DETAILED CIRCUIT DISCUSSION - TM-11-5805-688-14-10274

T.O. 31W2-2GSC24-2

TM 11-5805-688-14-1

NAVELEX 0967-LP-545-3010

is also applied to the +5-volt regulator circuit on +5-volt

Each switch, in turn, generates equal amounts of energy

regulator card A2.

that is coupled to its associated rectifier circuit. The four

dc outputs from the rectifier circuits are connected in

5-633.The +5-volt power supply consists of amplifier

parallel and applied to the one +5-volt filter circuit. The

AR2-10, switch Q7, breakdown diode VR8, and amplifier

output from the filter circuit is the +5V Reg output that is

Q5, Q6. Amplifier AR2-10 and switch Q7 form a low

applied to power the logic cir- cuits in the multiplexer set.

input voltage protection circuit for the overall power

supply. When the incoming 115 vac decreases to 95 vac

5-630. DETAILED CIRCUIT DISCUSSION.

or less, the inverting input to AR2-7 decreases and the

output from AR2-10 to Q7 goes more positive. Switch

5-631.The incoming 115-volt ac source power is applied

Q7 is driven into conduction and effectively shorts out the

to the +150-volt power supply and to stepdown

voltage across breakdown diode VR8. This condition

transformer T6 as shown on the overall power supply

biases Q5 and Q6 into cutoff. When Q5 and Q6 are

schematic. The +150-volt power supply consists of full-

cutoff, the absence of the +5V (c) output shuts down the

wave rectifier CR1 through CR4, filters L4 and L5, and

overall power supply. When the incoming ac voltage

capacitors C18 and C19. The unregulated +150-volt

increases to 100 vac, the output voltage level from AR2-

output from the power supply is applied to one side of

10 decreases, switch Q7 is biased off, and Q5, Q6 again

transformers T1 through T5 to provide the driving power

conduct to produce the +5V (c) output. When the +5V

for switches Q1 through Q10. In turn, the +150-volt

common (return) from the opposite end of T1 through T5

are energized and return to normal operation.

is applied to the switch circuits through +12-volt driver

card A3 and +5-volt driver card A4.

Stepdown

5-634.The -12-volt over/under voltage detector circuit

transformer T6 produces a 18.5 vac input to full-wave

consists of comparator AR3-10, CR4, and CR3. The

rectifier circuits CR1 through CR4 on mother board A1.

+12-volt over/under voltage detector circuit consists of

Diodes CR2 and CR4 and capacitor C2 produce the

comparator AR3-12, CR5, and CR6. Comparator ARl-12,

+12V (c) output and diodes CR1 and CR3, together with

CR1, and CR2 make up the +5-volt over/under voltage

capacitor C1 produce the -12V (c) output. These two dc

detector circuit. The outputs of the three comparators

voltages provide power to the clock generator and the

are connected through CR2, CR4,

and CR6 to

control circuits.

breakdown diode VR1 in the inverting input of

comparator AR1-10. When the -12V Reg output

5-632.As shown on the +12-volt regulator card

increases to -14.4 volts, the output of AR3-10 increases

schematic, the constant current generator circuit consists

to cause current to flow through VR1. This condition

of current amplifier Q3 and breakdown diodes VR5 and

places a high in- put to AR1-7 to produce a low output at

VR6. Potentiometer R18 is factory set to provide a fixed

AR1-10. The low output from ARl-10 shuts off switch

bias voltage to amplifier AR5-12. Amplifier AR5-12, in

Q4. This inhibits the generation of the A clock and B

turn, produces the constant +4.77V Ref output that is

clock signals to disable the overall power supply

applied to AR2-10 in the +5-volt power supply and to

regulated outputs.

AR6-10 in the +12-volt regulator circuit. The +4.77V Ref

Change 2 5-173