B&K Precision 4011 User Manual

BK PRECISION
QU
5 MHz
FUNCTION
GENERATOR
with DIGITAL DISPLAY
MUA USEEP - Operators Copy Volume 1
KKSC - Khon Kaen University - Science Fac.
KKSC29 - Physics
®
Supplier: Labquip International Limited EX AGE
LAO, OY 0 AA И FCIS
00004DC21
Mfr: B & K PRECISION
Function Generator/counter 5 Mhz
item: FT02/32 Model: 4011
TEST INSTRUMENT SAFETY
Normal use of test equipment exposes you to a certain amount of danger from electrical shock because testing must sometimes be performed where
exposed voltage is present. An electrical shock causing 10 milliamps of current to pass through the heart will stop most human heartbeats. Voltage as
low as 35 volts dc or ac rms should be considered dangerous and hazardous since it can produce a lethal current under certain conditions. Higher voltages
pose an even greater threat because such voltage can more easily produce a lethal current. Your normal work habits should include all accepted practices
to prevent contact with exposed high voltage, and to steer current away from your heart in case of accidental contact with a high voltage. You will
significantly reduce the risk factor if you know and observe the following safety precautions:
1. Don’t expose high voltage needlessly. Remove housings and covers only when necessary. Turn off equipment while making test connections in
high-voltage circuits. Discharge high-voltage capacitors after removing power.
2. If possible, familiarize yourself with the equipment being tested and the location of its high voltage points. However, remember that high voltage
may appear at unexpected points in defective equipment.
3. Use an insulated floor material or a large, insulated floor mat to stand on, and an insulated work surface on which to place equipment; and make
certain such surfaces are not damp or wet.
4. Use the time proven “one hand in the pocket” technique while handling an instrument probe. Be particularly careful to avoid contacing a nearby
metal object that could provide a good ground return path.
5. When testing ac powered equipment, remember that ac line voltage is usually present on some power input circuits such as the on-off switch, fuses,
power transformer, etc. any time the equipment is connected to an ac outlet, even if the equipment is turned off.
(continued on inside back cover)
TABLE OF CONTENTS
page
TEST INSTRUMENT SAFETY 2.122121 10 inside front cover
INTRODUCTION © ©... 0 oo, 3
SPECIFICATIONS . _ . . . 2 1111111 LL 1111110 4
CONTROLS AND INDICATORS aa 6
OPERATING INSTRUCTIONS . . . . 8
Frequency and Waveform Selection . 0.0.0000 8
Considerations .. 1.114 1112011114 11 4111111120 9
Duty Cycle Control ©... oo... 10
TTL/CMOS Output ©... ©... 0. li
HG
page
Voltage Controlled Frequency Operation . . . . . . ... ..... il
Output Protection Considerations . . . . . . . .. .. .. ..... 11
Function Generator Applications Guidebook . . . . . . . .. . .. 12
MAINTENANCE ... 22111 LL LL LL LL LL LL LL 120 13
Disassembly and Reassembly . . . . . .... ........... 13
Fuse Replacement . 1... 1242122011 LL LL LL LL 20 13
Line Voltage Selection 2.121204 11411 LL 11241110 13
Instrument Repair Service . 1... 1211114 11 4141120 14
CUSTOMER SUPPORT 1141444 LL LL LL LL 2220 17
WARRANTY SERVICE INSTRUCTIONS . ........... 18
LIMITED TWO-YEAR WARRANTY . . . . ......... .. 19
INTRODUCTION
The B+K Precision Model 4011 Function Generator is a versatile
signal source which combines several functions into one unit. Addition-
ally, the instrument provides the added convenience of a built-in fre-
quency counter. This permits more accurate determination of output
frequency than is possible with a simple calibrated dial. Coarse and fine
tuning controls permit precision settability of the output frequency. High
stability assures that the output frequency does not drift.
With this versatility, the unit has a vast number of applications in both
analog and digital electronics in the engineering, manufacturing, servic-
ing, educational, and hobbyist fields.
The heart of the function generator is a VCG (voltage-controlled
generator) that produces precision sine, square, or triangle waves over
the 0.5 Hz to 5 MHz range. This encompasses subaudible, audio,
ultrasonic, and RF applications. A continuously variable dc offset allows
the output to be injected directly into circuits at the correct bias level.
Variable syminetry of the output waveform converts the instrument
to a pulse generator capable of generating rectangular waves or pulses,
ramp or sawtooth waves, and slewed sine waves.
In addition to the above features, an external signal may be used to
sweep the output frequency or control operating frequency. This is useful
in situations where an externally controlled frequency is desirable.
SPECIFICATIONS
FREQUENCY CHARACTERISTRICS Amplitude Control
Waveforms Variable, 20 db range typical
Sine, Square, Triangle, + Pulse, + Ramp Attenuation
Range —20 db +1 db
DC Offset
0.5 Hz to 5 MHz in 7 ranges
Preset: £0.1 V typical
Resolution
4 digits Variable: +10V open-circuit, £5V into 50 Q
Tuning Range SINE WAVE
Coarse: 10:1, Fine: £5% of Coarse Setting Distortion
Variable Duty Cycle 1% typical at 1 KHz
15:85:15 Continuously Variable Flatness
Operating Modes +5% (.45 dB)
Normal, VCG (Voltage Controlled Generator)
SQUARE WAVE
Frequency Stability
Output frequency will not change more than 0.09% in 15 minutes Symmetry
after 1 hour warmup 0.5 Hz to 100 KHz <2%
OUTPUT CHARACTERISTICS Rise Time
<20 nS
Impedance
50 Q +10% TRIANGLE WAVE
Level Linearity
20 Y p-p Open-circuit, 10V p-p into 50 Q > 98% to 100 KHz
SPECIFICATIONS
TTL OUTPUT Time Base Accuracy
Level 0.8V to 2.4V +10 PPM (23°C £5°C)
Ce Display
<2
Rise Time <20 nS 4 digit LED
Duty Cycle 50% typical
POWER SOURCE
CMOS OUTPUT .
120/230 VAC + 10%, 50 / 60 Hz, internal jumper selectable
Max Frequency 2 MHz
Level 4V to 14 V +0.5V p-p, DIMENSIONS (Hx W x D)
Continuously variable 10-3/87 x 3-3/8" x 11-7/16” (26.4cm x 8.6em x 29.1em)
Rise Time <120 nS WEIGHT
VCG (Voltage Controlled Generator) INPUT | 4 1b. (1.8 kg.)
Input Voltage ACCESSORIES
0 - 10V +1V causes a 100:1 frequency change Instruction Manual
[Impedance Output Cable. BNC to Alligator Clips
10KQ +5%
FREQUENCY COUNTER
Accuracy
Time Base Accuracy + 1 count
CONTROLS AND INDICATORS
FRONT PANEL (Refer to Fig.1)
1.
2.
POWER Switch. Turns power on and off.
RANGE Switch. Selects output frequency range. Seven ranges
from 5 Hz to 5 MHz. Switch indicates maximum frequency of range
and is adjusted with COARSE FREQUENCY control to 0.1 times
the maximum. For example, if the 500 KHz range is selected, the
output frequency can be adjusted from 50 KHz to 500 KHz.
. FUNCTION Switch. Selects sine, square, or triangle waveform at
OUTPUT jack.
. OUTPUT LEVEL Control. Controls the amplitude of the signal
at the OUTPUT jack. Output level can be decreased by approxi-
mately 20db with this control.
. DC OFFSET Control. Enabled by the DC OFFSET Switch (12).
Clockwise rotation from center changes the DC offset in a positive
direction while counterclockwise rotation from center changes the
DC offset in a negative direction.
. OUTPUT Jack. Waveform selected by FUNCTION switch as well
as the superimposed DC OFFSET voltage is available at this jack.
. TTL/CMOS Jack. TTL or CMOS square wave, depending on the
position of the CMOS LEVEL switch (13) is output at this jack This
output is independent of the OUTPUT LEVEL and DC OFFSET
controls.
8.
9.
10.
"11.
12.
13.
14,
15.
16.
CMOS LEVEL Control. Rotating this control clockwise increases
the amplitude of the CMOS square wave at the TTL/CMOS jack.
VCG Jack. Voltage Controlled Generator input. Permits external
control of generator output frequency by a DC voltage input at this
Jack. A positive voltage will decrease frequency.
DUTY CYCLE Control. Enabled by the DUTY CYCLE Switch
(14). Rotation from center position adjusts the duty cycle of the
main OUTPUT signal.
-20DB Switch. When engaged, the signal at the OUTPUT jack is
attenuated by 20db.
DC OFFSET Switch. When engaged, enables operation of the DC
OFFSET control (5).
CMOS LEVEL Switch. When engaged, changes the TTL signal to
CMOS signal at the TTL/CMOS jack.
DUTY CYCLE Switch. When engaged, enables operation of
DUTY CYCLE control (10).
FINE FREQUENCY Control. Vernier adjustment of the output
frequency for ease of setting frequency.
COARSE FREQUENCY Control. Coarse adjustment of the out-
put frequency from 0.1 to 1 times the selected range.
. COUNTER DISPLAY. Displays frequency of internally gener-
ated waveform.
CONTROLS AND INDICATORS
16 15 14 13 12 11 10 9 8 7 6
18.
Figure 1. Model 4011 Controls and Indicators.
GATE LED. Indicates when the frequency counter display is second and when the 5 range is selected, the LED will flash every
updated. When the SOK through 5M ranges are selected, the LED 10 seconds. As the LED turns off, the display is updated.
will flash 10 times per second (every 0.1 seconds). When the 50 19. Hz and KHz LED. Indicates whether the counter is reading in Hz
through SK ranges are selected, the LED will flash once every or KHz.
OPERATING INSTRUCTIONS
The B+K PRECISION Model 4011 Function Generator is a versatile
instrument, capable of producing a variety of output waveforms over a
broad range of frequencies. To gain a working familiarity with the unit,
it is recommended that it be connected initially to an oscilloscope, so that
the effects of the various controls on the output waveforms can be
observed. Use this manual as required for reference until becoming
accustomed to the operating procedures.
FREQUENCY AND WAVEFORM SELECTION
1.
Initially, verify that the DUTY CYCLE (14), CMOS LEVEL (13),
DC OFFSET (12), —20dB (11), switches are in the OUT position
(released). This will produce a symmetrical waveform unaffected
by the other controls.
. Plug the unit into an appropriate power source and turn it on by
engaging the POWER switch (1).
. Select the desired waveform (SINE, SQUARE, or TRIANGLE) by
engaging one of the FUNCTION switches (3). Phase relationships
of the waveforms are shown in Fig. 2.
. Select the frequency of the waveform by engaging one of the RANGE
switches (2). The output frequency is displayed, along with the appropri-
ate measurement units, KHz or Hz (19), on the LED display.
. Rotate the COARSE (16) frequency control to quickly set the output
frequency to the approximate desired value. The FINE (15) fre-
quency control can then be used to easily set the output to the specific
desired value. The frequency selected is available at the OUTPUT
jack (6). In addition, a digital signal, either TTL or CMOS is
available at the TTL/CMOS jack (7) (refer to the “TTL/CMOS
OUTPUT” section of this manual).
Sine
Square OV =—---}--}-- —_——— | —
Triangle OV — »“”— — ^^ — FA — — т — „— — —
MTL оу — а Го —
wos ov 1-1
Figure 2. Output Waveform and Phase Relationship
6. Adjust the amplitude of the output as desired using the OUTPUT
LEVEL control (4). Rotation of this control varies the amplitude
from maximum to 20 db below maximum. An additional attenuation
of —20db is available by pushing in the —20dB switch (11). The
attenuation factors can be combined for a total of —40db. The
maximum signal level is 10 V p-p (into 50 52),
OPERATING INSTRUCTIONS
7. A superimposed DC component can be added to the output signal
by engaging the DC OFFSET switch (12) to enable operation of
the DC OFFSET control (5). Rotation of this control adds a positive
or negative DC component to the output signal. The DC component
introduced is independent of the OUTPUT LEVEL control and can
be varied by +10 volts open circuited or +5 volts into 50 Q. The DC
Offset does not affect the TTL/CMOS output jack. The effect of
DC OFFSET is shown in Fig. 3.
CONSIDERATIONS
1. Counterclockwise rotation of the COARSE frequency control de-
creases the output frequency to approximately one-tenth of the
maximum for the range selected (10:1). For example, if the 50 K
range is selected and the COARSE frequency control is set to full
counterclockwise, the output frequency is approximately 5 kHz.
2. It is advisable to set the FINE frequency control to the approximate
center of its rotation before setting the COARSE frequency control.
This assures that the FINE control will not reach its limit while
trying to finalize the frequency setting.
3. The FINE frequency control provides approximately +5% fre-
quency deviation from the COARSE control setting. This provides
vernier adjustment to easily set the frequency to a precise value.
4. When the 5 Hz range is selected, the gate time is 10 seconds and the
display is updated once every 10 seconds. The result of a frequency
change will not be displayed until 10 seconds later. Adjust the
frequency in progressively smaller steps, waiting for the display to
update until the desired frequency is obtained.
5. When outputing square waves or when using the TTL output,
terminate the cable into 50 Q to minimize ringing. Also, keep cables
as short as possible.
A. Zero DC Offset
With Maximum QV
Signal.
vy -- — — — — — — — —
+18 48 — — — — — — — — — — —
B. Offset Limits
Without Clipping. OY ———
SOV Positive Negative
DC Offset DC Offset
+10V -r—---————
C. Excessive Offset.
Ov — _ 00
—10V “Positive LS Negative
DC Offset DC Offset
Figure 3. Use of DC OFFSET Control
6. Remember that the output signal swing of the generator is limited
to +10 volts open circuited or +5 volts into 50 Q, and applies to the
combined peak-to-peak signal and DC offset. Clipping occurs
slightly above these levels. Fig. 3 illustrates the various operating
conditions encountered when using the DC offset. If the desired
output signal is large or if a large DC offset is required, an oscillo-
scope should be used to make sure that the desired signal is obtained
without undesirable clipping.
OPERATING INSTRUCTIONS
DUTY CYCLE CONTROL
The DUTY CYCLE control can be used to alter the symmetry of the
output waveform, to produce waveshapes such as those shown in Fig. 4.
For a square wave, symmetry variation amounts to changing the duty
cycle (ratio of “high” to “low” time), effectively converting the instru-
ment into a pulse generator. For a triangle wave, the result is a ramp, and
with a sine wave, a distorted waveshape called a slewed sine is produced.
The Model 4011 provides for symmetry variation from 15% to 85%.
I. Select the waveform desired either SINE, SQUARE or TRIANGLE.
2. Engage the DUTY CYCLE switch (14) and adjust the DUTY
CYCLE control (10) for the desired waveshape. Clockwise rotation
from center results in an increase in square wave duty cycle, and
changes the sine and triangle waves as shown in the top waveform
of each pair of Fig. 4. Counter-clockwise rotation results in the
bottom waveform in each pair.
3. Varying the duty cycle setting results in a slight change in frequency,
Adjust the COARSE and FINE frequency controls as required.
10
Pulse —_ a
(Square) __
Ramp И ——___/
ene | ~~
Slewed \_—— \
Sine
Figure 4. Effects of Symmetry Variation.
OPERATING INSTRUCTIONS
TTL/CMOS OUTPUT
The TTL/CMOS output jack provides a fast rise time square wave
output. Either a fixed TTL or a variable CMOS output level is available.
The output is positive with respect to ground and can be used as an
external sync pulse for oscilloscopes or as a variable frequency signal
source for exercising logic circuits. Because of the fast rise time of this
output, cable length should be minimized to limit ringing and overshoot.
1. Select the desired frequency range and adjust the frequency controls
as required. The OUTPUT LEVEL and DC OFFSET controls
have no effect on the signal at the TTL/CMOS jack.
2. When the CMOS LEVEL switch (13) is OFF, a TTL signal is
output at the TTL/CMOS jack. Select a CMOS signal by engaging
the CMOS LEVEL switch and adjust the level of the signal by
rotating the CMOS LEVEL control (8).
VOLTAGE CONTROLLED FREQUENCY OPERATION
The Model 4011 can be operated as a voltage-controlled generator by
using an external control voltage applied to the VCG INPUT jack. The
externally applied voltage will vary the frequency which is preselected
by the range switches and the frequency controls. Applying approxi-
mately +10 V with the COARSE control at full clockwise decreases the
output frequency by about 100 times (a 100:1 ratio).
1. Select the desired frequency range and waveform.
2. Set the starting frequency with the COARSE control. Apply a
positive DC voltage to the VCG INPUT input jack (9) to decrease
the frequency. A voltage from 0 to +10 V will cause the frequency
to decrease by a factor of 100 if the COARSE frequency control is
set at maximum CW rotation. For example, if the starting frequency
11
is 500 kHz, applying +10 V will change the output frequency to 5
kHz.
3. To operate the function generator as a sweep generator, apply a
positive going ramp signal to the VCG INPUT jack. As the ramp
voltage increases, the frequency decreases. The rate of sweep can
be adjusted by varying the frequency of the ramp signal.
4. Specific frequencies can be selected by applying a fixed dc voltage
to the VCG INPUT jack or the frequencies can be stepped by
applying a stepped dc voltage.
5. Do not apply more than +15 volts (dc or dc + ac peak) to the VCG
INPUT jack. Inputs of more than 15 volts will not cause any further
shift in the frequency and could cause damage to the generator.
OUTPUT PROTECTION CONSIDERATIONS
Use care when connecting the function generator output to a signal
injection point. Excessive voltage at the point of signal injection of the
function generator can causes internal damage. Under normal operation,
the generator output should never be connected to an external voltage
other than low dc values that can be matched with the DC OFFSET
control. The Model 4011 is overload protected so that shorting the output,
even continuously, will not cause damage. À fuse has been added in
series with the OUTPUT jack to help protect the instrument from
damage by connection to excessive external voltage.
Damage of this type usually occurs by accidentally connecting the
output of the function generator to a voltage in the equipment under test.
The following protective measures are strongly recommended:
1. The user should understand the equipment under test well enough
to identify valid signal injection points (ie: the base of a transistor,
OPERATING INSTRUCTIONS
a logic input of a gate, etc.). The voltage at valid signal injection
points is rarely high enough to damage the instrument.
2. If in doubt about the safety of a signal injection point, measure the
voltage present at the intended point of signal injection before
connecting the function generator output to that point.
3. When applying the main output of the function generator to a circuit
point containing a dc level, adjust the DC OFFSET control so that
the de level at the main output matches the circuit voltage.
4. Connect the TTL output only to TTL-level circuits. Connect the
CMOS output only to CMOS circuits. Measure the Vcc of the circuit
under test and adjust the CMOS LEVEL control as instructed in
the manual.
5. When the function generator is used by students or other inexperi-
enced users, the circuit of Fig. 5 could be added into your TTL output
probe or test clip set. It will protect the TTL output of the generator
against external voltages up to + 20 volts.
150 Q, 2 W
TTL (+) 2>——
FUNCTION GENERATOR TO
TTL OUTPUT CIRCUIT
=
GROUND
“uaa
- Poni
Figure 5. Circuit for Protection of TTL Output.
FUNCTION GENERATOR APPLICATIONS GUIDEBOOK
B+K Precision offers a “Guidebook to Function Generators” which
describes numerous applications for this instrument, including hook-up
details. It also includes a glossary of function generator terminology and
an explanation of function generator circuit operation. It may be obtained
free of charge by filling out and mailing the postage paid card enclosed
with the Model 4011.
MAINTENANCE
The following instructions are for use by
qualified service personnel only. To avoid
electrical shock, do not perform servicing
other than contained in the operating in-
structions unless you are qualified to do so.
Remember that ac line voltage is present on
line voltage input circuits any time the instru-
ment is plugged into an ac outlet, even if
turned off. Always unplug the function gen-
erator before performing service proce-
dures.
DISASSEMBLY AND REASSEMBLY
In order to access the fuses and the line voltage selector, the bottom
half of the case must be removed. Disassembly and reassembly proce-
dures are as follows:
Disassembly
|. Unplug the function generator and turn the unit upside down.
2. Remove the four screws from the bottom of the case.
3. Lift otf the bottom cover.
Reassembly
|. Line up the slots in the bottom case half with the front panel and the
back panel.
2. Carefully push the bottom half down onto the top half.
3. Replace the four screws. |
FUSE REPLACEMENT
|. To replace a fuse. disassemble the case as described above.
2. To replace the line fuse, locate the fuse holder. It is located at the
rear of the circuit board, to the right of the power transformer. The
fuse should not normally open unless a problem has developed with
the unit. Try to determine and correct the cause of the blown fuse,
then repiace only with the correct value fuse (refer to fuse label near
fuse hoider).
3. To replace the Output fuse. locate the fuse holder. It is located on
the output amplifier PC board mounted to the front panel. Replace
only with the correct value fuse 0.2 A siow blow fuse,
4. Reassemble case as described above.
LINE VOLTAGE SELECTION
|. Disassemble the case as described above.
2. Locate the line voltage selection connector. It is located on the PC
board behind the power transformer.
MAINTENANCE
fo
Un
Unplug the connector by pulling straight up.
Push the connector onto the desired voltage selection pin. Be sure
that the correct fuse is installed in the fuse holder (refer to label near
fuse helder).
Reassemble case as described above.
14
INSTRUMENT REPAIR SERVICE
Because of the specialized skills and test equipment required for
instrument repair and calibration, many customers prefer to rely upon
B+K PRECISION for this service. We maintain a network of
B+K PRECISION authorized service agencies for this purpose. To use
this service, even if the instrument is no longer under warranty, follow
the instructions given in the WARRANTY SERVICE INSTRUCTIONS
portion of this manual. There 1s a nominal charge for instruments out of
warranty.
TEST INSTRUMENT SAFETY
(continued from inside front cover)
6. Some equipment with a two-wire ac power cord, including some with polarized power plugs, is the “hot chassis” type. This includes most recent
television receivers and audio equipment. A plastic or wooden cabinet insulates the chassis to protect the customer. When the cabinet is removed
for servicing, a serious shock hazard exists if the chassis is touched. Not only does this present a dangerous shock hazard, but damage to test
instruments or the equipment under test may result from connecting the ground lead of most test instruments to a “hot chassis”. To test “hot chassis”
equipment, always connect an isolation transformer between the ac outlet and the equipment under test. The B+K Precision Model TR-110 or
1604 Isolation Transformer, or Model 1653 or 1655 AC Power Supply is suitable fof most applications. To be on the safe side, treat all two-wire
ac equipment as “hot-chassis” unless you are sure it has an isolated chassis or an earth ground chassis.
7. On test instruments or any equipment with a 3-wire ac power plug, use only a 3-wire outlet. This is a safety feature to keep the housing or other
exposed elements at earth ground.
8. Never work alone. Someone should be nearby to render aid if necessary. Training in CPR (cardio-pulmonary resuscitation) first aid is highly
recommended.