Anybody ever notice LED lights flickering rapidly?

hank

Just bought a 750 lumens shop-light on a stand for my garage. Replaces an old halogen of similar brightness that went thru bulbs rapidly and could never be trusted to work when needed. Very hot as well. The new light has two square lenses about 7x7 inches whose surface resembles a “checkerboard” in the way laid out. Apparently dozens of very small lights working together. Well, the second time I used the new light (Husky brand from HD) I noticed a weird flickering.Probably several dozen times a second. Most noticeable when looking right at the light. Less noticeable when looking at the area illuminated.

Just curious. The thing cost over $100 so I’m a little bit concerned.

I’ve used other types of LEDs for years and never noticed this. Found an article which seems to confirm what I’m noticing.

http://www.ledlights.org/FAQ/Why-Do-LED-Lights-Flicker.html#:~:text=It is a fact that all LED lights,as a half wave, also called non-rectified light.

catch22

Dirty AC perhaps. Your unit may not have sufficient"electronic filtering" which would attempt to remove "noise" in the AC power source.
Is this now a constant condition? Being flickers, no matter when the unit is powered on.
A few things you could consider:
--- were there electric motors that were operating in the house when you noticed this problem? Electric motors can induce "noise" into a house system.
--- what other devices share the same circuit in the house to which the lamp is plugged into?
--- any nearby fluorescent lamps operating at the time of the problem? Bad starters and/or weak tubes (pulsing).
--- does the problem remain, no matter which outlet, in the house, you plug in the lamp?

OR, you have special powers you were not aware of.................which may also provide an investing edge.

Let us know the outcomes.

hank

Hey Catch / After it had been on 10-20 minutes today the issue seemed to clear up. I suspect you’re correct. The garage has its own 240 / 120 volt power supply. Other things operating? Yes, I’ve an old plasma TV out there which was operating and a blue “bug light” hanging from the rafters to destroy unwanted flying pests. There’s also an old refrigerator, but was running on its own dedicated circuit.

Old_Joe

With respect to "dedicated circuits", that likely means a circuit that's on a discreet fuse or circuit breaker . A circuit breaker or fuse affords absolutely no isolation against circuit noise- if noise is being introduced by any other circuit feeding from that breaker or fuse panel, it can easily migrate across all of the circuits in that panel.

Even a panel itself does not provide noise isolation. If two separate panels are fed from a common power source, noise may easily spread across the whole shebang. Noise isolation would probably occur only if the panels were each fed from a different power transformer.

hank

Wow! Hopefully I’ll learn to put up with the light. Yes, the garage, while detached from the house and having its own breaker box, is fed from the same “main” outdoor power panel mounted on the side of the house. HD actually had a brighter 1,000 lumens stand light for $20 less. But the one I got takes less space when not in use. The twin lamps fold-up (clam shell fashion) really nice. If it is noise from another device, I’m inclined to think it’s the bug light. Next time I notice flickering I’ll unplug that to see if it helps.

If anyone’s shopping for one of these Lowes was much more expensive light for light than HD.

PS - Thought it would be interesting to discuss something as far removed from politics as possible..

Old_Joe

@ hank- BTW- your "Why-Do-LED-Lights-Flicker" link is a good summary for LED lighting issues.

catch22

hank
Still good with proper operation of the LED array?

hank

catch22 said:

hank
Still good with proper operation of the LED array?

Sorry Catch. After 10-20 minutes yesterday morning the light seemed normal or “almost” normal. Limited use. I’ve been so busy running the logsplitter outdoors / hauling / stacking I haven’t had an opportunity to use it again. Yesterday morning I was stacking a bit in a corner of the garage which led to turning the light on. But 80% of the wood gets stacked outdoors.

Suspect the bug light that I leave constantly on may be the “noise”. Will try unplugging it some future time. Than again … the electric motor on the refrigerator might be the culprit. I’d tried the light out the day before and didn’t notice the flickering. So the motor might be the cause.

Thanks for asking. I may post here at some later day when I get back using it inside.

Old_Joe

In thinking about this whole thing, it seems to me that a refrigerator is unlikely to generate significant electrical noise. Noise typically is generated by the rapid switching on/ off of an electrical load. This can indeed occur in some electric motors, but not the type used in refrigerators. Refrigerator motors might generate a bit of noise when they start, but not while running.

I'd be inclined to wonder about the type of circuitry used within the LED light fixture itself, as mentioned in the OP link.

hank

Thanks OJ. My first impression was it was perhaps a unique feature of that type of LED light. Never had one with the grid pattern on the lamp surface before. Probably a couple dozen little squares on the face of each lamp. It took a lot of concentration to pick up the flicker - so rapid were the spikes in brightness. Interesting too is that it gets very warm after an hour’s use. Almost too hot to touch. Any other LED I’ve seen stayed cool. 750 lumens is a nice help. But not as bright as the duel 500 watt halogens it’s replacing. But hot! Those things capable of some serious burns!

That grid pattern is new to me. But I was at a construction contractor’s place a few days ago and noticed that weird looking grid on the square headlights of a couple of his dump trucks. New to me anyways! Must be a way to increase brightness.

Old_Joe

When I've taken apart a number of failed LEds just to see what was in there I saw that an individual LED was typically a small square, maybe 3 mm square. Perhaps that's what you're seeing in that grid pattern- a number of those little squares arranged in a grid.

Speaking of heat, it's my belief that the heat buildup in many LEDs is a major factor in their premature failure. Some LEDs seem to last almost forever, others surely don't live up to the "long-life" rating.

hank

Thought I’d correct my earlier info. Actually the light is 7,000 lumens (not 750). Appears to pull 80 watts (12% of what the old halogens did) Found identical lamp at Amazon, but with a Stanley branded name and yellow rather than red colors.

Sorry for earlier misinformation. Running around this summer like the proverbial “chicken with his head cut off”. In northern Michigan we manage to squeeze a year’s worth of outdoor work into 3 or 4 months before turns cold again.