Short pulse relay circuit diagram

This circuit can transmit the ringing tone of a phone in one room to another room through a voice control circuit. There is no electrical connection between the phones in the two rooms. That is, when the ringing signal is received by the microphone, it is amplified and outputted and then transmitted to another headset.

This circuit can also be used in other situations. For example, if you want to control other processes through a relay, you can connect a circuit shown by the dotted line in the figure to the collector of transistor T3.

Main technical data of the circuit: Working voltage: 6 (3.5~9) V Working current (at 6V): 130uA/480mA Input signal action voltage: 8mV Limit frequency (3dB): 11kHz