This is a circuit for receiving signals from the previous transmitter. The circuit uses a common phototransistor. It was found in the August 1984 issue of Radio Electronics magazine.
This low-cost MW receiver is from the SGS linear integrated circuit manual. The coil wire can be...
Here is a high-quality intercom for demanding readers. The circuit is from a 1982 documentation. Of course,...
With this circuit, a relay can be activated from an alternating signal with frequency up to a few...