This battery circuit provides a charging current of 500 mA depending on the solar panel. The switching circuit is from a National Semiconductor documentation from the 90s.
Found in a 90s Radio Electronics, this circuit is intended to drive a neon lamp from a 9 V source....
This simple tester was found in a Popular Electronics from the 90s. The circuit is powered by two...
Electronics Now from the 90's suggests this pulse conditioner circuit for use in tachometers. The...