(1) The LVPS provides a source of low level DC voltages to operate
the LD/R. The four DC voltage outputs from the LVPS are +24 V, +15 V, -
15 V, and +5 V. The +24 V provide power to the PFN, and the simmer power
supply in the power supply card. The +24 V also go to the transceiver
assembly A2 to power the EVENTS X 100 counter A2A2W1M1 and the events
counter drive circuitry in the control logic card. The +24 V drive the
cooling fans in the transmitter heat exchanger A2A1A5 and in the blower
assembly A2A3.
The +15 V and -15 V outputs supply the PFN, the simmer power supply, and
the 450 V power supply located on the energy control card A2A1A6. The +5
V output provides power to the transistor logic (TTL) circuitry
throughout the LD/R, and to the DISPLAY BRIGHT switch A1W2R2 to control
the display illumination circuitry.
(2) The simmer power supply provides a current to keep the
flashlamp of the optical bench assembly A2A1 ionized.
The flashlamp
gases must remain ionized to allow the PFN output to discharge through
the tube.
A -400 V pulse, TRIGGER VOLTAGE, supplies the pulse
transformer A2A1T1 to produce a 20 kV output that ionizes the gases in
the flashlamp. The SIMMER OUT signal of 90 mA goes to the PFN input of
the flashlamp to keep the gases ionized. If the simmer current drops
below the level required to maintain ionization, another TRIGGER VOLTAGE
pulse occurs to re-ionize the gases in the flashlamp.
(3) The PFN output also goes to the transmitter. The PFN VOLTAGE
signal ranges from 700 to 1000 VDC, and discharges through the flashlamp
via the flashlamp discharge assembly A2A2A1 of the transceiver housing
assembly A2A2.
With the POWER switch held to the AZ ADJ position, the ON/AZ ADJ signal
goes to the power supply card and to the logic control card to operate
the LD/R in the AZ ADJ mode.
The switch spring returns to the OFF
position from the AZ ADJ position.
The FIST controls, when used, take over control of the G/VLLD set. The
signal FIRE REMOTE-FIST enters the LD/R via connector pin 1J7.
It
supplies +24 V to the LVPS to turn on the system. The POWER switch on
the LD/R must be in the ON position during FIST operations.
b. Transmitter Function (figure FO-19 of appendix B).
The
transmitter function consists primarily of the flashlamp and the laser
rod located in the laser cavity. When triggered by the microprocessor U9
of the control logic card A1A2, the flashlamp flashes to initiate lasing
action in the laser rod.
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OD1721
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