Halogen
Lamps
Halogen Lamps
Laser Light Measurement Systems
LCD / DLP TV Lamps
Document Actions
Cold Cathode Flourescent Lamps
Cold Cathode Fluorecent Lamps are lowpressure mercury vapor
lamps.These lamps use the 253.7 nm ultraviolet emission from mercury
vapor
excited by electrical discharge through the lamp to cause strong
fluorescence in phosphors on the wall of the lamp. The amount of
mercury used is very small (several milligrams), but is sufficient to
supply the necessary saturation vapor pressure in the tube.
The vapor pressure is very temperature sensitive, which causes
the lamp output to vary after the lamp is turned on from a cold start.
The
optimum operating temperature is approximately 40 degrees Celsius. The
initial output from the lamp at room temperature is only 70% of the
steady state valueat 40 degrees, and is only 25% when the lamp is
started at 0 degrees. Cold starts require additional voltage from the
power source to ensure reliable operation. The following graph shows
the depen- dence of the various lamp parameters on the ambient
temperature.
Our Cold Cathode lamps are offered in both visible and ultra
violet
versions.Ã This catalog lists several standard lamps however
custom lengths and colors can be ordered to fit your design
requirements.
The visible lamps are supplied with white output, which
provides a high
color temperature, cool white light. Typical applications include
backlighting for LCD screens, scanners or barcode readers, and special
purpose illumination.
The ultraviolet lamps are available with a peak wavelength of
either
254nm or 350nm. The 254nm lamps can be used for sterilization of water
and food containers, toxicology, and biochemical testing. The 350 nm
lamps can be used for inspection applications, fluorescent photography,
ultraviolet curing and more.
The inverters used to drive our Cold Cathode Fluorescent Lamps convert either 5 volts or 12 volts DC to a high voltage, high frequency (30 kilohertz) waveform that can cause the formation of the electrical discharge in the lamps. The current is limited by the value of the coupling capacitor in the inverter to provide the correct power level drive to the lamps. These inverters are very small and lightweight while improving the efficiency over driving the lamp at 50 or 60 Hz. The inverter produces adequate excess voltage to ensure startup of one or two lamps over the operating temperature range of 0 to 50 degrees Centigrade.
