Any high-gain Darlington transistor can be used on this touch circuit. The load can be formed by LEDs and the power supply isolated from the power grid.
This TTL circuit was found in the December 1990 issue of Radio Electronics magazine. The circuit has...
Found in an Electronics World of 1968 this circuit can use any SCR and diodes depending on the...
Placed near a telegraphic transmitter (CW) and with a small antenna or pickup, it reproduces the...