Competition (#3) entry: solar powered night led’s 2010-08-07

This project uses a lead-acid battery to power some strings of LED’s at night for illumination of my patio. The battery is recharged with a solar panel. The panel is monitored and is used like a photocell to turn on the lights at night and off at dawn. The LED’s energized with a PWM voltage to conserve power.

Theory of Operation

U1 is a three terminal 12V lead-acid charger that requires no external parts for charging the 12V battery. When the power switch S1...

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