Telephone ringer circuit

[Jeff Haas]

I was looking into a telephone ringer circuit and found the following post on another message board:

http://www.controlbooth.com/forums/sound-music-intercom/17026-building-my-own-live-doorbell-phone.html
(Scroll down to post #5.)

Unfortunately, the poster didn't supply his schematic or code, and hasn't been active on that board since July 2011.

But I noticed that it was by someone in New Zealand. Hmm, could it be a member here? I couldn't find anything in a search of the board.

 

[JimPerry]

http://www.circuitdb.com/circuits/id/105 is the schematic, by Bill Bowden - uses a 556 duaL timer MOSFET and output transformer - 30 years ago I used to work with Bill in Calafornia!

 

[hippy]

Unfortunately, the poster didn't supply his schematic or code

I would guess the circuit part used is just the IFR510 plust transformer and couple of caps, then just a question of driving the FET with a square wave.