Door bell to payphone ringer

Thread Starter

Joe LaFever

Joined May 12, 2017
I am not familiar with the Elcotel Series 5 payphone but in any case I suspect that the ringer transducer is just a piezo sounder.

If this is the case then I would use one of the common electronic ringer IC's such as the KA2411 or CS8205.

This page might give you some ideas

The incoming 90V ringing signal is simply reduced in amplitude by the series 1uF cap and 5k6 resistor before being rectified and filtered to provide a DC trigger signal to the IC. After that the IC takes care of driving the ringer transducer.

Good idea! Thank you. My only thought that if the doorbell is pressed briefly, how long of a ring will it be?