TM 11-5855-217-12
the fan will continue to operate until the search-
light components have cooled to below 125 F.
When the beam switch is placed in the SPREAD
BEAM position, the focus drive motor moves the
f. Igniter. When the power switch is at INFRA-
xenon lamp away from its focal point toward the
RED or VISIBLE, 3,000 volts is applied to the
igniter. The igniter steps up the voltage to a
defocused or spread beam. Stopping the focus
nominal 40 kilovolts and applies this voltage to
drive motor anytime before the maximum beam
the xenon lamp. After lamp ignition, the igniter
spread is achieved, produces a variable beam (B
remains inoperative until lamp ignition is again
required.
to achieve maximum beam spread produces a
g. Booster. When the power switch is at IN-
FRARED or VISIBLE, the booster applies 3,000
e. Heat Exchanger. An air-to-air heat exchanger
volta to the igniter and 120 volts to the capacitor
with a centrifugal fan provides cooling of the
bank in the control box. Also, the booster supplies
xenon lamp and IR filter assemblies. The fan op-
10 volts to the vehicle power source to insure igni-
erates when the power switch is at INFRARED
tion of the lamp. After lamp ignition, the booster
or VISIBLE. When the power switch is at OFF,
becomes inoperative.
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