This circuit was obtained in an old Elektor and can be adapted to use white power LEDs. The transistor must be equipped with a heat sink. The circuit has a battery charger.
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...
This tunnel diode circuit was found in American documentation from 1966. The tunnel diode is the...
This circuit provides two slightly different audio signal outputs from a monophonic audio signal, so...