Emergency Power Supply

TM 5-6350-262-14/5

NAVELEX 0967-466-9053

TO 31S9-4-38-1 Chg 3

6-3. Emergency Power Supply

6-4. Duress Alarm Circuit

a. Battery. A 24-volt 20-ampere hour battery automatically

a. Input. Duress signals from Alarm Latching Switch SA-

supplies the control unit with operating power in the event of a

1954( )/FSS-9(V) are applied to the control unit between

failure in the external ac power supply. The battery is capable

terminals 1 and 2 of terminal board F. An impedance

of sustaining control unit operation for a minimum of 24 hours

between these two terminals of 0 to 20,000 ohms is

without requiring charging. The battery can be discharged

processed by the control unit as a no-alarm signal input. An

and recharged 200 to 500 cycles. If the battery is not

impedance greater than 100,000 ohms is processed as a

completely discharged each cycle, 1000 or more

duress alarm signal input. Duress alarm signals are fed to

charge/discharge cycles of operation are possible.

connector pins J1-4 and -1 of alarm/tamper module Al. A no-

alarm input will result in approximately 0 volts dc output at

b. Battery Charger. The control unit power power supply

connector pins J1-6 and -8 (measured between test point

contains a duel charging circuit to maintain the battery in a

AITPI and ground). An alarm input signal will result in

full-charge condition. A fast charge circuit automatically

approximately 20 volts dc output at connector pins J1-6 and -

supplies the battery with a heavy charge charge current after

8. An alarm signal must last at least 100 milliseconds to be

an extended ac power outage. As soon as the battery is

processed by alarm/tamper module Al as a duress alarm.

charged to the proper level, the fast charge is automatically

Duress output signals (0 to 20 volts dc) from alarm/tamper

removed and the battery is floated on a trickle charge.

module Al are applied to connector pins J11-16 of alarm

identification module A 11, J9-8 of instantaneous alarm

NOTE

module A9, and J10-6 of latched alarm module A10. (Refer

to paragraph 6-6 for a description of the duress alarm signal

If for any reason the Control Unit and

identification and display circuit.) Instantaneous and latched

attached sensors are deactivated, steps

alarm output signals are discussed in paragraphs b and c

shall be taken to prevent the battery from

respectively.

exceeding a 6-month storage period

without recharging. This may be done in

b. Instantaneous Alarm Output. When a duress alarm signal

one of the three following ways:

is received, instantaneous alarm module A9 immediately

provides an alarm signal to control unit output terminal board

(1) For a Control Unit left in place and

S; and, in the test/reset operating mode an internal buzzer is

still connected to AC power, pull DC fuse

sounded to alert using personnel of receipt of an alarm. Each

F2: at the bottom of the power supply,

of these functions are discussed in the following paragraphs.

throw the power switch to ON and leave

ON. This will maintain a trickle charge

(1) Instantaneous alarm. From connector pin Jl-8

on the battery, thus preventing the

duress signals are applied to a 10-second timer via

battery from deteriorating.

instantaneous alarm module A9 connector pin J9-8. Relay

A9K1 contacts are in the position shown in figure 6-1 for a no-

(2) For the same Control Unit conditions

alarm (0 volts) input. In this condition a low impedance of 0

as 1 above AC power may be shut off,

to 2000 ohms exists between output connector pins J9-14 and

but a schedule of turning the AC power

-U. This no-alarm signal is routed from J9-14 to J 10-14,

ON for 72 consecutive hours.

through the normally closed contacts of relay A10K4, and out

J10-12. A duress alarm signal (20 volts dc) input activates

the 10-second instantaneous alarm circuit. When activated

(3) If the Control Unit is completely

the one-shot timing circuit provides a return path to the

disconnected, remove the batteries, and

ground buss for the 20 volts dc applied to the coil of relay

store.

Recharge batteries every 6

A9K1 and causes it to operate for 10 + 2 seconds. When

months. Charging supply shall be a

relay A9KI is operated, a high impedance alarm signal of

constant voltage source set between 30-

greater than 100,000 ohms is present between

31 volts, with a charging current not to

exceed 3 amperes per 20 AMPHR battery

for a 24-hour recharging rate.

6-2

Change 3