This circuit is from a 1964 Electronic Design. The sensor is an LDR and the transistors are general-purpose types. The circuit triggers when the light that falls on the sensor is cut off.
This circuit is from the 1993 Motorola Linear Interface Circuits. The source does not have to be...
This range is normally used in marine communications as indicated in the 1989 documentation. The...
This shield circuit is from a 1968s Motorola documentation. The relay is according to the supply...