This is the receiver for the previous circuit we found in the December 1992 Radio Electronics magazine. The sensor is a photodiode that must have optical features such as lenses.
This general-purpose two-transistor circuit was found in the November 1993 issue of Electronics Now. The...
This circuit with integrated TTL 7400 has a good teaching purpose, drawing one of two LEDs. The...
This circuit is from 2002 documentation, requiring a symmetrical source of 6 to 12 V. The signal...