Dc lamp dimmer

Posted on Nov 15, 2012

A low power, low cost dc lamp dimmer for a two-wire portable `flashlight` can be realized with little or no heatsinking. In addition, a single potentiometer, R3 adjusts lamp brightness. Battery power is stored in Cl for Ul, which is a free-running multivibrator whose frequency is determined by Rl, R2, R3, R4, and C2.

Click here to download the full size of the above Circuit.

Ul drives the gate of Ql, turning it and the lamp ON and OFF at a rate proportional to the multivibrator duty cycle.

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