LED Light in Ceiling Fan only works with a non-LED next to it

Question

I have a Harbor Breeze ceiling fan with two light ports and a remote control. The lights are e12 (candelabra) base, but I need some brightness. I just bought some 12W LED bulbs (100w equivalent) and discovered something weird that I can work with, but I would like to know why it's happening. If I only have 1 bulb in, or if I have 2 LED, they don't work....but if I have 1 LED and one incandescent one, the LED works. I noticed that with just 1 LED, it seems to dimly pulse about every 2 seconds, but never comes on. I specifically bought dimmable bulbs....I'm curious why it works with an incandescent in there, but not otherwise

Answer 1

LED bulbs work by using a power supply board (called a "driver) that converts your AC line to low voltage DC. The driver board takes very little power at first, then it excites the LED to make it glow and pulls a little more current. If your fixture uses solid state relays (SSRs) as the dimmer inside, those often require a minimum amount of current flow in order to function. If the LED driver current consumption is at or below that threshold, the SSR dimmer in the fixture fires, but will not stay on because there is not enough current flowing so it turns off again. When you add an incandescent bulb, you add enough current so that the SSR functions. This is what JPhi1618 meant when saying that the dimmer in the fan may not be compatible.