This simple LED torch is driven by a 2-transistor blocking oscillator which steps up the voltage from a 1.5V cell. It relies on the inherent current limiting of the 150µH choke to protect the white ...

LED drivers that receive their power from a single cell are receiving a great deal of attention. To generate the high voltage for illuminating a white LED from a low-voltage power supply basically ...

An LED's brightness is directly proportional to the current through it, which creates a challenge for low-voltage and battery-powered applications. But it's possible to increase an LED's brightness ...