4-3. MODULE FUNCTIONAL DESCRIPTION
PRIME POWER APPLICATION Prime power is 115-volt line-to-neutral, 400 Hz, 3-phase. Power is applied to test set
through POWER IN J4 jack. Because test set does not use a neutral line, power within the test set Is 200-volts, measured
line-to-line. Circuit breaker 1CB1 supplies power to the test set and provides circuit protection. Filters FL1, FL2, and FL3
remove rf signals and electrical noise from power lines. When 1CB1 is set to ON, 200-volts line-to-line is applied through
filters to primary of 1T1 and to contacts of relay 1K1. Transformer 1T1 supplies three 3-phase outputs to power supply
regulator module 1A3: 2 6 Vac, 8.1 Vac, and 7.4 Vac.
POWER DISTRIBUTION With three secondary voltages from 1T1 applied to power supply regulator module 1A3, 1A3
generates four dc voltages: +28V, +20V, +5V, and -5V. If a short circuit occurs In any dc circuit, 1A3 turns off that dc
output. Relay 1K1, with +28Vdc from 1A3 applied to its coil, energizes and provides 200 Vac line-to-line to signal
processor through SIGNAL PROCESSOR POWER J1 If a signal processor is not connected to J1 jack, an interlock circuit
(INTLK1) on oscillator and switch module 1A2 de-energizes 1K1 to remove 200 Vac from J1.