Home Technology
LED Christmas Lights and How to Fix Them

David, a Make: reader, writes in:

Here’s a page describing how LED Christmas lights work. I found this site while searching for a way to repair a string of LED lights. This answered a lot of questions I had, like why the LED lights flicker, and why there is no obvious transformer or voltage converter in the string.They also have a page on incandescent Christmas lights and how to troubleshoot/repair them.

7 thoughts on “LED Christmas Lights and How to Fix Them

  1. I too have the exact same phillips LEDs. The blinking is enough to make me nauseous if it is the only source of light. There is however a solution! The Sylvania LED Micro-Style Lights (purchased from BJs) have some kind of phosphor like effect, when you pull the plug the glow slowly dies over the course of 20-30 seconds. As far as I can tell these lights have no discernible blinking effect.

  2. The reason that LED x-mas lights flicker is very easy, LEDs are a DC device, you can pass AC though them BUT will only light when the current is going the right direction and because AC is flowing backward half the time the current only goes forward half the time, BUT there is also the thing that in a normal AC power wave voltage is not high enough to light the led, SO the LED in these light is on only 1/3 of the time. So when you are looking at you LED x-mas light they strobe at 60 hertz. (by this is worse with blue or white because they use a voltage doubler to get them to trigger which can make the spike worse)
    Now one fix is to take and pass the AC though a rectifier and use capacitors to filter out the ripple (standard DC power supply) it is the reason why those sequencer lights look nice but the issue will be with the blue and white led lights because the voltage doubler converts the 120 to 220 so they can power them (white needs 3.5 to 4.5 to light up, red and green only need 1.5-2.5 volts)

    If the flicker bugs you you could put the lights behind something or put them in a flasher device. Other wise spend a few bucks more on the ones that use a power supply to run them (Strip type often due)

Comments are closed.

Tagged

current: @adafruit - previous: MAKE, popular science, hackaday, engadget, fallon, braincraft ... howtoons, 2600...

View more articles by Phillip Torrone