This simple power supply, which is equivalent to 2 AAA or AA batteries, was found in an Elektor from the 90's. The transformer has a 4.5 V secondary with a current of 50 mA or more.
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...