We found this circuit in a magazine 73 for radio amateurs from the 80's. The circuit makes use of an epochal component which is programmed according to the table beside the diagram.
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...