This circuit was found in a 1967 RCA documentation. The components are of the time. The circuit limits the current to 50 mA when the battery is fully charged.
This circuit was found in a 1980s documentation. The low voltage circuit uses a PUT. Transistors can...
This circuit was found in an old Electronic Design used to apply digital signals to an analog...
Very simple, this radio control circuit for short distances was found in an Electronic Design from...