Dimming non-dimmable LEDs

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Dimming non-dimmable LEDs

Postby Commodore White » Tue Jan 14, 2014 10:53 pm

Please forgive the ramblings of a newbie.. but

As far as I know LED lights are diodes and only function when current passes in one direction. Since the mains supply is alternating current, a diode will only illuminate on the positive or negative excursion. I assume one of two possibilities exist. LED lamps consists of a bridge rectifier so they can exploit both +ve and -ve voltage swings OR LEDs are wired back to back.

Either way, could I not reduce the brightness of LED lights by simply wiring a diode in series with it.

It works with incandescent lights - why not LEDs ones?

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Re: Dimming non-dimmable LEDs

Postby qbic2005 » Wed Aug 27, 2014 3:04 pm

While it might actually work, this might not be a very good idea.
Most people will see the 25Hz frequency, I had a cheap led bulb that had diode inside instead of a bridge rectifier. It was annoying as hell.

Best method I found so far is to use a led spot on 12v that allow for pwm (pulse width modulation) dimming. you might not find them in your local home depo, but there are quite some good ones around. And it might be more difficult to find an adequate controller.
The advantage is that you will keep the correct light color and the maintain the live expectancy.
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Re: Dimming non-dimmable LEDs

Postby raymonvdm » Thu Aug 28, 2014 8:15 pm

NON dimmable leds are only non dimmable if they are 230Volt light bulbs and this is due to the power supply used to get from 230 volts to 12/24 volts

I just recently bought a Fibaro RGBW node, which has the ability to dim using PWM and i use this for my IKEA leds strips i have i some rooms. It has four channels (RGBW) but i use it for four different white led strips as long as you don`t use more than 6A on a single channel

http://www.fibaro.com/manuals/en/FGRGBW ... .1-2.3.pdf

Note: U need some sort of z-wave controller to control this device (Aeon Labs Z-Stick and pc for example)
Running HS3PRO on PC with Z-Wave / OpenTherm / Plugwise / RFXcom / MQTT / XAP400 / Logitech Media Server and Squeezelite on PI`s
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