(2) Module 2A1 uses three temperature
assembly 2A1A1, Power Monitor, is a dc amplifier used
control circuits and a fan for precise temperature control.
to amplify the detected pump power voltage to a level
Temperature controllers A2, A3 and A4 are identical to
sufficient to drive a 1-mil meter, PUMP meter 1M5. An
2A2A1 except for the setting of the control resistor R2
integrated circuit operational amplifier (U1) is used as the
active element. This operational amplifier is identical to
for V1, S2 and S4, have panel lamps, DS1 and DS2,
that used in 1A1, Temperature Monitor, dc amplifier
(para 2-15b). This operational amplifier requires +12 V
respectively, across their terminals.
mounted on Module 2A1 panel, light when the
on terminal 7 and -12 V on terminal 4, supplied through
thermostats are open thereby indicating malfunctions in
card (P1) terminals B and H, respectively. The input
the temperature control circuits. (Refer to para 2-11.)
signal from 2A1CR1 (0.2 to 4 V) is applied to U1 terminal
Capacitors to suppress transients are placed across the
2 via card terminal K. PUMP meter selection switch 1S3
terminals of all three thermostats (S2, S3, S4). Primary
is connected across card terminals D and A. When 1S3
power (120 12 V) to the heaters enters through J1
is set to KLYSTRON OUTPUT, PUMP meter 1M5 is
terminals A and B. This power comes from the output
connected across these terminals; when 1S3 is set to
sides of Unit 1 line filters 1 FL3 and 1 FL4 and is present
OFF the circuit is open.
A variable resistor
whenever MAIN POWER circuit breaker 1CB1 is set to
(potentiometer) mounted in Unit 1 (R7 PUMP POWER
METER ADJ) is connected across card terminals C, L
powerline, is mounted on the panel of Module 2A1.
and J. Terminal L is connected to the wiper arm of 1R7,
(3) Safety switch S1 is described in
which is adjusted (screwdriver adjustment) to center the
meter (1M5) deflection. Variable resistor R5 in the
the 120-V line behind fuse F1, the interlock relay (1K1)
feedback circuit permits adjustment of the gain of the dc
will not close when F1 is open as well as when S1 is
amplifier. Whenever the gain is changed the meter
open. This prevents the applicator of dc power to
deflection may require adjustment via 1R7. The required
Module 2A1 when all of the temperature control circuits
gain depends on the detected voltage from the particular
crystal detector (2A1CR1) with which it is used. The
(4) The dc amplifier, Power Monitor A1,
input RF power to the crystal detector depends on the
requires +12 V and -12 V for operation. These lines are
particular klystron oscillator (2A1V1) with which it is
protected by indicating fuses F2 and F3, respectively.
The fuses are mounted on the panel of Module 2A1.
b. Power Monitor 2A1A1 (fig. 2-14). Circuit card
Figure 2-14. Pump Source Power Monitor 2A1A1, Schematic Diagram.