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 ...

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 ...

[michimartini] over on Hackaday.io loves playing with multivibrator circuits, and has come across a simple example of a ring oscillator. This is a discrete transistor RC-delay design utilizing five ...