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 traditional signal injector configuration was obtained in a 1977 amateur radio manual. The...
An integrated circuit 741 (operational amplifier is the basis of this voltage indicator, which can also...
This commercial 6-digit clock circuit was found in August 1976 Radio Electronics magazine. Note...