This circuit was found in the May 1959 Radio Electronics magazine. Its purpose is to provide bias voltages for circuits under test. The circuit is isolated from the power grid.
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime...