RECEIVER-TRANSMlTTER INTRAUNIT CIRCUIT FUNCTIONING.

TM 11-5820-670-30

1-57. POWER SUPPLY ASSEMBLY A9500. (CONT)

REGULATOR OPERATION

The series regulators, connected in parallel, increase the current capabilities of the power supply and

maintain +24 vdc at a constant level.

If the required 24 vdc level increases above 24 volts, conduction of the voltage sensors decreases,

causing conduction of the regulator driver to decrease. Decreased conduction of Q9507 causes

decreased conduction of the series regulators, which then decreases the required voltage level to 24

volts.

If the required 24 vdc level decreases below 24 volts, conduction of the voltage sensors and regulator

driver increases. This action causes conduction of the series regulators to increase, thereby

increasing the required voltage to 24 vdc. Potentiometer R9511 controls the output voltage level.

1-58. RECEIVER-TRANSMlTTER INTRAUNIT CIRCUIT FUNCTIONING.

This paragraph will explain distribution of primary power, dc operating power, and the metering

circuit. All are contained in the receiver-transmitter and are explained here to clarify intercircuit

relationships that were not evident in the module signal flow analysis. See FO-11 while reading this

paragraph.

DISTRIBUTION OF PRIMARY POWER

Unregulated +27.5 vdc primary power is supplied to the receiver-transmitter at pins 18,34, and 36 of

main power connector P9601. Pin 16 of P9601 does not receive + 27.5 vdc until the radio set is

switched to homing operation.

Primary power is connected through pins 1,2, and 9 of connector P9501 to activate the receiver-

transmitter power supply. The power supply couples unregulated +27.5 vdc through P9501, pin 13 to

the control coils of relays K9601, K9602, K9603, K9604, and K9606. Unregulated + 27.5 vdc is also

fed to the receiver-audio amplifier through pin 9 of connector P5501, rf control module through

P4501, pin 2, and to the gearbox assembly through pin 25 of connector P9701.

Regulated +24 vdc is coupled through P9501, pin 8 and P5501, pin 29 to receiver audio amplifier. It is

also applied to vhf tuner A1000, test switch S9601, P2101 pin 4 of voltage regulator A2100, and P9701

pin 23 of gearbox assembly A9700.

Regulated +24 vdc is also applied through pin 7 of connector P9501 to the control coil of relay K9605

and to contacts 2 and 6 of relay K9601.

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