS. - A synchro
they must be properly connected and aligned
control transformer is zeroed if its rotor voltage is
before any satisfactory firing can be expected.
Electrical zero is the reference point for minimum when electrical zero voltages are applied
alignment of all synchro units. The mechanical to its stator. Turning the CT's shaft slightly
reference point for the units connected to the counterclockwise will produce a voltage between R
synchros depends upon the particular application of 1 and R2 which is in phase with the voltage
the synchro system. As a GMM on board ship, between Rl and R2 of the synchro transmitters, CX
.your primary concern with mechanical reference or TX, :supplying excitation to the CT stator.
point will be the centerline of the ship for launcher Electrical zero voltages, for stator only, are the
train and the standard reference plane for launcher same as for transmitters and receivers.
elevation. Remember that whatever the system, the
electrical and mechanical reference points must be Zeroing Procedures
aligned with each other.
The procedure used for zeroing depends upon
There are two ways in which this alignment can
be accomplished. The most difficult way is to have the facilities and tools available and how the
two men, one at the transmitter and one at the synchros are connected in the system. Synchros
receiver or control transformer, adjust the synchros may be zeroed by use of only a voltmeter synchro
while talking over sound powered telephones or testers, or other synchros in the system.
some other communication
most common of which are as position servos and
velocity servos. The position servo is used to
control the position of its load and is designed so
that its output moves the load to the position
indicated by the input. The velocity servo is used to
move its load at a speed determined by the input to
the system.
Many servosystems cannot be fitted into either
category. For example, a third type of servo is used
to control the acceleration rather than the velocity
of its load. And special applications of the different
types are used for calculating purposes, the servo
making a desired computation from mechanical or
electrical information and delivering the answer in
the form of mechanical motion, an electrical signal,
or both.
139
GUNNERS MATE M 1 & C
When
zeroing
differentials
and
control
transformers, it is helpful to have a source of 78
volts (10.2 volts .for 26-volt umts).
Regardless of the method used, there are two
major steps in each zeroing procedure: first, the
coarse (or approximate) setting, and second, the
fine setting. Many units are marked in such a
manner that the coarse setting may be
approximated physically on standard units; an
arrow is stamped on the frame and a line is marked
on the shaft extension.
SYNCHRO TESTERS
Synchro testers of the type shown in figure 5-17
are used primarily for locating a defective synchro.
They also provide a fairly accurate method of
setting synchros on electrical zero. To zero a
synchro with the tester, connect the units as shown
in figure 5-17 and turn the synchro until the tester
dial reads 0 degrees. This is the approximate
electrical zero position. Momentarily short S1 to
S3 as shown. If either the synchro or tester dial
moves, the synchro is not accurately zeroed, and
ZEROING A CONTROL TRANSFORMER should be shifted slightly until there is no
USING AN A-C VOLTMETER.-Using a movement when Sl and S3 are shorted.
voltmeter with a 0- to 250- and 0- to 5-volt scale,
NOTE: By exercising proper caution it is
control transformers may be zeroed as follows:
possible to perform all the preceding zeroing
1. Remove connections from control transformer procedures using 115 volts where a source of 78
volts is not available. If 115 volts is applied instead
and reconnect as shown in figure 5-16A.
2. Turn the rotor or stator to obtain minimum of 78 volts, do not leave the synchro connected for
more than 2 minutes or it will over- heat and may
voltage reading.
3. Reconnect meter as shown in figure 5-16 B, be permanently damaged.
and adjust rotor or stator for minimum reading.
4. Clamp the control transformer in position and Summary
reconnect all leads for normal use.
The described zeroing methods apply to all
standard synchros and prestandard Navy synchros.
Before testing a new installation and before
hunting trouble in an existing system, first be
certain all units are zeroed. Also, be sure the
device's mechanical position corresponding to
electrical zero position is known before trying to
zero the synchros. The mechanical reference
position corresponding to electrical zero varies;
therefore, it is suggested that the instruction books
and other pertinent information be care. fully read
before attempting to zero a particular synchro
system. The MRCs and the OP for the system
should be studied, as there are likely to be some
differences from the general instructions given in
NAVTRA 10105. For example, OP 2665, volume
3, Guided Missile Launching System Mark 13 Mod
0, gives step-by-step instructions for replacement
and adjustment procedures for train and elevation
regulator CTs. If an operational check indicates
that a synchro control transformer in the regulator
is not operating properly, replace and adjust the
synchro.
140
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
Note that you do not attempt to adjust. the
malfunctioning synchro; you remove that one and
put in a new one, then adjust that. Two tests with a
voltmeter are described for zeroing the synchro,
and then the method of checking that the newly
installed synchro is not 180 degrees out of phase.
The power source used is
115-v, 400-hertz supplied from the launcher
position generators to the S1 and S3 terminals
through R1 and R2 terminals.
Figure 5-18 shows a train synchro gear assembly
which points out the synchros and the dials. The
elevation synchro gear assembly is very similar,
but it has a sixth synchro which
141
GUNNERS MATE M 1 & C
supplies the coarse (2X) elevation error signals in a
remote jettison operation. It is mounted on the
bracket holding the indicating dials. All the
synchros are held in position with capscrew held
lugs, making alignment easier.
MAINTENANCE
Synchro units require careful handling at all
times. NEVER force a synchro unit into place,
NEVER drill holes in its frame, NEVER use pliers
on the threaded shaft, and NEVER use force to
mount a gear or dial on its shaft. Two basic rules
exist:
1. IF IT WORKS- LEAVE IT ALONE.
2. IF IT GOES BAD-REPLACE IT.
mounting of the synchro in the equipment. Early
consideration should be given to the possibility of
friction when troubleshooting faulty synchro
operation. The synchros are not tested individually
but are checked in the shipboard performance tests.
If the test does not meet the standard requirements,
then a search is made for the faulty component
Adjustments
While adjustments are a vital part of
maintenance, they are too numerous to be covered
here. Instead, a word of caution: At the time of
installation, your control equipment was adjusted
by well qualified personnel using special tools and
equipment. For this reason, adjustments should be
undertaken only after qualified personnel have
verified that an adjustment is necessary. A good
habit to cultivate when making adjustments is to
scribe gears at their original point of mesh, and
count threads or teeth to the position of the new
adjustment. These measures will prove most
valuable when an adjustment is later found to be
incorrect or unnecessary.
Synchros are no longer considered as repairable
items. Replaced synchros should be disposed of in
accordance with current instructions. Unless in an
emergency with no replacement available, NEVER
take a unit apart or try to lubricate it. The gearing
(fig. 5-18) should be lubricated, using an atomizer,
any time the cover of the receiver-regulator is
removed, but do not lubricate switches, or the New Installations
tachometer. Use the MRC for instructions.
In a newly installed system, the trouble probably
TROUBLESHOOTING SYNCHRO SYSTEMS is the result of improper zeroing or wrong
connections. Make certain all units are zeroed
Shipboard synchro troubleshooting is limited to correctly; then check the wiring. Do not trust the
determining whether the trouble is in the synchro color coding of the wires. Best check them out with
or in the system connections; but if something is an ohmmeter. A major source of trouble is
wrong with the unit, replace it. Generally, there are improper excitation. Remember, the entire system
two major categories of troubles occurring in must be energized from the power source for
synchro systems. These are (1) those likely to proper operation.
occur in new installations, and (2) those likely to
occur after the system has been in service a while.
Existing Installations
All synchro casualties are not electrical,
In systems which have been working, the most
however, and do not require special equipment to
uncover. One fairly common trouble affecting common trouble sources are:
synchro operation is friction. Bearings must be
Switches-Shorts, opens, grounds, corrosion,
especially clean, allowing the synchro rotor to turn
freely. The slightest sticking will cause an error in wrong connections.
Nearby equipment-Water or oil leaking into
route position, because there is little torque on the
rotor when it is nearly in agreement with the synchro from other devices. If this is the trouble,
incoming signal. Friction may also be caused by correct it before installing a new synchro.
bent shafts and improper
142
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
Terminal boards-Loose lugs, frayed wires,
correction, and wrong connections.
Zeroing-Units improperly zeroed.
Wrong connections and improper zeroing in any
system are usually he result of careless work or
inadequate information. Do not rely on memory
when removing or installing units. Refer to the
applicable instruction book or standard plan. Tag
unmarked leads or make a record of the
connections. Someone else may need the
information.
OSCILLOSCOPE, DUMMY DIRECTOR,
AND DUAL TRACE RECORDER
changes in a varying voltage. These changes show
as wavy lines, and are not recorded. An
oscillograph records the alternating-current wave
forms or other electrical oscillations, using a pen
(or pens) to mark the trace on graph paper. The
trace can be studied and compared with previous
traces on the same equipment, or traces on similar
equipment as part of testing and troubleshooting
procedures. Both forms of the instrument make use
of cathode rays. The cathode ray oscilloscope was
described in the preceding course, and its
electrical-electronic operation explained.
OSCILLOGRAPHS
The words oscilloscope and oscillograph are
The use of Error Recorder Mk 12, or Mk 12
sometimes used interchangeably, but they do not Mod 1, which is primarily an oscillograph, is
represent the same equipment. An oscilloscope described in chapter 10. It is used with the Asroc,
shows on a fluorescent screen the
Tartar, and Talos missile launchers; Mk 9
143
GUNNERS MATE M 1 & C
is used with Terrier systems in the missile plotting
room to check the performance of the computer.
Telemetric Data Recording Set AN/SKH-l, located
in the director control room, includes a direct
reading oscillograph. A 20-pen Operations
Recorder is located in the missile plotting room to
record event signals from the two missile fire
control systems. Operational faults in the missile
system can be located by analysis of the tracings
made by the error records.
Telemetric Data Receiving, Recording, and
Scoring Set AN/SKQ-2 is used to receive and
record telemetric signals from guided missiles in
flight. It also can be used to provide 5-track
oscillographic records of the missile preflight
checkout.
Dummy Directors
The error recorder used by GMMs is used in
connection with the dummy director, described in
chapter 10.
The dummy director is a portable instrument
designed to produce dynamic signals required to
test launcher power drive performance. The Talos
launching system uses two Mk 1 Mod 6 dummy
directors, one for train and one for elevation tests.
They are used in conjunction with the launcher test
panel (EP3 panel of MLSC Mk 10 Mod 0). Other
test equipment supplied with the Mk 7 Mod 1
launching system includes: (1) one frequency
signal generator, (2) two limiter and demodulator
units, Model E, (3) a dual-channel oscillograph
with chart paper, black ink, and spare pens, (4) a
Triplett Model 630NA volt ohm-milliammeter or
equivalent, with test leads, and (5) test
instrumentation cabling. They are all used with the
launcher test panel.
Missile Stimulator Section
the missile stimulator: reference signal generator,
integrator, FM generator, synchronizer, pulse
delay, pulse signal generator, RF signal generator,
function generator, and missile relay control. It is
not used to test the launcher.
Dual Trace Recorder
Since the oscillograph has two channels, two
different traces may be taken at the same time. This
allows corresponding trace results to be compared
to learn more about the launcher operation.
Normally, three types of test traces are taken: Bend error traces, velocity .traces, and position
traces (fig. 5-19 A, B, C).
NOTE: Always calibrate the Brush oscillograph
before recording any traces.
The voltages for the B-end error trace are
obtained from the 36-speed synchro (in the
receiver-regulator), geared to the B-end response.
The synchro rotor is geared to rotate at 36-speed
while the stator is electrically connected to the 36speed synchro generator in the controlling test
director. The rotor output voltage (a 400-hertz
alternating voltage) indicates the error between the
generating director and the B-end response shaft.
The CT rotor output volt ages are circuited through
the control test panel to the limiter and
demodulator unit and then to the oscillograph.
The B-end position trace voltages also are
obtained from the 36-speed CT. Through the
proper switching on the control test panel, the
output voltage produced will indicate the B-end
position, and not error. The position output voltage
also goes through the limiter and demodulator unit,
and is recorded by the oscillograph.
The B-end velocity trace voltages are obtained
from the d-c tachometer generators located in the
receiver-regulator. The tachometer generators are
geared directly to the regulator B-end response
input shafts and furnish a d-c voltage which is
proportional to the B-end velocity. The tachometer
output is circuited through test instrumentation to
the oscillograph.
Do not confuse the missile simulator (chapter
10) with the missile stimulator section in the
Guided Missile Test Set AN/DSM-54(V), and later
models. The missile stimulator section provides
READING TEST TRACES.- Test traces are
simulated flight and guidance control signals to the
read
like ordinary graph curves. They illustrate the
missile, upon command of the program section.
error, position, or velocity of the launcher at the
The following modules make up
time the tests were made. Traces below the
144
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
145
GUNNERS MATE M 1 & C
zero reference line are of the opposite phase from
traces above the zero reference line. Be certain to
check the following when reading test traces: (1)
type of test being checked; (2) type of trace being..
used; (3) test conditions; (4) calibration on the left
margin of the graph; and (5) the time allotted for
each of the vertical graph divisions.
Use the calibration curve shown in figure 5-20 to
determine the exact B-end positions when they are
less than 5 degrees.
As the error and position trace voltages are
generated by the 36-speed synchros, difficulty may
arise in reading test traces if the error or position
reading is greater than 2.5 degrees. The 36-speed
sysnchro is geared to rotate 36 degrees for each 1degree movement of the launcher. A launcher
movement of 2.5 degrees therefore corresponds to
90 degrees rotation of the synchro. Since a synchro
generates maximum output with a 90-degree rotor
or stator displacement, the maximum trace
indication occurs at an error or position
displacement of 2.5 degrees. Error or position
traces greater than 2.5 degrees require a special
method of indication.
Since a complete revolution of a 36-speed
synchro corresponds to 10 degrees of launcher
movement, one complete cycle of a position or
error trace corresponds to 10 degrees of launcher
movement. For example, if the error or trace
position consists of 6 1/2 cycles, the trace will
measure 65 degrees of position or error (10 x 6.5).
1. Check the oil level at the main supply tank.
2. Check the oil level and all gear housings
associated with the train and elevation power
drives.
3. Lubricate the launcher components properly.
4. Charge the launcher accumulators properly.
5. Vent all hydraulic units properly.
6. Check the train warning bell operation.
7. Train the launcher through its maximum
limits to verify free and unobstructed launcher train
movements.
8. Elevate and depress the launcher guide arms
to their maximum limits of travel to verify free and
unrestricted guide arm movements.
On systems that have train and elevation air
motors, those are used for items 7 and 8. Power
drives are not activated for these checks.
CALIBRATION OF TRACE RECORDER.The missile launching system control and its test
panels may differ in switch arrangement,
identification, and circuitry not only for different
missile systems, but for different installations of
the same missile system. You will need the
elementary wiring diagrams to determine actual
identification of switches and positions, and what
each switch controls. Use only the special cables
supplied for interconnections of test instruments
and the test panels of the missile launching system
control.
After all these preliminary checks are made,
activate the launcher by switching on the EP1
power panel, and start the train and elevation
motors. The BP2 panel should be switched to
STEP control, and control switched to the EP3
panel. The test cables are connected to the EP3
panel. Allow the train and elevation power drives
to operate at least 30 minutes before making test
traces.
CAUTION: Do not move the guide arms or start
power drives unless it is known that the firing
cutout mechanism is adjusted properly. Failure to
do so may result in extensive damage to the firing
cutout mechanism.
9. Load the launcher rails with standard inert
missiles or equivalent unless specified otherwise
for the individual test being performed.
10. Check general condition of test
instrumentation and service as required. Use black
ink in the oscillograph so that test traces can be
reproduced clearly.
Two different methods of calibration are used.
Error and position traces are calibrated by one
method and velocity traces are calibrated by a
The oscillograph is calibrated during launcher second method.
The error trace uses three possible calibration
testing procedures; and the before any launcher
shipboard tests are made, the following general scales: a 10-minute full-scale calibration, a
checkoffs must be performed.
146
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
147
GUNNERS MATE M 1 & C
20-minute full-scale calibration, and a 2.5-degree
full-scale calibration.
The position trace is normally calibrated with
only one scale, a 2,5-degree full-scale calibration.
The velocity trace uses one calibration scale for
elevation and train tests. The train velocity trace is
calibrated with a forty-degree-per-second full-scale
calibration.
Allow the test equipment at least 10 minutes to
warm up before attempting any calibration
procedures. (Varies with different systems; check
your OP and the MRC.)
Obtain the instructions for calibrating the
oscillograph (error recorder) used with your missile
launching system and proceed with the calibration.
After you have completed the calibration of the
oscillograph, it is ready to be used in testing the
accuracy of the launcher. With the; Talos system,
these tests are numbered consecutively through test
No. 51 B. They are described in OP 3590 Guided
Missile Launcher, Mark 7 Mod 1, Description,
Operation, and Maintenance. There are many
similarities between the train and elevation tests,
but each power drive must be tested separately. For
example:
tests; and elevation (train) frequency response tests.
The error recorder is used to make traces in each
of the tests, the maximum operating errors are
calculated, and the traces are compared with
typical traces. Copies of typical traces are included
in the OP or OD. The traces made at installation of
the launching system on the ship are kept aboard
for comparison.
Elevation accuracy tests on shipboard include a
simple harmonic motion test, a static operation test,
and constant velocity tests. The same types of tests
are made for train accuracy. Constant velocity and
synchronizing tests are performed at different
speeds and at different angles of train and
elevation, each performed according to specific
instructions in the OP.
These tests are performed annually unless
circumstances require otherwise. A suspected
malfunction may require certain tests to be
performed more frequently. Operational tests may
be needed to determine if the launcher follows
order signals accurately, or to check some other
function of the launcher. All the men who perform
the test must be familiar with the equipment and
the procedure. Although you follow the steps
according to a checkoff list, studying the procedure
beforehand will do much for a smooth operation. If
Elevation (Train) Accuracy Test
you are the leading petty officer, you will check the
Test 1. Simple harmonic motion test.
work of the other men.
Test 2. Static test.
The launcher test equipment is stowed in the
Test 3. Five-degree-per-second constant veocity shipboard instrument storage cabinet when not in
test.
use.
Test 4. Ten-degree-per-second constant veocity
test.
SIMILARITIES AND DIFFERENCES
Test 5. Fifteen-degree-per-second constant
velocity test.
The principles explained in Basic Electricity,
Test 6. Elevation (train) velocity and NAVTRA 10086 and Basic Electronics, NAVTRA
acceleration test.
10087 apply to all the missile systems. The details
Tests 6A and 6B. Launcher elevation (train) of application of these principles in the different
synchronized indicator tests
weapon systems must be left to the OPs and ODs
The train power drive requires an additional t{
test in this series-25-degrees-per-second constant
velocity test.
Other tests in this group of fifty-one are
elevation (train) synchronizing tests, fixed
displacement; elevation (train) harmonic motion
synchronizing tests; elevation (train) synchro
power failure tests; elevation (train) main power.
failure tests; elevation (train) return to load
for each system. If you have acquired a firm
knowledge of the basic principles, you can
understand the use of them in the system in your
ship. If you are not so sure of your knowledge in
some areas, make a careful re-study of any part you
do not understand. Other petty officers can help
you. The complicated network of electrical and
electronic parts in a weapons system cannot be
kept in
148
CHAPTER 5 - ELECTRICITY AND ELECTRONICS
working order if you do not understand how it
Some of the newer electronic items that have
works. It is too sophisticated a system to maintain been placed in launching systems were introduced.
by guesswork.
As more use is made of transistors, printed circuits,
and miniaturized units, you need to apply the
knowledge of the principles to the particular uses.
SUMMARY
You will also need to develop skill in maintenance
This chapter points out the uses of different of these items.
electric and electronic devices in launching
While safety needs to be emphasized every day,
systems. It tells how they function and how you are and caution can never be relaxed around electrical
to test them, The basic principles of servos, equipment, the applicable safety regulations are
amplifiers, and synchros are applied to specific placed in chapter 12.
functions in the launching system.
149
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement