This symmetrical four voltage source was found in a 1968 Motorola documentation. The circuit is of a type that was commonly used in that time amplifiers.
This control for 1200 W of power was found in the documentation of General Electric of 1966 has a...
I found this circuit in an old English magazine from 1979, but it can be easily assembled with...
This circuit imitates the singing of a bird intermittently with the intermittency determined by C1...