FUNCTIONING OF EQUIPMENT
s i l i c o n controlled rectifier is fired will deter-
mine the output voltage amplitude. Conduction
Single phase, 115 volts, 60 cycles per second
o f the silicon-controlled rectifier applies dc
( c p s ) , is applied to the primary windings of
v o l t a g e to the power supply output terminals
f o r the remainder of that half cycle. The gate
t r a m f o r m e r T1. Transformer T3 controls the
current pulse will then be applied to the outer
v o l t a g e to the power transformer T2 primary
silicon-controlled rectifier w h e n positive volt-
w i n d i n g s . The power transformer T2 second-
age is applied to the anode.
ary voltage is applied to the silicon-controlled
rectifiers SCR1 and SCR2 anodes, and diodes
C R 4 and CR5. The auxiliary power trans-
T h e negative output terminal is connected
f o r m e r T1 secondary voltage is applied to
to the output sense terminal. The output volt-
d i o d e s CR2 and CR3. Through the full-wave
age is then applied to variable resistor R3 and
rectifying action of diodes CR2 and CR3 and
compared with the reference voltage. If a dif-
t h e clipping action of diode CR1, a 20-volt
f e r e n c e in the output and reference voltages
a m p l i t u d e square-wave reference voltage is
exists, the difference will be amplified by am-
f o m e d . Transistor Q4 provides regulation of
plifier transistor Q1. Transistor Q1 output will
the reference voltage. Zener diode CR6 clamps
turn transistor Q2 on. Resistor R5 and capaci-
t h e transistor Q4 base voltage. The reference
tor Cl comprise a stabilizing feedback circuit.
v o l t a g e is then applid to the pulse generator
Transistor Q2 then assumes a collector current
unijunction transistor Q3 base to develop a
such that the output voltage error is corrected.
g a t e current pulse as determined by the time
Choke Ll, resistor R16, and capacitor C5 form
constant of resistor R8 and phase-delay capaci-
t h e output voltage filtering network. Variable
tor C3. The gate current pulse is applied to fire
the silicon-controlled rectifier having a positive
v o l t a g e vernier resistor R2 adjust the power
voltage applid to the anode. The time that the
supply output level.