I've had some leds in my work area for light the past months and just recently one set will start to flicker apparently randomly for random intervals < 1.5s
The led driver is a cheap unit off ebay meant for 350ma constant current switching style, and the led setup is 3 1w leds in series
what could cause the driver to fail like this? Maybe summer heat? Or is this just ebay crap failing?
I would look for bad soldered connections on the driver board.
It could be heat related. That shouldn't be too hard to test... Is it worse on hotter days (or during the day) or after it's been running awhile and has warmed-up? Maybe you can set on an (insulated) ice pack to see if it works better when cool. The problem is... Knowing that it's heat related doesn't solve the problem.
Is this a driver chip,or a power supply module? If it's a chip, it might need heatsinking (or more heatsinking) to meet the full 350mA rating. If it's a module, it should work as specified.
If banging or mechanically shocking the unit causes it to flicker, it's a bad solder joint or bad connection. Most electronic failures are caused by bad/failed connectors/connections (assuming the design is good, and the device/product was used as intended, etc.).
You said one set flickers... Is it easy to swap the LED sets & drivers around to see if its the driver or "something else"?
Or is this just ebay crap failing?
Could be... You have to wonder why it's being sold on eBay, rather than through the normal electronic-parts distribution channels.
dc42:
I would look for bad soldered connections on the driver board.
personally, I'd look at the physical connections on the led's themselves
Star-board connections can look good but physically be dry-joint.
ALSO, do you have heat-sinks as well as star-boards? heat kills led's
It does get quite warm, almost too warm, it is soldered well tho, I preheat the board so it actually soldered well
im gonna check its own solder joints but its weird, it'll be full power, off or dim all randomly
Traffic Lights in the US (well Southern California at least) are LED exclusively now and If you are lucky enough to get a defective one (one with flickering lights in some of the "pixels") you will find one current controller and a LOT of series parallel led's. I have a big (14"+ Green one on the floor next to me) The flickering of individual pixels always affects more than one LED... A series chain of led's with one led defective in each set of flickering led's. This might very well be the issue here. I found my bad led's by briefly shorting each Led in a flickering string. in my case the minor 20 -50 ma change in a string wasn't enough to endanger anything else, in your case I would attempt repairs by substituting a known good and identical device. Although if you are driving the chain of LED's from a CC power supply it shouldn't make a difference LED's or not as it is a constant current not a constant voltage that is the power source. A CC gen will adjust it's voltage to keep the current constant unlike CV supply that adjust the current to keep the voltage constant. The defective led will show large voltage jumps when it's internal connections become intermittent, the good ones will do just the opposite, they will drop in voltage during failure/flickering.
Doc
That makes sense, maybe that's why it takes a few seconds unril it starts, as the led warms up
I put a multimeter on it and normally the string takes 10.5 v but when it was flickering id get readings of over 11 and sometimes 7
Must be an led internally failing
That's cool didn't know leds can fail intermittently, just jumped out each led until it stopped flickering, now I know which one to replace
thx again
Very Glad my Small advice was of help.
Doc