Low level DC voltages from the LVPS in the power supply card A1A1 enter
the voltage interface assembly A2A2W1TB1 of the transceiver housing
assembly A2A2.
The +24 V FILTERED powers the EVENTS X 100 counter
A2A2W1M1, and the internal and the exhaust fans. The +15 V and -15 V
power the opamp circuits in the receiver card A2A4 and the energy control
card A2A1A6.
The +5 V power the TTL circuitry and heater HR1 of the
transmitter heat exchanger assembly A2A1A5.
The laser cavity is the high pressure area located within the
transmitter. It contains the flashlamp and the laser rod used to produce
the laser beam. The flashlamp contains a gas, which must be ionized to
allow the lamp to flash when triggered.
The TRIGGER VOLTAGE pulse,
amplified by pulse transformer A2A1T1, ionizes the gases in the
flashlamp. Once ionized, the SIMMER VOLTAGE current maintains the gases
in the ionized state. When the microprocessor generates the signal F/T
TRIG, the flashlamp discharge assembly A2A2A1 allows the 700-1000 VDC PFN
voltage to discharge through the flashlamp.
This flashing of the
flashlamp initiates the lasing action in the laser rod.
The microprocessor counts the number of times that the laser fires and
generates the EVENTS COUNT DRIVE signal. The EVENTS COUNT DRIVE signal
outputs after the first 50 laser firings, and again for every 100 firings
thereafter. The signal goes to the EVENTS X 100 counter A2A2W1M1. To
determine the approximate number of times the laser has been fired, you
multiply the number shown on the EVENTS X 100 counter by 100. The laser
fires once for rangefinding and repetitively for designating. The EVENTS
X 100 counter does not reset when you turn the power off. It displays
the total number of laser firings since installation.
The transmitter heat exchanger assembly A2A1A5 cools the laser cavity.
Internal fan B1 circulates high pressure nitrogen to cool the flashlamp
and laser rod. The nitrogen transfers the heat to the heat exchanger
assembly. Exhaust fan B1 of the blower assembly A2A3 blows air across
the heat exchanger cooling fins to cool the heat exchanger.
Two
thermistors, A2A1RT1 and A2A1RT2, monitor the temperatures of the cavity
and exhaust respectively.
The two thermistors provide signals that
supply the overtemp comparator located in the energy control card A2A1A6.
If the temperature in the laser cavity exceeds the temperature of the
exhaust by a preset level, the comparator detects an overtemperature
condition, and causes a visual alarm.
c. Energy Control Function (figure FO-20 of appendix B). The energy
control function monitors the laser output to provide feedback to adjust
the laser energy as necessary. The energy
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OD1721
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