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Circuits designed by David Johnson, P.E.
Last Updated on:
Monday, December 25, 2017 02:05 PM
Master Category List - Dave's Circuits
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White LED Circuits
LED Circuits
Driver Circuits |
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3V BATTERY
POWERED WHITE LED DRIVER - 12/06/2010 |
The
circuit below will drive any LED color, including white LEDs, using a DC power
supply ranging from 2v to 3.3v. White and blue LEDs normally require over 3v,
so the circuit below uses a charge pump scheme to deliver a constant LED light
intensity from a voltage less than 3v. The LED is rapidly pulsed with 3ma peak
current, which remains fairly constant, even as the battery voltage changes.
The circuit is designed only for low LED current applications. A common CR2032
lithium coin battery should run the light for two days. A pair of 2.5 Amp-hour
AA NiMH
cells should operate the circuit for nearly a month. |
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Click on Drawing Below to view PDF version of Schematic |
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