3V Lamp Brightness Controller circuit diagram

Posted on Feb 6, 2014

Here`s a circuit diagram for setting the brightness of the light bulb. You simply use the second battery to make the fruits of this circuit works. Example usage of this circuit is to adjust the brightness of images for close-up photo shoot with a digital camera. IC1 works to generate 150Hz square wave which having a variable duty-cycle. When poten

3V Lamp Brightness Controller circuit diagram
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siometer P1 is fully rotated towards D1, the output positive pulses appearing at pin 3 of IC1 are very narrow. Lamp LP1, driven by Q1, is off as the voltage across its leads is too low. When potensiometer P1 is rotated towards R2, the output pulses increase in width, reaching their maximum amplitude when the potentiometer is rotated fully clockwise. In this way the lamp reaches its full brightness. R2 limits the output voltage, measured across LP1 leads, to 1. 5V. Its actual value is dependent on the total current drawn by the bulb(s) and should be set at full load in order to obtain about 1. 5V across the bulb(s) leads when potensiometer P1 is rotated fully clockwise.

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