This circuit uses only transistors and was found in a 2003 documentation. Transistor 2N3055 must be mounted on a heat sink and the voltage is set to R10.
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...