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.
We found this circuit for receiving shortwave on a mediumwave radio in a 1986 Hobbyst Electronics PE. The...
With the light falling on the LDR, the relay closes its contacts by activating a warning system. The...
This circuit comes from a Gernsback Publications of the 90s. The circuit uses a general-purpose transistor as...