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.
Found in old American documentation, this circuit is current as it uses the 555 to modulate an...
This audio amplifier uses 3 transistor in a traditional configuration named complementary output....
The UM3562 integrated circuit is a dedicated circuit found in many toys because it generates three types...