We found these circuits in a Popular Electronics from the 90s. The circuit has a simple low power version and a higher power version with MOSFET (VMOS) of the time.
This circuit was found in a 1963 publication. Its purpose is to convert sinusoidal signals from...
This simple circuit of low power with an LM386 includes the highly sensitive audio preamplifier...
Another alternate action switch that uses a NAND Schmitt Gate [4093 IC] is shown here. The...