This sensitive circuit for triggering relays was found in an old English publication. It works with alternating signals applied to its input. Transistors are general purpose types.
This circuit for incandescent light bulbs was suggested by General Electric in a 1980s...
This emitter-coupled transistor LC oscillator circuit was found in the May 1970 issue of Radio...
This circuit was obtained in a publication in 1976, but it can still be assembled today with the...