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.
The circuit presented was found in a European publication of the 1980s. Used transistors are not...
The integrated circuit used in this project is not common today, but it can be implemented with more...
Suggested by an old American documentation the circuit below keeps a battery charged and at the...