Fix Flickering LED Christmas lights! (rectifying LED lights)

Often times when you find LED Christmas lights for sale, you might notice that they seem to flicker, especially if they move around. This is because they are not rectified, and are only on half of the time.

To fix this, I will be installing a bridge rectifier I got from radio shack for about $1.25

Also, once you install a bridge rectifier on one set of lights, any strands you connect to the end of it will be rectified as well. It is important to get a high rated rectifier if you plan on daisy chaining many of these lights together. The one I used was rated up to 8 amps.

Music: Hektikmusic - Holiday Storm.

[nevellgreenough]

This method may not work on longer 120V strings because 1/2 the string may be wired for positive polarity and the other half for negative polarity. Sometimes the two halves are interleaved. Fixing this will need massive rewiring.

[jetjazz]

"flicker a little bit".... more like flicker so much I turn into the Hulk and throw the Christmas tree through the window.

[timkopiczko]

Don't forget to add a current limiting resistor.  You may cause issue or blow out.  In my case I experienced funky off/on operation due to breakdown (heat).  Take a current reading and add a resistor to equal your initial (pre modification) reading.  Add a small (160V) cap for true flicker free operation.

[GCS]

Have a 20meter led string lights and the controller broke plugged them directly to the power source but I had the flickering issue but after doing this it eliminated the problem and also it seems brighter than it was when directly connected to the power source.

[christopherpahl]

I did the same thing and wow is it an upgrade. The quality of light is so much better and it is a lot brighter. I even made 120v DC plugs as well so I can plug normal household thinks into it. I wonder if it will increase the life of my hair drier, no I better not.

[dogshare]

Will this rectifier possible to handle 120 pcs with 100 led each using single rectifier?

[edb]

Zoranan, thanks for the Video.
I ordered a bridge rectifier NTE5300, like you but they sent NTE5311 (silicon bridge rectifier). At any rate, I made the connections with alligator cables and it tripped the breaker. Any ideas?
Thanks.

[mickricksbsc]

This fixed the flickering in our Walmart $20 lights we bought a few years ago. But one of the strings went dim during the holiday and when I checked them out, the first diode in the string was dead. And on checking the socket, it is only outputting 26v. Which is strange as it is a standard mains connection. Any ideas anyone?

[mickricksbsc]

I bought six sets of 25 clear, warm white C9 lights from Walmart @ $19.99 a set. At that price they had to be a bargain, right? Well I just tested them earlier and they are like Studio 54 on a Friday night. So I watched this and have ordered some bridge rectifiers. Hopefully they'll do the trick

[davidshank]

Engaging video and an interesting unconventional solution. Very enjoyable to watch.

[kennmossman]

Does that stop ALL the flickering? Don't think so. You need to put an elect cap across the DC. BTW is that like a 3A bridge....overkill???

[doughairrell]

Quick tip- If your cheap xmas lights have an electrical plug that can be rotated 180 degrees and still fit in the slots (same size on both electrical plug-in fingers), try unplugging, rotate the plug and plug back in. Worked for me.

[jpmoench]

is there and product that changes the AC to DC at the receptacle, or increase the frequency so flicker is not perceivable?

[Jerry-ccve]

Sir, I was wondering if it was 220 volts and have 100 leds. What happened if one led burn out - does that make the 99 other get too much volts and will burn also? since it is in series arrangement. What do I need to make it more safe? tx.

[pmgodfrey]

May not work on every LED set. Some have half the LED's on with one side of the waveform, then off and the other half goes on. So converting AC to DC will just light half the strand in some cases. It's easily fixed, but sometimes is more trouble than it's worth. The flicker bothers me to no end. Same thing with watching old DLP televisions with the color wheel and some plasma displays during rapid transitions (rainbow effect). Gives me headaches.

[km]

Why isn’t this part of the plug when I buy them? It wouldn’t cause any problems downstream, was there some odd harmonic problem utilities found? If they can deal with tons of AC units they can install some filter caps.

[gregbrown]

I can't think of why it wouldn't work, but if I were to wire up this bridge rectifier to a male and female connector (creating a separate, removable device) so that it could be used in-line without modifying the string itself (perhaps to use on other sets) would there be any problem?

[kittyfanatic]

No heatsink for the BR?
How does it work for end to end strings?
I'm thinking with a heatsink on the BR and an ac cord and outlet plug you could connect the strings end to end for indoor or outdoor use without molesting the plugs and simply keep the box inside or in something that protects it (ie:lamppost base) and run the strings end to end from there. May need a heavier rectifier but what do you think?

This is great information thanks. Probably helps add life to the leds as well.

[liberalpoet]

Dude! This is soooo Helpful! Now I'm not sure if it will work for other LED lights but it's worth a try! Great and informative! Thanks!

BTW, I searched for days, trying to find a solution to my strobing lights, that show up in videos, then finally found yours by luck. (I never searched rectify).

I would suggest that you add words like "Strobe, stroboscopic, Flicker, eliminate pulsing, bad LED's, Camera LED flicker, Video LED strobing, etc. in the "Tag" search box. Because a lot of people that make film and video, are trying to convert to using LED's as a source light (like me) and it's also an old trick to have Christmas lights in the background for depth and Bokeh... But since most of these lights are LED's now... This information would be super helpful, and I'm sure you'll get even a LOT more views! Best!

[Nikita_Brus]

Quick Question. Does this method eliminate flicker when your camera's shutter speed is dialed to 1/48th of a second?