The selected circuit is from the Texas Instruments optoelectronics manual. With it you can receive optical signals in CW. Transistors support equivalents.
Found in a 1966 American publication, this circuit invert the phase of a low frequency signal. The...
This circuit provides two slightly different audio signal outputs from a monophonic audio signal, so...
This circuit, from a 2006 documentation, automatically controls the activation of a water pump, and...