This circuit was obtained from a 1967 General Electric manual. The circuit makes use of absolutely current components. Similar versions from other sources can be found in this section.
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...