This amplifier for playback of recordings was found in a 1947 manual. It uses a push-pull output with a tube power supply.
This simple PWM circuit was found in the March 1991 issue of Radio Electronics magazine. The...
This circuit divides the grid 60 Hz frequency to obtain 20 Hz to drive mechanical watches used at...
Originally, this circuit is from an English magazine, but I found it in Argentina's Radio Chassis...