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I have two 150 Watt LED Panels bought from aliexpress directly connected to my Power socket. Obviously they flicker 50 times a second due to alternating current. What's the simplest way to get rid of the flicker to create smooth and constant light?

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  • As I understand it if you have LEDs connected to 50 Hz mains power, then the lights are powered at 100 Hz because the LED is powered equally on both halves of the sine wave. This should be well above the flicker fusion frequency for the average person. Commented Jan 26 at 13:24
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    While there are many questions about LEDs flickering, do not think there are any or many about flickering at 50hz(or 60hz). Leads me to think the lights are defective or not made for 50hz or not wired correctly.
    – crip659
    Commented Jan 26 at 14:16
  • Seems unlikely that there is not an ac-to-dc conversion in there, likely with a dc-dc section operating at kilohertz or higher. Although with Aliexpress type places…
    – Jon Custer
    Commented Jan 26 at 15:23
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    I stopped reading at, "bought from aliexpress". 99.9999% sure that's the problem right there.
    – FreeMan
    Commented Jan 26 at 15:53

1 Answer 1

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You're not going to like this solution:

Buy Better Quality Lights

There are a bunch of different ways to convert 120V 60 Hz or 240V 50 Hz power to low-voltage DC to power LEDs. Some of those methods are subject to the AC frequency (either 1x or 2x) appearing in the output, some are not. Some of those methods are much more efficient than others. Some produce much more heat (which is essentially the inverse of efficiency) than others. Some are properly designed and tested for installation on a 120V-240V AC power system, some are not. I suspect your particular lights fail in all of these ways:

  • AC frequency present in output
  • Relatively inefficient (by LED standards - likely still more efficient than equivalent incandescent lighting)
  • Excess heat production, which can be a problem in some installations
  • Poor safety design, which is a real problem if anything goes wrong

Typical things of this production type (whether lights or any other electrical equipment) have lots of symbols thrown on them to make you think they are great:

  • TM - Trademark - legal but nothing to do with safety
  • CE - Conformité Européenne - European safety mark, but "self certified" so means very little with mailorder items, particularly from certain parts of the world
  • FCC - Federal Communications Commission - generally a certification regarding radio frequency interference, but nothing to do with safety
  • IP + a number - Rating of protection from water and other damage. Nominally related to safety in some situations, but nothing to do with basic product safety

In the United States, the marks to look for are generally UL and ETL. These are specific organizations that certify that equipment is designed and/or tested properly for safety. In other countries (50 Hz. lands) there will be other symbols or ways to determine that an item has been properly designed and/or tested. If you are not sure what to look for, the safe thing (but admittedly often more expensive) is to go to a reputable bricks and mortar store, as in many places there is sufficient local laws and law enforcement to make sure those stores only sell the right stuff. With mail-order there are a number of legal (and sometimes not so legal, but not enforced) ways that a vendor can ship you things that are not safe with no repercussions other than dealing with occasional returns.


A quick search on aliexpress, the vendor noted in the original post, finds 2 x 150W LED panels for $0.99, on sale from a regular price of $11.56. Even at $11.56 for a single panel it would be hard to include a properly designed power supply. So it is no surprise, at all, to see such an item with every possible corner cut in order to get the stuff out the door at the absolute lowest possible price. And to be honest, if you slap these panels on a warehouse in certain parts of the world, nobody will care about safety rules, import regulations, etc. and a little flicker won't matter much. But most definitely caveat emptor.

To get an idea of just some of the problems with these types of things, take a look at Clive's teardown of a "100W" panel.

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  • My question was how to get rid of alternating current in the LEDs. I'm not interested in your rant and your opinions. What a ridiculous way to waste peoples time.
    – AzulShiva
    Commented Jan 30 at 15:40
  • Well, meanwhile nobody else has come up with a better answer. And I did state right at the very top "You're not going to like this solution". I stand by my answer though because I am cautiously optimistic that it will help other people to buy/install only properly designed/listed/certified (UL, ETL, etc.) equipment of this sort. If you want a fix that doesn't involve new lights, it is probably to install an AC-DC converter and hope that the lights will work with it - if they work with it then the flicker will be gone. If they don't work then you could get a dose of the magic smoke. Commented Jan 30 at 15:58
  • Apparently I can wire 4 SKBPC5016 Bridge rectifiers in Series before the lamp which I can get off Aliexpress for 2$ each. If it works I will post an answer here to get more downvotes. Anyway, you do realise those lights are just a bunch of LED strips wired in parallel for 220V? I could just disassemble the unit, bypass 1/5th of the lights, and use an old 48V DC Power supply. If one of the LED's break, no more current flows through the circuit. There will not be any smoke and I will only need to replace/bypass 1 LED in the lamp,
    – AzulShiva
    Commented Feb 10 at 14:51

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