Old alarm systems

[Whitcrane76]

Coworker took this out and decided I needed it. I couldn't say no. Now I am just wondering, is there any fun to be had with it?

[rdelius]

Battery charger/ power supply

[Babybearjs]

hook it up to your phone system and watch the needle dance!

[RB]

The brain is missing, and, as pointed out, ps and batt, and a relay?.
May be a fun arduino project???
Be sure and thank your co-

[Jim Stettler]

A lot of old alarm systems use a reversing relay to transmit alarm and troubles. They would go to a mod alarm board at the local police station.
The mod alarm is an analog meter, zeroed to the center of the scale. Mormal position sends the needle on green. On alarm the voltage reverses and goes to the red. Lack of voltage/broken wire will cause the meter to stay in the middle range which is black indicating trouble.
Jim