The Siren Board

Can it handle more than one, or does a city with multiple sirens have a different control for each one? Can a non-Federal siren, like an Allertor, be controlled by an AR timer?

I am not exactly sure but I think that multiple sirens can be controlled from one AR timer.

Yes it can control several sirens at once. That's how the old bell system of leased lines worked. One AR timer could run an entire city full of sirens.

That is what I thought.

Can a non-Federal siren, like an Allertor, be controlled by an AR timer?

An AR timer can control any mechanical siren with a motor starter, and any small 5 amp and under siren like a model A or D

holler wrote:Yes it can control several sirens at once. That's how the old bell system of leased lines worked. One AR timer could run an entire city full of sirens.

That is how Sheboygan activates our sirens.

All you need is a dry, unconditioned pair, a -48V DC power supply, and 'telephone' relays... To simply close the control circuit at each location.

The AR timer, when placed across a master relay, at the control location would be used to tell the rest of the relays what to do... The additional relay, though not needed, provides an extra level of isolation for equipment. At the control and at each site is (extremely important!) a standard Seicor, Siemon, WE, or other "telco" type demarc box, for lightning protection.

You could use any voltage between 12 and 120 volts DC at a few mA to control the relays, since telco pairs are typically operated to 120 volts @20Hz when the phone rings...

I use a similar setup to control my 2T. The AR timer switches power on and off to a doorbell transformer, which activates a relay at the siren which controls the motor starter. I wanted a low voltage control setup that was "dead" until the siren was activated, so if the wires got shorted together somehow the siren wouldn't go off by itself.

Hmm, Jeb that's interesting! Thanks to most of you for solving the questions about how my SD-10's worked, since all of them having Bell Systems telephone relays to close the circuit of the motor starter.