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 was found in an Elektor from the 90s. The integrated circuits are not very common...
Mouser Electronics is making available the Texas Instruments DRV401 Q1 integrated circuit, a...
This circuit was found in a Popular Electronics from the 90s. The circuit uses general purpose...