Flicker free LED lights
Yesterday I learned that while you can still, from a few sources, buy regular old incandescent bulbs in EU countries, their import is banned since February 2016. So they really sell the rest now and it's declining each day. And you can't import them anymore. Not even from China. I advise anyone who lives in an EU country to stockpile now before it's too late.
Please do write your congressmen, and the president stating your desire to see the EISA restrictions removed. Ask them to reconsider The BULB Act (H.R. 2417) which removes these restrictions. This is a rare chance to get this done given the current administration we have.
KM After further investigation I found out that FfT bulbs are indeed flicker free. BUT these bulbs are very sensitive to the input electricity. If the input is not perfect these will flicker and will give you a headache like you mentioned.
You should test that "Flicker free technically" bulb you bought with a UPS(disconnected from the mains to generate perfect input for the bulb, otherwise you will get the same input as the mains) or with a Voltage Regulator.
Let me know this works.
PuffyCloud I'd imagine using a pure sine wave double conversion UPS would help as well,, vs one that just filters the input electricity and switches to battery during an outage.
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JTL I was investigating a UPS a while back because we had very bad voltage fluctuations at our house and I wanted to protect sensitive electronics. All of the Cyperpower units and all of the cheaper APC units either a) no pure sine wave output or b) not fast enough response time (4-8 ms in Cyperpower units to switch to battery power, but pro APC units had very good 2ms response, which is enough)
So if you want to regulate voltage through an APC you have to go for some of the more expensive and not entry level APC units.
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degen I'm looking into this for the server rack in my garage
A bit pricey, but better than other options. The rackmount form factor increases the price just because it's for "business" use
http://excessups.ca/apc-smart-ups-rt-2000-surta2000rmxl2u-refurbished
Apparently the UPS has 0 ms transfer time
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Has anyone tested these bulbs?
https://www.amazon.com/dp/B00MNU0BSQCustomer care claims: "Our Finally light bulbs do not flicker. We have found customers who are sensitive to flicker and blue light really enjoy our light bulbs.".
AGI 99% of LED bulbs I've seen are crappy.
https://techsensitive.com/ has good reviews on the few that work but he is also Canadian so they would be 120v input
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PuffyCloud It sounds like you measured the "FfT" bulbs you tried. Did you measure any frequencies, and what exactly do you mean by "they go dark"? Like, really no light anymore? This might be very important, please reply.
I just measured my headache bulb which I still own with my oscilloscope setup. It is the "GreenAndCo TM-A19-6W-E27-W". I did not find frequencies other than 50 Hz and 100 Hz apart from very small fluctuations around 60 kHz. The latter are so small they only truly appear in the spectrum analysis (and only in AC mode). And the visible 100 Hz ripple appears to be very minor, too. At most 5 mV out of 600 mV total amplitude. That is well below 1 % difference. Can such small differences really cause headaches?
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These Chinese Corn LED bulbs do flicker (pencil test), but they do not cause any eye strain for me.
Their parameters:
Voltage: 220V
LED type: SMD 5050 (square).
Color: warm white.
Image:
The bulbs which DO CAUSE eye strain to me immediately:
Brand: Philips
Voltage: 220V
MPN: 9290011717A (9W, warm white)
MPN: 9290011718A (6W, warm white)
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So I took my Fauser LiFli flicker detection device and went to a local IKEA store to measure the currently available bulbs in their lighting section. The vast majority of their lamps and bulbs flicker. However, some of them showed no sign of flicker on the device, which means the flicker must be below 1.5%*. So I bought those bulbs and took them home, measuring them with my oscilloscope setup. I tried to carefully measure even slightest fluctuations. Here are the results:
- IKEA LUNNOM LED 600lm 5.5W 2200K E27 [703.545.64]: ~30% 100 Hz flicker that goes down to steady 0.41% 100 Hz flicker within ~7 seconds, no measurable high frequencies
- IKEA LUNNOM LED 100lm 1W 2200K E27 [003.821.84]: borderline measurable 0.03% 50/100 Hz flicker (the 50 Hz part may be photodiode circuit noise), no measurable high frequencies
- IKEA LEDARE LED 600lm 7W 2700K E27 [903.887.75]: 1.24% 100 Hz flicker, decreasing over time down to 0.29% 100 Hz flicker after some minutes, 0.33% 80-100 (varying) kHz DC ripple
- IKEA LEDARE LED LED1719R6 400lm 5.3W 2700K E14 [503.658.27]: instant 0.18% 100 Hz flicker, no measurable high frequencies (total brightness decreases a little over time)
- IKEA LUNNOM LED LED1641C2 200lm 2W 2200K E14 [403.545.32]: instant 0.06% 100 Hz flicker, no measurable high frequencies
Those bulbs have E14 and E27 sockets. They are compatible with 50/60 Hz 220/240V~. They seem to be available in other EU countries' IKEA stores, too. Maybe for those countries who have a different power network, they share the same flicker characteristics world-wide.
I must see over time how those bulbs work for me. What's great so far is they don't make me feel sick after some minutes like other LED bulbs did. Plus currently I'm under the impression that truly flicker-free LEDs don't exist as long as they are powered by AC.
* (I adjusted the device to show flicker percentage as (A-B)/A, where "A-B" is the difference between highest and lowest amplitude, and A is highest amplitude. My oscilloscope results are also calculated with this method.)
Edit: Almost forgot, I took a photo of a GU10 LED that I didn't buy but was "flicker-free", too:
Those bulbs that I bought, they still hurt. I can't use them a whole evening without pretty severe eye strain. As it is hard to believe that 0.03% of flicker would cause anyone any trouble, maybe the flicker theory has reached a dead end. My incandescents, which flicker at 20-35% are much more comfortable.
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In my backyard there are some street lights for everyone to use when it's dark, so people find their garage and car. I found whenever they used the lights, which turn off automatically after 5 minutes, I O eye strain that persist for 1 hour+. The light that was coming into my room was very subtle. However, I made sure to buy light-blocking roller blinds and curtains to minimize the light.
Edit: A long text got destroyed because my phone's battery died. And I typed it on the phone. I'm not typing it again. Short form: suddenly eye strain in a dark room with everything closed, windows behind me, looking at the bright (known-good) phone screen. I look outside and realize someone has turned on the streetlights. A small reflection on the wall and ceiling caused the eyestrain. The lights flicker at 100 Hz. The reflections are very faint plus not remotely visible when you look at a bright screen.
I'm telling you this to raise awareness that even slightest changes could cause eyestrain. FRC, temporal dithering, the LED bulbs I tried, their flicker is extremely low. Yet they cause trouble. I blocked blue light on my bulbs and verified it was truly blocked with a spectrometer. Blue light is not their issue. Only the flicker remains. And even very low percentages of flicker seem to cause eye strain.