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 small analog TV transmitter was found in an Electronics Now from the 90s. The range is around...
We found this circuit in the 1982 SGS Linear Integrated Circuits Manual. Diode D1 prevents the...
We found this oscillator in a documentation for radio amateurs from the 1970s. The circuit can use...