Welch Allyn Solarc M21P021 Technical Operation Manual

TECHNICAL OPERATION GUIDE
Focused Innovation.
LIGHTING
PRODUCTS
DIVISION
TABLE OF CONTENTS
Introduction ............................................................................................................................3
Sōlarc Lamp Overview .........................................................................................................4
Sōlarc Lamp Advantages.....................................................................................................4
Sōlarc Lamp Operating Characteristics............................................................................5
Sōlarc Lamp Safety, Handling and Disposal ....................................................................5
Lamp Life & Maintenance ...................................................................................................6
Designing Sōlarc Lamps into Your Products....................................................................7
Lamp Temperature & Cooling .............................................................................................9
Optical Performance Optimization ...................................................................................10
Lamp Replacement Instructions (LE, LM, LB Models) .................................................11
Troubleshooting ...................................................................................................................11
Warranty ...............................................................................................................................11
Conclusion ............................................................................................................................11
Today’s markets dictate that the products you design
must meet your customers’ needs as well as stand out
from their competition. You’re asked to deliver brighter,
longer-lasting illumination in a smaller, more portable
product. Put another way, your customers want the
power of the sun in the palm of their hands.
With Welch Allyn’s Sōlarc lamps, that’s precisely
what they get. Sōlarc lamps, Light Engines and Light
Modules are used worldwide to supply high-quality,
white light in a wide variety of optical illumination
systems. This is because Sōlarc products give you the
design flexibility for use in a wide variety of applications.
When properly applied, they will reliably provide
hundreds of hours of excellent product performance.
And, with their simple packaging, they can be
designed into your products with ease.
As with any new technology, it is important that you
understand key application techniques. This Sōlarc
Technical Operation Guide has been arranged to help
you easily find the information you need for your
specific application. It summarizes the important
information and assembly hints that will help get
you started. For more detailed information on specific
Sōlarc lamp solutions, please contact your Welch Allyn
representative.
By following the guidelines given in this guide, you
(and your customers) will be rewarded with years of
dependable, trouble-free service from your new Sōlarc
products. Please read these instructions thoroughly
before use.
Sōlarc®—The brilliant component
for successful products.
3
Sōlarc LAMP OVERVIEW
Each Sōlarc lamp is a metal halide light source in the class
of high-pressure, high-intensity-discharge (HID) lights,
which differ from halogen, incandescent, fluorescent or
light emitting diode (LED) illumination sources. Light is
emitted from an arc discharge between two closely spaced
electrodes, which are hermetically sealed inside a small
quartz glass envelope. During operation, small amounts of
metals are heated to a liquid state that provide the needed
vapors to create the desired light color.
Precision Focus
The light emitted from this arc tube is intense. Appropriate
safety precautions relating to exposure protection are
required. Metal halide lamps operate at very high
temperatures and pressures so proper mounting, cooling
and ventilation are required to assure reliable operation.
While highly efficient, these metal halide lamps are
sensitive to thermal fluctuations and orientation effects.
Expect larger variations in color and output than other
lower efficiency technologies.
Because they offer low-power arc lamp operation, Sōlarc
lamps allow you to design smaller, lightweight and portable
products. For example, a 21 W Sōlarc lamp with elliptical
reflector weighs just 24 g. To further facilitate portability,
the lamp’s ballast, measuring 5.1 x 5.8 x 1.1 cm, weighs
just 60 g. In addition, Sōlarc’s low power draw (10, 18,
21, 24 or 50 W) makes battery operation possible, thus
enhancing your product’s value to your customers.
Sōlarc lamps have unique operating and handling
characteristics that should be understood to achieve
successful and reliable operation:
• Sōlarc’s quartz glass must be kept clean
• The glass lamps should be handled with care, giving special
attention to the quartz arc tube
• Metal halide lamps use high-voltage, short-duration pulses
to initiate operation
• Sōlarc is a direct current (DC) lamp, and proper electrical wiring
polarity must be observed to prevent damage to the lamp
Sōlarc LAMP ADVANTAGES
Brilliant Illumination
Thanks to Welch Allyn’s patented design, the Sōlarc
miniature arc lamp provides pure, white illumination
with a high color temperature. Sōlarc inherently provides
solar-quality brightness, true color rendition and true color
balance, ensuring unparalleled results for virtually any
lighting product application.
Low Power Draw
Sōlarc lamps operate at 60+ lumens/watt. This allows your
product to produce three times the amount of light compared
to a halogen lamp running at the same power level. With a
standard selection of outputs of 10, 18, 21, 24 and 50 W,
Sōlarc allows you to design products that are more
compact, flexible, reliable and efficient.
4
Sōlarc lamps feature a small, typically 1.2 mm, arc gap,
the smallest gap available in a metal halide arc lamp.
Combined with elliptical reflectors, this arc gap allows
you to focus illumination with laser-like precision into
very small areas, such as projection display panels or
fiber optic cables.
Portability
Shock Resistance
Sōlarc’s arc lamp generates its brilliant illumination with
precisely aligned electrodes in place of a tungsten filament.
This design enhances Sōlarc’s durability against shock
or vibration, making it an ideal lamp for products that
demand superior illumination in rugged operating
environments.
Consistent Light Output
Sōlarc’s superior quality light output will typically maintain
at least 75% of its initial value throughout its life. This
means that both your reputation and your customers’
products will benefit from reliable, consistent performance
over longer periods of time.
Easier to Use
High-efficiency operation—combined with its lower gas
volume and miniature size—mean that Sōlarc lamps
provide solar-quality light output, yet require 1/3 less
power than halogen lamps. Additionally, Sōlarc lamps’
low wattage generates less heat that halogen lamps. This
feature allows you to design products requiring less
complex thermal management systems. The net result
of these features is that you can design products that
deliver optimum performance and safety at a lower
manufacturing cost.
Welch Allyn Quality
Every Welch Allyn Sōlarc lamp is designed and
manufactured within our strict production standards
and tight tolerances to ensure that each operates to its
exact specifications. By demanding precise performance
from our lamps and our manufacturing processes, we
will ensure the value of your products.
Sōlarc
LAMP OPERATING CHARACTERISTICS
Appearance
Sōlarc lamps contain small amounts of metals. These metals
are in both liquid and solid forms when the lamp is cold.
When cold, these metals may appear to be dark reddish
or reddish-brown in color, can appear as spots or even
a film on the inside surface of the arc tube chamber. This
appearance is normal and, as the lamp warms up, the
metals evaporate and do not interfere with the proper
operation of the lamp.
Warm-up
Sōlarc lamps take a brief time to come up to full power
after they are turned on (the general rule being about 1
second per watt). For example, a 20 W lamp will take
about 20 seconds to come to normal brightness. Some
amount of instability, i.e., flickering or flashing, is normal
during warm-up and will diminish after the lamp reaches
its thermal equilibrium.
Restart
Output Ratings
The industry standard for measuring output of light is the
lumen. Lumen is a measure of the visible light related to
the sensitivity of the human eye. Sōlarc lamps are generally
designed, built, and characterized using the lumen as the
measure of output and using maintained lumens as the
measure of output over time. Because Sōlarc lamps produce
full-color light across the entire visible spectrum (UV to
IR), they are often chosen for their unique blue (UV curing)
or red (IR detection) output. Check specifications carefully
to be sure that the lamp is controlled for the light
characteristics you are designing in.
Output Stability
Light output fluctuations are a normal characteristic of
discharge lights. Generally, fluctuations are not objectionable
if they vary no more than 5% at any given time. Sōlarc
lamps are controlled to have no more than 5% fluctuations
in initial output. Metal halide lamps can also exhibit
occasional flaring, or bright flashes of red or pinkish light.
Flaring occurs as the liquid metals settle into a stable
thermal location within the bulb chamber. Flaring generally
occurs during initial warm-up, if the lamp is jarred, or if it
changes orientation.
If power is interrupted to an operating lamp, the pressure
inside the chamber is still very high and the starting pulses
will not be strong enough to form an arc between the
electrodes. The lamp must cool to a point where an arc
can be started. The time required to cool follows our
general rule of about 1 second per watt. (A 10 W lamp
will require about 10 seconds to cool down prior
to restarting.)
LAMP SAFETY, HANDLING & DISPOSAL
Ballast Compatibility
Safety
A ballast is the electronic control circuit required to operate
a discharge lamp. Sōlarc lamps are direct current (DC)
metal halide arc lamps. As such, they are to be operated
with only approved electronic ballasts. In order to start
the lamp, an arc must be struck across the gap formed by
the electrodes. To do this, the ballast generates a series of
very high voltage (~10 kV) and very short (<1 microsecond)
pulses to start the lamp. They can often be heard and
sound like a series of clicks. Again, Sōlarc lamps are DC
operated and there is a distinct polarity associated with
proper electrical connection. Improper wiring can cause
either lamp or ballast failure.
Operating Orientation
Sōlarc’s arc is a glowing, heated ball of vapor. Because
heat rises relative to the force of gravity, high-intensity
discharge lamps are sensitive to orientation. Sōlarc lamps
are designed to be operated in one orientation, usually
horizontal unless otherwise specified. Orienting the lamp
contrary to its original design will cause the thermal
environment to change, thus increasing output variability
and possibly reducing life.
As with any high-power lighting system, it’s important to
remember specific safety issues. The Sōlarc lamp system
generates a series of high-voltage ignition pulses of
approximately 6 – 10 kV for a short time during each
starting cycle. If a lamp fails to start, those starting pulses
will stop after 2 seconds. Do not switch the light source
from ON to OFF in rapid succession, as this will dramatically
shorten lamp life. We also recommend that each application
be fused in order to protect the product against any
internal failures.
Always allow lamp to cool before replacing. Do not
remove the lamp from equipment until it has cooled
completely. For optimum performance, avoid handling the
bulb or the reflector. Fingerprints or other contaminants
on the glass may result in performance degradation.
5
LAMP SAFETY, HANDLING & DISPOSAL cont’d
LAMP LIFE & MAINTENANCE
Photobiological Safety Compliance Standard RP-27.3
The industry standard for reporting lamp life is median
hours—the point at which 50% of the lamps have stopped
operating satisfactorily. Generally, a lamp is considered to
have failed if it no longer starts or the lumen output has
fallen to half of its initial value. Welch Allyn defines a
rated “median life” for all its lamps. This is a statistical
determination—based on periodic testing—of the median
operating time for randomly selected groups of lamps.
One half of the lamps will continue to operate beyond this
median life while others will reach their end-of-life earlier.
As with any Sōlarc product, UV precautions must be
taken when directly handling the lamp. Ultraviolet, visible
and infrared radiation are emitted from metal halide lamps.
Possible skin or eye irritation can result from exposure to
the output of a 21 W Sōlarc lamp exceeding 15 minutes in
one day. Use appropriate personal protective equipment.
Do not stare at an exposed lamp in operation. Due to the
extremely high brightness of the lamp, proper attenuating
glasses must be worn when directly viewing the bulb.
During operation, the lamp should be enclosed in a
housing to prevent injury in the circumstance of the
lamp shattering.
Handling
Ballast products are electrostatic sensitive electronic assemblies
and should be handled as such. Proper electrostatic discharge
(ESD) handling procedures must be employed.
Protect the quartz arc tube when handling the lamp.
The arc tube may be protruding from the end of some
reflectorized lamp assemblies. Keep the arc lamp clean.
Do not touch the quartz tube, the inside surface of the
reflector, or the connecting wires. Contamination can
degrade lamp performance or cause premature failures.
If necessary, clean the lamp by wiping with a lint-free
towel or cotton swab immersed in denatured alcohol.
The high-intensity light at the front of the light source and
possibly at the tip of the fiber optic bundle, if used, may
give rise to bright light and high temperatures. To minimize
the risk of injury, avoid direct viewing or contact.
Disposal
Sōlarc lamps contain a small amount of mercury—usually
no more than found in typical fluorescent lighting.
Disposal and handling must conform to local regulations
and hazardous waste disposal guidelines.
Do not remove lamp from equipment until it has cooled.
Never handle the lamp when it is operating!
The predominate symptom of end-of-life is the inability to
start the lamp. Once a lamp has started, one can generally
count on that lamp continuing to operate throughout a
given procedure, however there is a possibility that the
lamp could rupture. For that reason, lamps should be
installed in an enclosure.
To fully characterize lamp life, one must also define a
duty cycle. Duty cycle is how often a lamp is turned on
and off. Sōlarc lamps are typically tested in the laboratory
with a duty cycle of one or two hours on and 15 or 30
minutes off. More frequent cycling will reduce the lamp
life. For instance, turning the lamp off every 10 minutes
may reduce rated life as much as 50%. Conversely,
operating the lamp in a continuous mode may extend
life up to 30%.
Lamp life will also be decreased if the lamp is operated
above designed operating temperatures. (Please refer to
Lamp Temperature & Cooling on page 9.) It is important
that the equipment designer ensures that the maximum
operating temperature is not exceeded and that free airflow
is available at all times.
Figure 9 (page 14) depicts a graph of lumen maintenance
versus life for the 21 W lamp. This data was taken with
the lamps operating in their standard duty cycles at
rated wattage. Performance can vary substantially under
different operating conditions. You should always qualify
performance for the specific operation that you design.
In Figures 10–13 (starting on page 14), you will find
graphs indicating the color stability of the lamp. The first
pair of plots indicates X and Y chromaticity deviation
versus life, while the second set of plots show a spectral
distribution taken from a typical lamp when new and after
a period of time. Sōlarc lamps will maintain a high level
of both chromaticity and light intensity throughout
their lives.
6
DESIGNING Sōlarc LAMPS INTO
YOUR PRODUCTS
Packaging
Electromagnetic Interference (EMI)
When developing mountings and enclosures for Sōlarc
lamps and ballasts there are several design aspects
to consider.
The Sōlarc product family has been designed to pass
industry-standard EMI requirements. The ballast should be
located close to the lamp for this very reason. It may be
necessary to add an additional metal shield over both the
lamp and ballast depending on the specified EMI immunity
levels. In addition, it is best to keep the distance from the
power source to the ballast as short as possible. When
specifying long wire lengths it is best to use twisted pair
configuration and/or shielded wire to minimize radiated
EMI from that wire.
Heat management is critical. In many applications
forced-air cooling is used to maintain the recommended
temperatures at the critical measurement points. For
Sōlarc lamps with no cover glass, drawing the air across
the face of the lamp is preferable—blowing air on the
lamp is not recommended. Use the natural effect of heat
rising as a supplement to drawing the air up from the
bottom of the lamp. This is how all devices manufactured
by Welch Allyn are designed. If the system cannot be
cooled using forced-air cooling, such as in a flashlight or
torch, sufficient thermal conduction methods must be used
to assure critical thermal points are within specification.
When designing light engine and light module components
which incorporate vents and cooling fans, be careful to
assure sufficient clearance and pathways so that the airflow
is not obstructed.
While Sōlarc lamps have no filament to break, they are
nonetheless made of quartz glass and subject to breakage
from shock and vibration. Shock mounting techniques and
shock isolation can provide a more robust design.
Remember it is up to you, the OEM, to test the end
product in its intended use to assure it meets your
customer’s requirement.
Mounting
Sōlarc arc lamps are specified for operation in a specific
orientation, such as horizontal or vertical base down.
Verify specified orientation with the appropriate lamp
specification sheet. Lamps specified for horizontal
operation have a preferred rotational orientation. Refer to
the specific lamp data sheet or follow the “THIS SIDE UP”
or “UP” designation on the lamp base. To prevent damage
during lamp installation, mounting and replacing, care
must be taken to avoid mechanical interference with the
quartz arc tube.
Mount the printed circuit board version of the ballast as
desired by using the four corner through-holes provided
on the circuit board assembly or by some other acceptable
means. Exercise care when handling and mounting the
circuit board assembly to prevent mechanical stressing of
the ballast components. It is not recommended to use the
ballast heat sink for mounting, as it is electrically floating.
Since there is high voltage on the board, spacing of
9.53 mm (0.375 in) on all sides of the ballast is required,
or appropriate nonconductive electrical insulating
material must be used.
System Integration Guidelines to Minimize EMI
Ballasts and other power conversion circuitry emit parasitic
energy that may affect or interfere with the operation of
other equipment. The following guidelines are recommended
to minimize ballast emissions and reduce the possibility of
radiated or conducted interference with other equipment.
• Overlapping sections of the ballast/electronic enclosure should
be clean and free from paint
• Use metal screws to fasten cabinet sections together
• Attempt to keep fasteners approximately two inches apart
and avoid any distortion of the clean metal mating surfaces.
Use EMI gasketing if distortion is unavoidable
• Avoid dissimilar shielding metals and moisture that will cause
galvanic action and thus cause deterioration of the clean
metal shielding surfaces
• Maximum shielding occurs with materials that have the
highest conductivity
• Principal EMI issues arise due to breaches in shielding
• Cover or subdivide areas inside large electronic enclosures
• Avoid long ground wire connections to reduce loop size
• Route all internal cables as close to the ground plane/surfaces
as possible to minimize loop size
• Use an IEC power input filter module
• Mount an IEC power input filter module to a clean, paint-free
section of the cabinet wall and as close as possible to the DC
power supply. Use the widest and shortest possible strap to
ground the input filter module to the ground plane if unable to
ground the filter module directly to cabinet wall
• Plastic-coated enclosures provide excellent HF shielding but
considerable care is needed to ensure that all seams are
conductively closed
• Do not route cables close to seams or openings and especially
not close to small openings or cracks
• Terminate all cable shields to the enclosure
7
System Integration Guidelines to Minimize
EMI cont’d
• Use holes and avoid the use of slots for cooling openings
• Use chokes on power leads and or twist power leads to
eliminate noise issues
• Make sure all power terminals are clean and tight
• Do not run wires parallel to each other, which could cause
crosstalk issues
assembly shown in Figures 1 & 2, location J101. Pin 1
is the positive input voltage and Pin 2 is the negative
input voltage. Slide the connector housing portion of the
assembly onto the input power connector, location J101,
until the mating halves lock in place. Observe the wiring
voltage polarity as specified in the pinouts section in the
performance specifications table. Failure to observe input
power wiring polarity could result in failure of the product.
Wiring for Printed Circuit Board (PC) Version Ballast
• Avoid tying or locating signal leads (DC) close to power leads (AC)
• Keep ballast module approximately two feet away from a
CRT, computer or other magnetic field-sensitive devices.
Use thicker shielding if close proximity is unavoidable
Figures 1 & 2: Ballast Assemblies
• Ferrite cores can normally be used to eliminate a resonance
problem or control interference
System Integration Hints
Physically locate the ballast away from circuitry that is
noise sensitive or circuitry that is routed outside of the
system housing. This will help control EMI/RFI emissions
and help enable the ballast to be compatible with the system.
Don’t bundle sensitive signal leads with the ballast input
and output power leads. Intentional spacing or shielding
may be required to enable the ballast to be compatible
with adjacent circuitry. A common symptom is interference
with adjacent circuits during ignition.
Operating Voltage
18, 21 & 24 W Ballast
Maintaining the proper input voltage is extremely important.
Do not exceed the absolute maximum voltage listed for
your particular ballast. It may cause a nonrecoverable
failure of the lamp, ballast or both.
When operating with batteries, it’s important to research
the batteries’ characteristics when fully charged and how
they discharge to ensure compatibility with your ballast.
If a lamp fails to start, the ballast will shut down and will
only draw a low amount of power. The power must be
cycled off and back on in order to re-light the lamp.
Input Power Supply Selection
The power ratings of the ballasts refer to the output
power to the lamp. The ballast input power will always
be greater than its output power because of its efficiency
limitations. The ballast has a capacitive input, which will
demand a short-duration inrush current from the power
supply. This is usually not a cause for concern.
Input Wiring for Printed Circuit Board (PC)
Version Ballast
Welch Allyn recommends complying with IPC-A610D
solder process standard or equivalent. Construct an input
power connector assembly compatible with the input
connector (Molex 41791 connector 2-pin series or equivalent)
located on the ballast circuit board assembly. The input
connector can be found at the bottom edge of the ballast
8
50 W Ballast
All measurements are mm [in.]
Welch Allyn arc lamps are designed for direct current
(DC) operation. It is vital that the lamp be installed and
maintained with the correct polarity. The supplied polarized
connectors, which electrically couple the arc lamp and
ballast, are designed to provide the proper voltage polarity.
The two insulated wires supplied with the connection
assemblies are colored-coded: the black wire is connected
to the cathode and the white wire is connected to the
anode of the arc lamp. Solder the anode lead (white wire)
of the lamp connector assembly to P1. Solder the cathode
lead (black wire) of the lamp connector assembly to P2.
Trim any excess material. The P1 and P2 output terminals
can be found at the top middle edge of the ballast
assemblies shown in Figures 1 and 2.
• Avoid connecting the P1 and P2 terminals to anything other
than the arc lamp. Instrumentation and/or other circuitry
connected to either one of these electrical nodes can drastically
affect normal ballast operating performance
• High-voltage pulses are present on the P1 terminal during ignition
• Failure to observe input power wiring polarity could result in
catastrophic failure of the product
Labeling
Proper labeling is important with any product, and the
Sōlarc is no exception. Warnings reminding users that the
lamps can be hot and should be allowed to cool down
prior to replacement, and not to put anything, including
fingers, into the lamp socket, should be clearly marked in
the appropriate languages.
LAMP TEMPERATURE & COOLING
Cooling (10 W Systems)
Heat removal is important. The main heat transfer occurs
through the ballast. The ballast sides also provide the best
mechanical surface for heat conduction to occur. Although
plastic housings can be designed into your product, it is
best to have a solid metal-to-metal contact with the ballast
can. An air gap between the ballast and its mounting
surface should be avoided. If plastic is preferred, then
heat-transferring plastics such as 30% carbon-filled or
glass-filled material are best.
The most important measurement of a proper Sōlarc lamp
and ballast installation is the temperature on the ballast
metal can. With a thermocouple attached half way up the
side of the ballast, you can measure the heat conduction
of the system. It’s important to keep the maximum case
temperature no greater than 90˚C.
Unusual increases in operating temperature can be caused
by a variety of factors:
• Nothing should be mounted directly to the back side of
the reflector
• An additional heat shield (commonly found on halogen
installations) will cause a significant rise in operating
temperatures within the assembly
• Any housing that immediately surrounds the lamp should be
black so as not to reflect stray light back into the lamp
• When an additional cover glass is used, make sure it is rated
for high transmission; otherwise reflected light energy from
the front can overheat the system
• Never use any plastic material as an outside barrier
• The common cause of high temperature is overvoltage
to the ballast. Make sure that you have the correct ballast for
the particular battery type and configuration
When designing the enclosure, consider the fact that
your product may not always be running in an ideal
laboratory environment. The 90˚C maximum temperature
should take into account typical operating temperatures
the product will experience in actual use, as well as any
extreme conditions it might encounter.
Cooling (18 W – 60 W Systems)
The maintenance of adequate cooling is another critical
consideration in lamp life and arc stability. The lamp must
not exceed its operating temperature limits, which in most
cases requires that the lamp be forced air-cooled. Cooling
must be sufficient to maintain the temperature at the tip
of the arc tube generally between 200˚C and 285˚C.
In a few situations it may be possible to cool the lamp by
convection. In general however, the equipment designer
must be certain that the flow of air is adequate and cannot
be blocked. Conversely, it’s also important that the lamp
not operate overly cooled or it will experience instability,
inconsistent performance, an arc that is bluer in color and
may cause possible flickering.
The critical temperatures are at the seals of the arc tube
and at the molybdenum foils. If the temperature limits
at these points are exceeded, the seal between the foils
and the glass envelope may fail and create a leak, thus
shortening lamp life and causing erratic performance.
9
Cooling (18 W – 60 W Systems) cont’d
It is equally important not to directly cool the arc chamber
(the center of the bulb). This may also cause erratic
performance and shortened life.
Figures 14 and 15 show the critical regions of the lamp
and the optimum temperature ranges. To help you design
the Sōlarc lamp into your equipment, Welch Allyn can
provide specially prepared lamps with Type K thermocouples
attached to the exposed end of the arc tube (anode seal)
and embedded at the cathode seal. Using these sensors,
thermal management systems and operating temperatures
can be monitored and optimized.
While the operating temperature at both ends of the
tube is important, the thermal characteristics of the lamp
construction actually make the exposed end of the arc
tube the most vulnerable. The reflector tends to conduct
heat away from the near end. For this reason, it is wise
to carefully distribute the airflow to the lamp.
Some air must be directed across the reflector in order to
prevent adverse effects. The designer must also allocate
some airflow across the bulb tip without directly cooling
the arc chamber itself. This may require careful design
since the reference surface for the lamp is the front face of
the reflector. Drawing air across the front of the reflector
and directly cooling the tip of the arc tube and anode seal
can accomplish this. (Refer to Figure 3.) Sōlarc lamps
have been incorporated in Welch Allyn proprietary products
using forced-air cooling at flows ranging from 9 to 20 cfm
(ft3/min) (0.25 to 0.57 m3/min), depending on external
environment and chassis restrictions.
Figure 3: Lamp Cooling
Many of the same considerations apply to a single-ended
lamp, except that the application may be complicated
by the user’s own optical design.
The ballast should reside in a well ventilated housing.
Forced-air cooling is highly recommended, but not a strict
requirement. The power field effect transistor (FET) heat
sink (largest heat sink on PC board) located adjacent to
the input power connections must be maintained below
90˚C. See Figures 1 and 2 for the power FET location.
For optimum temperature measurement, position and
adhere a thermocouple on the reverse side of the FET
heat sink at the same height as the FET. Increase airflow
requirements by 1 cfm for every 2˚C rise above 25˚C.
Do not allow the temperature of the heat sink to rise
above 125˚C. Additional heat sinking is possible by
screwing more thermally conducting material to the top
of the heat sink. Use a #2 screw and thermal compound
to ensure proper conduction.
OPTICAL PERFORMANCE OPTIMIZATION
Sōlarc lamps are typically mounted within dichroiccoated reflectors for visible applications. For fiber optic
illumination, typical elliptical reflectors are utilized where
the arc is positioned at the internal reflector focal point
(F1) and light emitted from the lamp is reflected and
redirected to the external focal point (F2). The majority
of reflected light is focused at the F2 position within a
defined solid angle. The angular distribution of the light
emitted from the reflector is a function of the ellipse
geometry and the radiation emitted from the arc source.
For maximum transmission through fiber optics, it is
critical to match the reflector angular distribution to the
fiber optic acceptance cone angle (otherwise known as
numerical aperture—NA). The NA of the lamp must
match the NA of the fiber for optimal performance.
The angular distribution of the lamp coupled with larger
bundle diameters can impact the optical performance. A
light depression is typically observed when the angular
distribution propagates through the fiber optics. In most
applications, it is desirable to tilt the lamp’s optical axis
relative to the fiber optic opto-mechanical axis to eliminate
this propagated depression for uniform projected
illumination as viewed from the fiber optic distal end.
Welch Allyn typically sets this angle at about 12 degrees.
This tilting of the lamp can also be used to provide
additional thermal optimization. Tilting the lamp’s
connector downward allows the reflector’s top to
open slightly, allowing the chimney effect to exhaust
more efficiently.
10
LAMP REPLACEMENT INSTRUCTIONS
(LE, LM, LB MODELS)
1. Turn unit off and unplug the power from the light engine
Maintenance and Repair (LE)
2. Rotate lamp spring retainer from lamp spring
Only qualified personnel should make electrical inspections
and repair Welch Allyn Sōlarc light engines, light modules
and light boxes.
3. Disconnect the lamp connector and remove the lamp by pulling
back and up against the lamp spring
4. Replace with Welch Allyn replacement lamp only
5. Reconnect the lamp to the connector and insert lamp so that
the lamp is seated properly in the lamp block; pay attention to
applicable keys or alignment pins
6. Rotate lamp spring retainer back into position over lamp spring
For additional troubleshooting or repair information,
contact Welch Allyn at 315.685.4347.
WARRANTY
Refer to Welch Allyn Lighting Product’s standard terms
and conditions of sale for warranty information.
TROUBLESHOOTING
Discharge lamps fail for a variety of causes that all relate
to thermal and mechanical stresses imposed by the extreme
operating temperatures inside the lamp. Typical failure
modes include chamber rupture (sometimes with an
audible pop), cracking and leaks of chamber, and cracking
and leaks of or near the glass-to-metal seals. These types
of failure modes are normal and do not imply a
defective lamp.
If the lamp fails to ignite:
• Check input and output wiring polarity and integrity
• Attempt ignition a second time after properly resetting the
ballast by disconnecting and reconnecting the input voltage
• Verify proper input power—both voltage and current
If the above steps fail to correct the problem:
• Ensure the anode wire is not routed near any metal or
other conductor
• Ensure that no arcing occurs on the ballast assembly in the
area near the P1 connector. (A dark room enables visual
detection of arcing)
• Ensure that no arcing occurs between the ballast assembly and
any adjacent subassembly within the system (components,
subassemblies, wire harnesses, etc.). A 9.53 mm (0.375") air
spacing (or higher dielectric strength) is recommended in the
above mentioned areas
CONCLUSION
For over 80 years, Welch Allyn has pioneered the
development of precision lighting systems in medical
diagnostic instruments. And throughout this time, the
hallmark of every Welch Allyn miniature lighting system
has been quality. Using several proprietary manufacturing
processes, our design engineers ensure that each Welch
Allyn lamp will operate in conformity with its quoted
specifications. This commitment to product quality and
performance was confirmed again in 1996 when Welch
Allyn’s Lighting Products division was certified for
ISO 13485.
Welch Allyn’s Sōlarc lamps combine all the features you’re
looking for in a lamp: solar-quality illumination, low
power consumption, precision focus, safety and multiple
wattage configurations. All this—along with Welch Allyn’s
assurance that each and every Sōlarc lamp will operate to
specifications—combines to deliver lamps that ensure your
product’s success.
To take full advantage of the design possibilities that
Sōlarc can deliver, feel free to draw from our experience
in designing products using Sōlarc lamps by contacting us.
If you would like further guidance and/or information on
any of the design issues found in this manual—or for
information on our complete line of miniature Halogen
HPX™ lamps—contact a Welch Allyn representative today
at 315.685.4347.
Thank you.
Lamp Stability
Unstable lamp operation accompanied by a markedly
bluish cast to the light may indicate an overcooled lamp.
Verify proper power input and operation of the thermal
control circuit.
Early lamp failure accompanied by a markedly reddish
cast to the light may indicate a lamp that is overheated.
Verify proper power input and operation of the thermal
control circuit. Verify that no obstructions exist in the
airflow path.
11
Figure 4: Ballast / Arc Lamp Configuration
All measurements are mm [in.]
Figure 5: Ballast / Arc Lamp Configuration
All measurements are mm [in.]
12
Figure 6: Parabolic Reflectorized Lamps Typical Performance Specifications
LAMP P/N
M21P011
M21P021
14,500
5,000
12
20
6,000
6,000
Output Performance
Output (CBCP)
Beam Divergence (@ 50% Intensity)
Application Information
Color Temperature (˚K)
Chromaticity (x,y)
0.32, 0.32
0.32, 0.32
Median Life (Hours)
750
750
Warm-up Time To 90% Output (Seconds)
20
20
Restart Time To 90% Output (Seconds)
25
Ballast
25
B22R001
Input Voltage
Current @ 12 VDC
Lamp Connector
9.8 V–15 V
9.8 V–15 V
2.3 A
2.3 A
C18A003
Duty cycle for Rated Median Lamp Life: 21 W—1 hr on / 15 min off. 50 W—2 hr on / 15 min off
Figure 7: 19, 22 & 25 Watt Ballasts Performance Specifications
ELECTRICAL
B19R001
B22R001
B25R001
Specifications, unless otherwise indicated, are nominal at or near 25˚C.
Input Power
Turn-on Voltage1
9.8 VDC
Turn-off Voltage1
9.2 VDC
Maximum Voltage
16.0 VDC
Steady State Current2
2.0 A
2.3 A
2.6 A
ENVIRONMENTAL
0˚ to +70˚C
(forced convection cooling recommended)
Operating Temperature
Storage Temperature
PINOUTS
CONNECTOR
Input Power
(Molex 41791 series)
J101 41671 or
26-48-1025
Pin 1 = “+” input power
Pin 2 = “-” input power
P1
P2
Anode, white wire on ballast connector
Cathode, black wire on ballast connector
Output Power
1
2
-40 to +105˚C
Turn-on and turn-off specifications are a function of input wiring resistance. The voltage at the pins of J101 are regulated using
the remote sense leads of a power supply.
Steady state current flow after lamp warm-up @ 12 V.
13
Figure 8: Sōlarc® MR11 Elliptical Lamp Typical Performance Specifications
Wattage
19 Watts
22 Watts
25 Watts
Lumens Through a 4 mm Aperture
560
620
720
Lumens Through a 2 mm Aperture
200
260
350
Correlated Color Temperature (˚K)
6,900
6,200
5,200
Chromaticity (CIX, CIY)
0.32, 0.31
0.33, 0.32
0.33, 0.34
Lamp Life (Hours)
1,100
750
350
Performance @ Rated Power: Luminous Flux
Lamp Maintenance and Spectrum
Refer to Figures 9–13
Warm-up Time to 90% Output
20 Seconds
Restart Time to 90% Output
30 Seconds
Reflectorized Lamp Application Information
MR11
Numerical Aperture
NA–0.67
Spot Size @ Focal Plane F2
2 mm @ 50% Intensity
F2 Distance from Rim
14.7 mm
Figure 9: 21 W Typical Light Maintenance
14
Figure 11: CIY Chromaticity
Percent Deviation (%)
Percent Deviation (%)
Figure 10: CIX Chromaticity Maintenance
Figure 12: Spectral Output at Zero Hours
Figure 13: Spectral Output at 650 Hours
Spectral Distribution
The plots above provide an indication of the degree of relative energy changes within the spectral distribution as the lamp
ages. The curves describe the performance of a typical 21 W lamp in its reflector, operated at rated wattage and standard
duty cycle.
Figure 14: 18, 21 & 24 W Reflectorized & Sel Lamps
Figure 15: 50 W Reflectorized Lamp
15
Welch Allyn—Your Source For
Precision Arc & Halogen Lamps
Please Note: Continuous product improvement requires we reserve the right to change these specifications without notice.
© 2006 Welch Allyn MC3693 Rev B Printed in U.S.A.
4619 Jordan Road
Skaneateles Falls, NY 13153-0187
Phone: 315.685.4347
Fax: 315.685.2854
www.walamp.com
Welch Allyn—Your Source For
Precision Arc & Halogen Lamps
Please Note: Continuous product improvement requires we reserve the right to change these specifications without notice.
© 2006 Welch Allyn MC3693 Rev B Printed in U.S.A.
4619 Jordan Road
Skaneateles Falls, NY 13153-0187
Phone: 315.685.4347
Fax: 315.685.2854
www.walamp.com