AGI

I have checked my home lights and TV's using this application for Iphone. It is not 100% accurate but at least it is helped me to understand why my Samsung TV, Iphone XS and some LED bulbs are giving me severe eyestrain. Have tried to find similar other free app with no success.

Spectrometers are too expensive to buy (Above 1K USD). So other acceptable way to measure PWM with 10-20% accuracy for me was to purchase this device this Radex Lupin. It can be connected to laptop and show some graphs at least.

If you guys know any other acceptable ways to measure PWM flickering let us know.

  • KM replied to this.

      krr55

      Check our oscilloscope thread, the methods developed there are working very well for lighting. Make sure to read all replies, as the info is scattered across the thread.

      https://ledstrain.org/d/312-homemade-oscilloscope-to-detect-pwm-diy-guide

      @everyone: you need to understand one thing, which is not obvious and may cause disbelief: even extremely small fluctuations can cause symptoms. That is the most important thing I have discovered over time. By tiny I mean fluctuations that you cannot discover with the camera/smartphone methods. You need something more accurate. And frequencies > 20 kHz can still cause symptoms. I think both of those statements go against anything you'll currently read and hear anywhere else about lighting safety and medical knowledge, but if you already know you're sensitive to flicker it is super important that you get the right tools to check out if this level of sensitivity applies to you, too. Cameras are not the right tools. You will never capture fluctuations smaller than 1% with a camera. Not to mention the "pencil" method. Feel free to ask if you need more info.

        ensete

        Thanks, I will check if they ship overseas.

        Doubt. If a product is banned in the country where you live, is it legal to import such item from overseas? Does any of you know?

            AGI

            I can only speak to the US law regarding incandescent, it was VERY targeted, it did not ban incandescent lighting, it only banned certain bulbs that fell below the stated efficiency standards. Any incandescent bulb that meets those standards (which is plenty) is still legal, as well as bulbs in different sizes, bases, specialized bulbs, are all still legal to buy and use.

            • AGI likes this.

              I recently bought this Coffee Scale. It has a horrible built-in LED light, I get dizzy and feel almost sick after looking at it.

              There seems no way to disable the light, trying to think I can disassemble the unit to remove the LEDs somehow.

                ryans

                You should be able to with a hot air station.

                Disassemble the unit, find the LED (it will almost certainly be an SMD component) and use hot air to take it off the board. Depending on the board design the unit may work fine without it, or it may expect resistance, so use a multi meter to get the ohm rating of the LED and solder in a resistor of that measurement onto the board where the LED was

                If you are not handy with electronics, you should also be able to open the unit up, find the LED, and cover it with flat black paint. That will leave the electronics unmolested but block the light.

                  5 months later

                  KM

                  KM, could you please explain how it works? You mean according to physics it's impossive to have flicker free LED lamp?

                  p.s. I see statement on one of these companies saying:

                  incandescent 15% flicker

                  regular led 70% flicker

                  our led 0% flicker

                      I think even those bulbs would fail proper testing (with photo diode and oscilloscope). If someone does the camera test, it is no proof of "completely flicker-free". Be careful to use a term like that.

                      gety9 They'd have to explain how they measure their percentage. There are different formulas which create different percentages. Usually companies use a formula that makes their percentage look better. That company surely did that as you can see by their 15% incandescent flicker, which is very low for an incandescent. A formula that creates a high percentage would be (a-b)/a. As you can see, companies use everything they can to make their products look better. And then look at the "0% flicker" statement. It doesn't mention numbers after the floating point. One might argue it's negligible but however it may not be negligible at all not for users who are sensitive and visit this forum.

                      I have baskets full of supposedly "flicker-free" bulbs and all of them flicker either a lot (xx.0%) or a little (0.xx%), but the flicker is always measurable. So if there's yet another company making a statement like "flicker-free" or even "completely flicker-free" they better back it up with more than buzzwords.

                        Too bad waveform lighting doesn't make overhead can lights. The 4 led cans I have in my office are a bit fatiguing.

                        2 years later

                        gety9 Are there special requirements for the desk lamp to be able to power incandescent bulp?

                        No

                        however top rated review for one of the E26 desk lamps saying that incandescent bulps do no work.

                        LED's use DC power. Incandescent bulbs use AC power. You cannot power an incandescent bulb off a fixture designed for LED's. You can run an LED bulb in a fixture made for incandescent by putting the rectifier board in the bulb itself to handle the AC -> DC conversion.

                        Look for an older lamp that runs off AC, or make your own you can still buy regular old lamp cord and sockets.

                        is there any DC driven ceiling light LED?

                        All LED lights are DC

                          Incandescent bulbs are good because they have:

                          -Pro-
                          No blue light
                          Red and infrared
                          Cri 99.9% similar to sun

                          But...

                          -Cons-
                          Flickering
                          No good for Daylight (no blue)
                          No energy saver

                          My suggestion:
                          A 4000k led (corn style) for day and afternoon
                          A 2700k led (corn style) for night or an incandescent bulb
                          A 1800k led or red light led for late night.

                          dev