- on Home & Garden
- Published in issue 7/2005 on page 0
Two-Cell LED Torch
This design uses a classic two-transistor astable multivibrator configuration to drive the LEDs via a transformer from two standard 1.5 V alkaline batteries. The operating principle of the multivibrator has been well documented and with the components specified here it produces a square wave output with a frequency of around 800 Hz.