This battery charger circuit was found in the August 1970 issue of Radio Electronics magazine. The circuit uses 4 transistors. Q1 must be provided with a good heat sink.
This small circuit for the medium or short-wave range, depending on the coil, was found in a...
This circuit from a 90s Electronics Now, uses a 4010 gate as a signal amplifier. The circuit...
Found in 1980s documentation, this circuit produces 1 Hz flashes. The op amp supports equivalent. R5...