Relay Assembly Test Board and Components Assembly A1

TM 11-6760-238-34

board and components assembly A4, and relay

the four-input AND gate and lamp driver transistor Q1

assembly test board and components assembly Al are

circuitry is discussed.

(1) Mount position four-input AND gate

discussed in a stage-by-stage manner. Remaining

circuit. The mount position four-input AND gate circuit is

circuitry contained within the test set is not sufficiently

complex to warrant detailed theoretical discussion. The

comprised of diodes CR3 through CR12, lamp assembly

overall test set schematic diagram is figure* FO-5 and

A6, lamp driver transistor Q1, resistor R1 and part of

individual simplified schematic diagrams serve as aids to

lamp assembly A5 and control relay K1. When MASTER

support the following test. The overall test set wiring

switch S3 is operated to the CONTROL PANEL position,

diagram is figure* FO-7 sheets 1 and 2.

externally connected ACCS master control MOUNT

a. Relay Assembly Test Board and Components

switch is in the 900 position, +28 volts dc power is

Assembly A1 (fig* FO-2)

applied through terminal R, contacts of energized control

(1)

Relay assembly test board and

relay K1, resistor R1, and diode CR3 to the base of

components assembly Al consists of a lamp driver

transistor Q1. Application of this positive voltage places

transistor Q1, to six-deck rotary selector RELAY ASSY

driver transistor Q1 in a current conducting state thereby

switch S1, diodes CR1 through CR31, and resistors R1

lighting the 900 lamps A5DS3 and A5DS4. When the

and R2. This assembly, working in conjunction with

ACCS master control MOUNT switch is placed in the 300

indicator lamp assembly A2 and MASTER switch S3,

R position, a ground signal is applied through pin C of

processes + 28 volts dc primary power and ground

CONTROL PANEL connector J6 to 300 R lamp A6DS3

control signals to provide lamp indications dependent

and also through terminal C of assembly A4 to diode

upon operational status.

CR5. In this operational state, the 300 R lamp is lit and

(2) When a ground signal is not applied to

diode CR5 conduction applies an effective ground signal

to the junction of resistor R1 and diode CR3. This action

pin H of RELAY ASSY connector and/or the RELAY

ASSY switch S1 is not in position 2 (switch marking), +28

effectively reverse-biases transistor Q1 to cutoff, thereby

causing the 900 lamps DS3 and DS4 to go out.

volts dc power is applied through resistors R1 and R2 to

Application of 150 R, 300 L and 150 L ground signals

the base lead of transistor Q1 and also directly to the

cause the respective lamps to light and in each instance

emitter lead of the transistor.

In this operational

the 900 lamps go out. When MASTER switch S3 is set

condition transistor Q1 is held in a cutoff state and the D

to the LAMP TEST position, a lamp test ground is

lamp is unable to light When a ground signal is present

applied through diodes CR4 and CR9 through CR12 to

at pin H, transistor Q1 conducts and the D lamp lights

the 900 lamps DS3, DS4 and all lamps in assembly A6

Zener diode CR31 protects transistor Q1 from a current

thus causing the lamps to light.

overload and subsequent breakdown Whenever

(2) Control relays K1 and K2. Control relays

MASTER switch S3 is set to the LAMP TEST position,

K1 and K2 and associated diodes CR1 and CR2 process

lamp test 28 volts dc and lamp test ground are applied to

115-volt, 400 Hz, ac power and 28volt dc power to

the relay assembly test board and components

produce a + 28volt dc E V/H converter output signal,

assembly, A1 and the A, B, C and D lamps, A2DS1

115-volt, 400 Hz, ac power; and +28-volt dc ready

through A2DS4 light.

b. Control Panel Test Board and Components

indicate signal to the ACCS master control under test.

These relays are energized when MASTER switch S3 is

Assembly A4 (fig. 2-1) Control panel test board and

set to the LAMP TEST position.

components assembly A4 consists of one four-input

c. Shutter Assembly Test Board and Components

AND gate, one three-input AND gate, two lamp driver

Assembly A8 (fig* FO-3). Shutter assembly test board

transistors Q1 and Q2, two control relays K1 and K2,

and components assembly A8 primarily consists of a

diodes CR1 through CR22, and resistors R1 and R2.

power supply regulator circuit, two operational amplifiers

The two control relays govern application of 28 volts dc

and associated lamp drivers, two control relays, and two

and 115 volts, 400 Hz ac power to the ACCS master

lamp driver transistor stages. This assembly processes

control under test. The two lamp driver transistors Q1

+28-volt dc power, bridge assembly photo-transistor

and Q2 control operation of the 900 and AUTO indicate

signals and various other signals and control voltages to

mg lamps respectively. The diodes are used as steering

develop various dc voltages, output signals, and

devices to control indicating lamp operation or as relay

indicating lamp control signals.

protective devices. The assembly processes control

(1) Voltage regulator circuit. The voltage

panel mode ground, mount position ground, and various

regulator circuitry consists of transistor Q1, zener diodes

control voltages to provide lamp indications thus

CR1, CR2 and CR3, capacitors C1, C2 and resistors R1,

denoting operational status of the ACCS master control.

R2, and R3 Primary + 28 volts dc input power is applied

Since the four-input AND gate and three-in-put AND gate

through pin B of connector XA8 to the network consisting

and associated transistor circuits are similar, only

of resistor R1, capacitor C1 and zener.

2-2