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.
This circuit was found in the magazine of radio amateurs 73 in a 90's edition. The components are...
The circuit shown is suggested by National Semiconductor in its 1994 Linear Applications Handbook. We...
This circuit allows the "recovery" of weak signals recorded on tape that correspond to programs. The...