Author Topic: Poorly designed LED modules  (Read 587 times)

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dnix71

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Poorly designed LED modules
« on: December 13, 2016, 07:20:58 PM »
http://hackaday.com/2015/09/14/why-100-watt-ebay-leds-are-not-your-friends/

The video is over a year old, but the testing and math are simple.

It shows why you need a current limit driver for each LED in a cluster, but if you do this, you will be forced to discard many LEDs as they were originally dumpster-dived rejects that shouldn't have been sold in the first place.

It also shows why making high efficiency LED lighting that meets US federal standards is difficult and expensive. To be efficient, all have to be driven separately, but that raises the price, as many have defects that only become visible by testing them first.

David HK

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Re: Poorly designed LED modules
« Reply #1 on: December 14, 2016, 04:14:28 AM »
A very interesting documentary to make one think.

Thanks Dnix71.

Dave

Bruce S

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Re: Poorly designed LED modules
« Reply #2 on: December 14, 2016, 06:47:48 AM »
I liked his sense of humor too.
Thanks for sharing.

Makes me feel better about building my own sets, except of course when Rich Hagen builds them his are still years better than mine.

Cheers
Bruce S
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electrondady1

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Re: Poorly designed LED modules
« Reply #3 on: December 14, 2016, 06:56:50 AM »
what would you suggest as a current limit driver?

dnix71

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Re: Poorly designed LED modules
« Reply #4 on: December 14, 2016, 01:25:45 PM »
electrondady1 Some easy and cheap, some not so easy and cheap.
http://electronics.stackexchange.com/questions/55823/how-can-i-efficiently-drive-an-led

The one at the bottom using a JFET requires testing each JFET to see how much it leaks.

Bruce S

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Re: Poorly designed LED modules
« Reply #5 on: December 14, 2016, 01:31:16 PM »
dnix71;
Those will require some reading for me.
I come from the school of "commanda" . The write up still stands as my go to. Rich's 12Vdc units (the ones still working in Philippines ) are by far some of the hardest working units. TONs ahead of what I see in the bargain bins.

Thanks for the link.

Cheers
Bruce S
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