We found this circuit in Ferranti's 1974 transistor manual. The components are from the period. Note the relay type used.
This circuit was found in an Electronic Experimenter Handbook from the 90's. The coil can be...
This touch switch uses components that have easy-to-obtain current equivalents. The power supply...
This circuit is an excellent shield for microcontrollers and was found in the October 1987 Radio...