Welch Allyn Solarc Light User Manual

TECHNICAL OPERATION GUIDE

TECHNICAL OPERATION GUIDE

Focused Innovation.

Focused Innovation.

TABLE OF CONTENTS

Introduction ............................................................................................................................3

S¯olarc Lamp Overview .........................................................................................................4

S¯olarc Lamp Advantages.....................................................................................................4

S¯olarc Lamp Operating Characteristics............................................................................5

S¯olarc Lamp Safety, Handling and Disposal ....................................................................5

Lamp Life & Maintenance ...................................................................................................6

Designing S¯olarc 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 S¯olarc lamps, that’s precisely
what they get. S¯olarc 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 S¯olarc 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 S¯olarc
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
S¯olarc 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 S¯olarc
products. Please read these instructions thoroughly
before use.

S¯olarc®—The brilliant component

for successful products.

3

S¯olarc LAMP OVERVIEW

Each S¯olarc 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

ight emitting diode (LED) illumination sources. Light is

l
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.

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.

S¯olarc lamps have unique operating and handling
characteristics that should be understood to achieve
successful and reliable operation:

•S¯olarc’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

• S¯o larc is a direct current (DC) lamp, and proper electrical wiring
polarity must be observed to prevent damage to the lamp

Precision Focus

S¯olarc 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

ery small areas, such as projection display panels or

v
fiber optic cables.

Portability

Because they offer low-power arc lamp operation, S¯olarc
lamps allow you to design smaller, lightweight and portable
products. For example, a 21 W S¯olarc 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, S¯olarc’s low power draw (10, 18,
21, 24 or 50 W) makes battery operation possible, thus
enhancing your product’s value to your customers.

Shock Resistance

S¯olarc’s arc lamp generates its brilliant illumination with
precisely aligned electrodes in place of a tungsten filament.
This design enhances S¯olarc’s durability against shock
or vibration, making it an ideal lamp for products that
demand superior illumination in rugged operating
environments.

Consistent Light Output

S¯olarc’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.

S¯olarc LAMP ADVANTAGES

Brilliant Illumination

Thanks to Welch Allyn’s patented design, the S¯olarc

c lamp pr

miniatur
with a high color temperatur
solar-quality brightness, true color rendition and true color
balance, ensuring unparalleled r
lighting pr

e ar

oduct application.

ovides pur

Low Power Draw

S¯olarc 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,
S¯olarc allows you to design products that are more
compact, flexible, r

4

eliable and ef

e, white illumination

inherently provides

olarc

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esults for vir

ficient.

tually any

Easier to Use

High-efficiency operation—combined with its lower gas
volume and miniature size—mean that S¯olarc lamps
provide solar-quality light output, yet require 1/3 less
power than halogen lamps. Additionally, S ¯olarc lamps’
low wattage generates less heat that halogen lamps. This
feature allows you to design products requiring less
complex ther
of these features is that you can design products that
deliver optimum performance and safety at a lower
manufacturing cost.

mal management systems. The net r

esult

Welch Allyn Quality

Every Welch Allyn S¯olarc lamp is designed and
manufactur
and tight tolerances to ensur
exact specifications. By demanding pr

om our lamps and our manufacturing pr

fr
will ensur

ed within our strict production standards

e that each operates to its

ecise performance

ocesses, we

e the value of your pr

oducts.

S¯olarc LAMP OPERATING CHARACTERISTICS

Appearance

S¯olarc lamps contain small amounts of metals. These metals

re in both liquid and solid forms when the lamp is cold.

a
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

S¯olarc 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

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.)

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. S ¯olarc lamps are generally

esigned, built, and characterized using the lumen as the

d
measure of output and using maintained lumens as the
measure of output over time. Because S ¯olarc 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. S¯olarc
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.

LAMP SAFETY, HANDLING & DISPOSAL

Ballast Compatibility

A ballast is the electronic control circuit required to operate
a discharge lamp. S¯olarc 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 ar
the electr
very high voltage (~10 kV) and very short (<1 microsecond)
pulses to star
sound like a series of clicks. Again,
operated and there is a distinct polarity associated with
proper electrical connection. Improper wiring can cause
either lamp or ballast failur

c must be struck across the gap formed by

odes. T

o do this, the ballast generates a series of

t the lamp. They can often be heard and

olarc lamps are DC

¯

S

e.

Operating Orientation

S¯olarc’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. S¯olarc 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.

Safety

As with any high-power lighting system, it’s important to
remember specific safety issues. The S¯olarc 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 or
internal failures.

Always allow lamp to cool before replacing. Do not

emove the lamp fr

r
completely. For optimum performance, avoid handling the
bulb or the reflector. Fingerprints or other contaminants
on the glass may r

der to pr

otect the pr

om equipment until it has cooled

esult in per

oduct against any

mance degradation.

for

5

LAMP SAFETY, HANDLING & DISPOSAL

c

ont’d

LAMP LIFE & MAINTENANCE

Photobiological Safety Compliance Standard RP-27.3

s with any S ¯olarc product, UV precautions must be

A
taken when directly handling the lamp. Ultraviolet, visible
and infrared radiation are emitted from metal halide lamps.

ossible skin or eye irritation can result from exposure to

P
the output of a 21 W S¯olarc 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

S¯olarc 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 industry standard for reporting lamp life is median

ours—the point at which 50% of the lamps have stopped

h
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.

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. S ¯olarc 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. S¯olarc lamps will maintain a high level
of both chromaticity and light intensity throughout
their lives.

6