This simple charger was found in a 1980s documentation. The transistor may be the TIP42 with a heat sink. R1 adjusts the load current. The transformer has 1 A of secondary current.
Found in a 1980s documentation, this circuit detects when the voltage drops below 11 V. Other...
This is a commercial circuit from a Japanese publication from 1972. The circuit uses a FET that...
In this circuit we show how to modulate the pulses produced by a 555 in frequency. The circuit can be...