The reference voltage for this circuit can be selected digitally. The circuit is from Radio Electronics dated February 1981. The 741 must be powered by a symmetrical source.
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...