TM 5-3610-285-14
(2)
Circuit description. Actuating MAIN DRIVE switch (S5) applies an ac voltage to transformer T1. This
voltage is stepped down to 16 V ac and rectified to dc by circuit CR1. This rectified dc voltage is now filtered by
capacitors C1 and C3, and regulated to 12 V dc by voltage regulator U1. When dryer fan switch (S3) is actuated, the
regulated 12 V dc energizes relay K603, which energizes the recirculation pumps B2 and B3.
e.
Developer and fixer replenisher pump unit circuit.
(1)
Provides power to the developer and fixer replenisher pumps. The circuit is activated by placing REPL
PUMP switch to MANUAL, or by placing the switch to AUTO and activating detector switches in film detector crossover.
Developer and fixer replenisher pumps will deactivate after detector switch has deactivated, and the film has had
sufficient time to enter the processor.
(2)
Circuit description.
(a)
Circuit board 600. Actuating the MAIN DRIVE switch (S5) applies an ac voltage to transformer T1.
This is stepped down to 16 V ac and rectified to dc by CR1. This voltage is regulated to 12 V dc by voltage regulator U1
and then applied to the detector roller assembly (MS1 and MS2).
(b)
Circuit board 500. With film present, detector switches MS1 and MS2 actuate, thereby delivering
ground potential (low) to pin 3 of voltage inverter U1 on circuit board 500. Output at pin 4 of U1 goes high. A high at pin
5 of U8 on circuit board 500 satisfies the OR gate with a high at output on pin 4. Transistor Q4 (NPN Darlington) is
turned on. Collector of Q4 is low, thereby actuating relay K601. Normally closed contacts 1/9 of relay K601 are now
open, thereby deenergizing the safelight receptacle.
Transistor Q5 (PNP Darlington) is also on. Output goes low.
This low is sensed at wire 84 to solid-state relay U5. Actuating dryer fan switch (S3) energizes the solid state relay U5,
thereby energizing the replenisher pump B4 (REPL PUMP switch S1 in AUTO). When film clears the detector roller
assembly (MS1 and MS2), pin 3 of voltage inverter U1 on circuit board 500 goes high and pin 4 goes low. This transition
from high to low at pin 4 of U1 triggers timer U7A by way of capacitor C13. U7A pin 9 goes high for a preset period
determined by resistor R3. At the end of that period U7A pin 9 goes low. This high-to-low transition triggers timer U7B
pin 6 through C15. U7B pin 5 now goes high, actuating feed signal buzzer DS1 for approximately one second.
f.
Timer bell circuit. Is activated by the STANDBY RESET switch. The circuit senses when film has passed
through the detector switches and signals a bell after a predetermined time interval to indicate when more film may be
fed into processor.
g.
Gage Illumination Circuit. Provides indirect lighting for the gages and flowmeter, and is controlled by the DRIVE
METER switch and LAMPS switch.
h.
Water Control Circuit.
(1)
Consists of a series of temperature controlled solenoid valves to aid in maintaining proper operating
temperature of wash water and developer.
(2)
Circuit description.
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