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EOLED 10w Flood Light
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My 10w LED floodlights has died! It comes on at full brightness for a few seconds then dims down to this level and stays like that. It's been run dusk till dawn for about 2 years. It's a cheepo eBay special, I only paid £7 for it delivered, this was quite a while ago when these cost around £25 normally. Surprisingly this was properly sealed, had a long copper core flex attached and was earthed! But despite all of this, a cheap B&Q 23w CFL at the other end of the house has outlasted it...
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As for the light, its got nothing to do with the K temp. You could use a Fluorescent or Mercury lamp with same temp and it wouldn't look anything bad
If the load on the driver output is low (and for a constant current driver this means, low voltage drop), the power going through is regulated accordingly. When the load is too low (out of spec), a point is reached when the secondary for powering the chip can't maintained the capacitor charged either. At this point it will shut down, and only the initial-startup voltage divider remains to charge up the capacitor. This takes about one second or less
When this happens every time, there is the disco....
The reason why the load voltage gets suddenly low, is as diodes on the COB are shorting out, its forward voltage falls. For example, take one die with 10Sx5P diodes. One shorted. Immediately virtually all the current for the entire COB will go through that row of 10 diodes, and more of them will start shorting. After only a few working diodes remained, the voltage is low enough for the driver to start the disco. As it does, the COB does only get power intermittently, so it heats much less, so further degradation freezes