August 2015
What’s the difference circuit-wise between a “dimmable” and a “non-dimmable” 110V home LED light bulb?
Please log in to post an answer.
The non-dimmable variety use a largish electrolytic capacitor in the power supply, to generate a DC voltage, and then the LEDs are driven with a constant current circuit. So because of the constant current, the LED output is unaffected by supply voltage, so the brightness won't change with voltage(or dimming). Dimmable leds only have a small film capacitor, and the control circuit sets the current according to the input voltage (so they pulsate at mains frequency) and when dimmed the light output is chopped up similar to an incandescent bulb. The above applies to screw in bulbs, larger LED supplies may still use electrolytic capacitors, but within these another circuit measures the incoming duty cycle and adjusts the LED current to match.
