atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems How many ringers?

I don't know. I have a Stromberg Carlson 501 in my house now. It's got an Elgin power supply where the ring generator ( like all 1A2 power supplies that I'm familiar with) is not fused. I've got 4 or 5 phones ringing on any particular line at any given time and have never had a problem in 30+ years.

I remember 584 panels on the job where each of the 13 lines typically rang on 4 or 5 lines and there were times when all of the lines were ringing simultaneously. We occasionally had to change out a power supply, but not often.

Sam

That's pretty much a clone of the ITT 501, no? The only difference between yours and mine is the power supply. This is rated at .05 amps which seems to be a common figure. I opened the power supply because a screw fell in while I was removing 30 years worth of hackery and returning the factory wiring to its factory configuration. Someone had removed a bunch of the internal wiring from the blocks and bunched it up to free up some spare rows on the blocks. Sigh. The point I was trying to make is the transformer for the ringing supply looks chunkier than the .05 amperes its rated for. It looked like something that could put out half an amp or better. I know looks don't mean a damn thing, but maybe they derated these things as a CYA kind of thing. Who knows?

Where's Ed? He's been kind of quiet lately.

Found this https://www.wedophones.com/Manuals/Itt/ITT%201A2%20601-501A-512A-584C.PDF


Boy, reading that brings back a lot of memories.

I had some bad dreams about Amps and butterfly tools back in the
80's.

If my math and resources are correct, a 1 REN phone would draw approximately .013 amps (90v/7000 ohms).

Sounds reasonable.

Since the 584C panel is the only device that we have discovered, so far, that has its generator supply input fused, and it's fused at 0.5 amp, then we can divide .5 by .013 and get the maximum number of ringers that will sound at once.

.5 / .013 = 38.46