IC CD4060
This is a simple home telephone ringtone generator circuit which is built with applying only several electronic components / parts.
It generates simulated telephone ringtone and requires only DC supply with 4.5V DC to 12V DC voltage.
One may possibly use this circuit in ordinary intercom or phone-type intercom. The sound is pretty loud when this circuit is operated on +12V DC power supply. Even so, the volume of ring sound can be adjusted.
Circuit Ringtone Generator
Working with a built-in
oscillator-type piezobuzzer generates about 1kHz tone. In this particular circuit, the piezo-buzzer is turned ‘on’ and ‘off’ at 20 Hz for ring tone sound by transistor T3.
20Hz pulses are obtainable at the collector of
transistor T3 for 0.4-second duration. Just after a time interval of 0.4 second, 20Hz pulses become again obtainable for another 0.4-second duration. This is followed by two seconds of nosound interval. Thereafter the pulse pattern repeats by itself.