This circuit provides 2.5 W of power with 6 V supply and 4-ohm speaker. We found it in the Radio Electronics magazine of April 1990.
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...