Audioguru again
- Joined Oct 21, 2019
- 6,673
A blue LED might measure a forward voltage of 2.82V when fed 200uA from my digital meter. But when connected directly to a 3.0V CR2032 battery it might draw 300uA and still produce plenty of light at night, especially if its lens focusses all its light into a narrow beam. Then the battery will last for days.
But most little LEDs are used at a current of 20mA which is 67 times higher and the little battery will die soon.
But most little LEDs are used at a current of 20mA which is 67 times higher and the little battery will die soon.