Commanders Control Unit and R/T Control Unit Functional Operations

TM 9-1240-369-34

(1) Commander's control unit. The commander's

required for operation of the laser system. Such drops in

voltage may occur in operation because of heavy

control unit consists of the following circuits or

transient loads. The battery power supply unit consists

assemblies logic circuit card, readout circuitry assembly

of a power control circuit, a low voltage transient control

and an electronic component assembly.

The

circuit, the battery, the battery charge sensing circuit, a

commander's control unit provides the display status for

battery charger circuit, and a battery charger malfunction

the operator.

(a) Logic circuit. The logic circuit card consist

circuit. The power control circuit receives the +24.0 v

prime power from the tank via relay K1. The battery

of the circuitry for the RANGE RETURN SELECTOR

consists of 24 cells which supply + 29.0 volts to the

switches, the MALF indicator and test (TSW) switch.

system. The battery is charged by the battery charger

Then one of the RANGE RETURN SELECTOR switches

circuit whenever vehicle power is applied to the system.

is activated, this generates the appropriate range select

The low voltage transient control circuit detects when the

signal.

For example.

if the RANGE RETURN

battery power supply unit should be switched in as the

SELECTOR 1 switch is activated, the first signal is

primary power source for the laser range finder. Vehicle

generated and sent to the select logic in the power

battery voltage below approximately + 22.0 V is

supply unit. The RANGE RETURN SELECTOR 1 switch

insufficient to bring the Q-switch in the transmitter

is illuminated indicating which switch was activated. The

component assembly to full speed. Therefore, the +

RANGE RETURN SELECTOR switches are momentary

24.0 V Q-switch line is connected through diodes in the

pushbutton type and each has lamp drivers with a

power supply control circuit to both the battery and the

latching circuit. The malfunction logic consists of hex

vehicle power line, so that the source with the higher

inverters which displays the appropriate malfunction

voltage always drives the Q-switch.

number (1, 2, 3 or 4) on the RANGE (METERS) indicator

The BAT LOW lamp on the front of the commander's

depending on what malfunction has occurred. The logic

control unit indicates (lights) when the battery voltage

circuit also contains the circuitry for the TSW switch

drops below approximately +24.0 V. Momentary high

which tests to see if the indicators on the front panel are

current loads, such as charging the PFN, can cause the

functioning properly (see table 2-1).

BAT LOW lamp to light. As soon as the battery voltage

(b) Readout circuit. The BCD ranges are

recovers to a voltage above approximately + 24.0 V.

applied to the readout circuit (Z1 thru Z8). Also, the

The BAT LOW lamp goes out. If the condition is allowed

range returns are applied to this circuit. The readout

to continue, it can reduce the battery life and negate the

circuit consists of the decoder/driver circuits and

emergency capability of the battery power supply unit.

numerical readouts. There is a decoder/driver circuit and

However, when operating at below 0F temperatures and

an numeric display for each readout on the RANGE

the BAT LOW lamp lights, it is permissible to range 10

(METERS) indicator and also for the RETURNS

times prior to recharging. The BAT LOW indication does

indicator.

There are tour indicators (units, tens,

not mean that the system will not function properly.

hundreds and thousands) for the RANGE (METERS)

However, it is recommended that the battery be charged

indicator and one indicator for the RETURNS indicator.

at the first opportune time. The MALF 1 indication shows

The numeric display has seven segments, each segment

that the battery charging circuit is not operating properly

consisting of several diodes. Each display is a red

or that the battery temperature has fallen below -25 F.

numeric display (0 thru 9). The decoder/driver circuit

provides the appropriate input code for the display

The battery charging circuit malfunction circuit Q3 and

desired.

The decoder/driver circuit contains seven

Q5 detects a malfunction either in the battery charging

drivers suitable for driving the readout. The drivers are

circuit or as a temperature indication and causes the

controlled by a BCD decoding network which receives

MALF lamp to light. The BAT DR lamp warns that the

and processes the range and return signals and displays

laser range finder battery power supply unit battery is

them on the indicators.

supplying the power to operate the system. Continued

use of the system with the BAT DR lamp lighted will

outputs from the commander's control unit are the

negate the emergency capability of the battery power

following signals: test, manual reset, manual reset select,

supply unit.

first, second. and last. The test and test signals set

logic circuits for the selected mode of operation. The

Unit Functional Operations. The commander's control

and R/T control units functional diagram is illustrated in

figure 1-4.

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