Using an LDR as a sensor and an operational amplifier this circuit was found in the Encyclopedia of Electronic Circuits volume 5 from 1995. The circuit triggers an optodiac.
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...