LED versus T5 efficiency

Gavin · 01-29-18, 06:06 PM

re comment #19
Hi Jeff,

Most CoB LEDs I have tried have a fatal flaw. There are strings of LEDs in parallel without current regulation for the separate series strings. They try to match the forward voltage, but there are changes with aging. Also if the heatsink attachment isn't perfectly smooth there can be hot spots. Either way, over time some strings hog more current, have run away and the CoB fails. I've used a bunch and not had many of them last more than a few months, a year at best.
Let me know how these work out for you over the long term. If they are good then I'd like to know the brand. Meanwhile, I'm sticking with midpower LEDs, now up to 160 lpw.

01-29-18, 06:06 PM	#21
Gavin Lurking Renovator Join Date: Jul 2010 Posts: 4 Thanks: 0 Thanked 0 Times in 0 Posts	re comment #19 Hi Jeff, Most CoB LEDs I have tried have a fatal flaw. There are strings of LEDs in parallel without current regulation for the separate series strings. They try to match the forward voltage, but there are changes with aging. Also if the heatsink attachment isn't perfectly smooth there can be hot spots. Either way, over time some strings hog more current, have run away and the CoB fails. I've used a bunch and not had many of them last more than a few months, a year at best. Let me know how these work out for you over the long term. If they are good then I'd like to know the brand. Meanwhile, I'm sticking with midpower LEDs, now up to 160 lpw.