How to make a Fake Telephone Ring Generator
This is a telephone ringer signal generator. It is made of a Stepping motor & small transformer.
Now, we can make a telephone ring sound without incoming call.
You can find Stepping motor from junk photocopier or printer. Small transformer is 220V - 6V(3~9V) transformer.
A stepping motor is an alternating current generator.
And converted to high voltage through the transformer.
Ringer signal is about 85~130 VAC 20 Hz signal.