Remote Ringer for Telephone

Am 25.01.2011 22:13, schrieb Jim Thompson:

You can hook up to 3 or more phones in parallel on the line. (so there´s enough power) Using the capacitor+ringer from an old phone would be enough. You have up to 60vpp on the line during ringing. Imporant is that you shouldn´t build a DC path in parallel. You can use (AC ring+capacitor in series) in parallel or capacitor + rectifier + DC ringer.

What's an old phone ?:-) I can't recall having one die... except for the wireless types.

Anywhere to just buy the ringer?

Though I guess just buy a cheap Chinese-made phone and gut it ?:-) ...Jim Thompson

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

All of these look roughly the same:

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---Joel

Buy an old desk telephone from your nearest Goodwill or other charity shop (they can use the money) and gut it?

Yeah - look around for an old Western Electric type that's actually operated by the ringing voltage. In fact, I've even seen prebuilt boxes with only a ringer in them.

Lessee what Friend Google has to say:

Or, how about one of those 5 or 10 buck extension phones?

Or do you specifically want to design something? You could capacitate the line, and on the other side of the cap, rectify the ringing voltage and just power any ol' beeper, or whatever circuit you want. Maybe a half-wave rectifier to each of two _different_ beepers, so it'd make two distinct tones.

Of course, isolate the box - nobody knows how it mucks up their stuff if you accidentally ground one of their lines.

Have Fun! Rich

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Searching for 'Telephone alerts', I found this..

Cheers

H.

Even better-

H.

Closer and closer! Thanks!

I'm aiming to build a ringer that skips the first ring... hint, hint ;-) ...Jim Thompson

Somewhere I have a pile out of old WE SC 1A2 type business phones. Maybe 100.

The easiest is to buy an external ringer:

Why don't you just get a corded phone? They're cheaper than the 'remote ringer' thingamabobs and have the added 'feature' you can answer the call.

I being slightly evasive :-) I need only the ringer, for devious purposes :-)

But your catch is certainly the cheapest. Thanks! ...Jim Thompson

Well, you're an engineer, aren't you? ;) Open it up and wire across the hook switch so it can't go off hook.

Or, if you don't like it looking like a phone, take the guts out and mount in your own box.

Nah, he's an analog savant.

Cheers! Rich

Solved. Bought 10 units (five phone locations, 2-lines) from Hong Kong at $5 each. Loud!

Next problem:

I need a circuit that closes a relay after X rings, X adjustable.

As before, line-powered preferred.

Helpful to the solution, I think, relay needs to close for no more than maybe one second ;-) ...Jim Thompson

Uh, presettable CMOS counter, and a battery for the relay?

By "line-powered," I presume you're talking about the telco's 48V? You can't draw very much power from that at all, or they'll start investigating for faults in their trunks. And, of course, they'll trace it to you. >:->

Good Luck! Rich

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Not line powered but has an appropriate opto circuit. I wouldn't expect the load to be phone line powered.

Modify the circuit to fire a retriggerable monostable. Couple this to a counter / relay driver.

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