This simple optical alarm circuit was found in the 1991 Electronics Experimenter Handbook. The circuit uses a lamp as the emitter but can use LEDs.
This circuit was found in old documentation. D1 can be a diac. | Clique na imagem para ampliar...
The circuit shown was found in a 1967 RCA manual. Modern equivalent components can be used. The...
This shield can be used both to interface microcontroller circuits or TTTL. The resistor in series...