This circuit provides a signal when dialing occurs. The circuit is powered by the telephone line voltage itself. We found it in an old documentation.
This 80's circuit makes use of a photomultiplier valve. The circuit also requires a scintillation...
This circuit uses only two general purpose transistors and can be powered by the circuit under...
This signal follower is from a 1970's documentation. So it uses the traditional configuration at the time...