The circuit is from old documentation but can be implemented with any modern power MOSFET. The type of MOSFET depends only on the voltage and current of the controlled load.
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...