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.
This circuit is from a 1978 publication. It can be assembled with BC548 transistors for NPN and...
Wired to the output of any amplifier this circuit makes an incandescent lamp flash according the...
Other operational amplifiers in the series, such as the MC34072, MC34074, MC35071, MC35072,...