Figure 2-2. Bridge Assembly A10, schematic diagram.

TM 11-6760-238-34

zener diode CR6. Diode rectifiers CR4 and CR5 process

selected light sensitive transistor) diode CR8 is reverse-

ac voltage from transformer T1 through pins U and of

biased and ground is applied through resistors R12 and

connector XA8 to produce full wave pulsating negative

R14 to the base of driver transistor Q2 The action cuts

dc output voltage which is filtered and smooth, by the

off transistor current conduction, applies positive voltage

filter comprised of capacitors C3, C4, and resistor R4.

to the base of transistor Q3 thereby causing transistor

The filtered output voltage is regulated by zener diode

Q3 current conduction Transistor Q3 current conduction

CR6 to a - 6.2-volt dc output and then a piled to terminal

lights SENSOR CAL lamp DS2.

(4) DATA and ELECT FLASH lamp driver

4 of operational amplifiers A1 and A2.

(3) Operational amplifiers and associated

transistors Q4 and Q5 DATA and ELECT FLASH lamp

lamp drivers (The operational amplifiers Al and A2 and

driver transistor stages consist of driver transistors Q4

lamp driver transistors Q2 and Q3 and associated

and Q5 capacitors C5, C6 and associated diodes and

circuitry. When the externally connected SENSOR

resistors. Since both circuits are identical, only the

switch S9 is placed in its CALIBRATED position,

DATA lamp circuitry is discussed.

(a) When the shutter mechanism data request

phototransistor signal energy is coupled through pin of

connector XA8 to the non-inverting input terminal 2 of

switch is actuated, + 28-volt dc power is applied through

operation amplifier Al. In addition, phototransistor signal

pin E of SHUTTER MECHANISM connector J3, diode

energy is applied through pin K of connect XA8 to the

CR20 and resistor R17, charging capacitor C5, and

inverting input terminal 3 of operation amplifier A2.

continues through resistor R19 to the base of lamp driver

When SENSOR switch S9 is in the OPERATE position,

transistor Q4 This action places the transistor in a

ground is applied to input terminal 2 of operational

current conducting state thus flashing DATA lamp

amplifier A1. Operational amplifier A1 and A2 output

A9DS1. The shutter mechanism's DATA pulse however,

signals are applied through diodes CR7 and CR8 to load

is not of sufficient length for the DATA lamp to become

resistor R12 When the operational amplifier output signal

illuminated. After the data pulse is removed, current

is of positive polarity, this signal is applied through the

stored in capacitor C5 discharges through resistor R19

diodes and base load resistor R14 to the base of driver

and the base of transistor Q4 thus holding the DATA

transistor Q2 thus causing transistor conduction. With

Lamp on for a time interval longer than the duration of

Q2 conducting, an effective ground is applied through

the data pulse.

(b) When MASTER switch S3 is set to the LAMP

resist R16 to the base of driver transistor Q3 thus cutting

off the transistor thereby keeping SENSOR CAL lamp

TEST position, a lamp test ground signal is ap-

DS2 from lighting When operational amplifier A2 output

signal is of negative polarity (when light is impinged upon

2-4