Are LED light bulbs dimmable?

Question

Are LED light bulbs dimmable?

Answer 1

The intensity of light that an LED emits is proportional to the amount of current passing through it..

yup you're right... reduce the current passing through the LED and it will dim out...

cheap and best method.. use a variable resistance in the circuit..

Answer 2

Yes, but not in exactly the same way as an incandescent. An incandescent is continuously variable from off completely to full on. An LED has a threshold voltage, below which it will not light. So, from full on,. you can dim just like an incandescent until the voltage drops to the threshold and the LED lamp will suddenly go OFF even though the dimmer is not fully off. LED stand for light emitting diode. It takes aboutn0.5 volts to forward bias the diode so it starts condunction current and starts to glow. As the voltage is increased to 1.5 volts, the current increases which makes the LED brighter. The brightness is directly related to the current passing through the junction which is glowing. If the voltage gets too high, the junction melts and teh LED fails from overheating. It is NOT "cold" light as a lot of people claim, but it is really LOW LEVEL heat until it gets hot enough to melt and fail. Even then, it doies not get hot enough on the surface to burn you, unlike a standard incandescent bulb. LED's will last much longer than any other kind of light source and give off less heat overall.

Answer 3

Yes they are, Use an in-line variable resistor.