TM 11-5820-765-34
ACTION:
Manually adjust dc voltage adjust R4.
Resistors
R4,
R8
change
setting.
Control circuitry in PC101(A1) senses change.
RESULTS:
Output voltage changes proportionally.
RESISTOR
FUNCTIONS:
R4 adjusts output voltage.
R8 adjusts voltage range.
1-12. CONTROL CIRCUITS
CIRCUIT
CARD
ASSEMBLY
PC101(A1):
Controls
power
supply
operation.
Senses voltage changes in ac input, dc output circuits.
Controls operation of voltage regulation, overvoltage circuits.
Derives power from two secondary windings on transformer T1.
V O L T A G E REGULATION CONTROL
PC101(A1) CONNECTS TO:
Silicon controlled rectifier SCR1(Q1).
Power supply's final dc output voltage.
NOTE
SCR1(Q1) regulates dc output voltage.
ACTION:
PC101 (A1) applies signal to SCR1 (Q1) gate.
SCR1(Q1) fires, conducts current after receiving signal.
Timing of control gate signal appears on gate.
TIMING:
Timing of control gate signal depends on value of output voltage fed to PC101(A1).
IF: Do output voltage increases
THEN: Time constants in PC101(A1) delay firing SCR1(Q1)
S O : SCR1(Q1) fires later in half-cycle
WHICH: Reduces output voltage
This restores output voltage to proper value.
IF: Do output voltage decreases
THEN: SCR1(Q1) fires early
WHICH: Raises voltage to proper value.
First Power Supply to PC101(A1)
POWER:
Plus and minus 20 volts.