Repurposing Laptop/Electronics power supplies

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Jack55
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xenophon wrote:
Mon Oct 22, 2018 3:08 pm
I was able to wire a 19.5v Dell laptop power supply directly to a 2-foot Bridgelux EB Gen2 strip without issues. My meter shows a steady 19.6v. It's been stable and just slightly warm for over a week running nonstop now. I plan on getting a bunch more of these strips to run in parallel off this power supply. I will update with results.
Whoops, sorry Xenophon, missed this part. I am running the one foot variety. Makes sense now.
Hydrofood
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2’ strips at 19.5v should only pull .700mA.
I wonder what is happening to cause this higher amperage draw.
Jack55
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True but that is inline with mine - spec sheet puts the one footers around .375A for 19.6v but I am pulling .510, both are ~35% more than their data sheet estimate. I remember reading in the "DIY LED Strip Build Designs" post that they speculated that these might be capable of higher amperage.
Hydrofood
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That statement is true but it was in regards to their max, not that they could pull more amperage at a given voltage within the typical range.
I strongly suspect that the issue has to do with the power supply. If you have one, you should power the same strip with a 20v LED driver just for comparison sake.
These strips should preform as the data sheet suggests, giving they are powered by an appropriate driver. If they aren't, this would be an issue to take up with bridgelux or the supplier you ordered from.

What do you mean inline with yours?
And I thought you were running a 2' not a 1' strip?
Last edited by Hydrofood on Tue Nov 20, 2018 6:56 am, edited 3 times in total.
Hydrofood
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That statement is true but it was in regards to their max, not that they could pull more amperage at a given voltage within the typical range.
I strongly suspect that the issue has to do with the power supply. If you have one, you should power the same strip with a 20v LED driver just for comparison sake.
These strips should preform as the data sheet suggests, giving they are powered by an appropriate driver. If they aren't, this would be an issue to take up with bridgelux or the supplier you ordered from.

What do you mean inline with yours?
And I thought you were running a 2' not a 1' strip?
Jack55
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Hydrofood wrote:
Tue Nov 20, 2018 6:52 am
What do you mean inline with yours?
And I thought you were running a 2' not a 1' strip?
I just mean that we are both seeing 35% more amps going into the strips than the datasheet says, regardless of the size of the strip (.51A vs. .375A for me & .95A vs. .7A for you). I do not have a 20v although this project has be walking around my office and home checking the voltage of every power supply I can find. I am sure I will come across one someday. Maybe a Goodwill field trip....
xenophon
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I put .91 amps at 19.6v (in my 2-foot strip) down to innacuracies in the meters. I am using a clamp-on ammeter. I have a pretty good voltage meter but it's no Fluke. The ammeter seems to require a perfect middle and due to my wiring I can't quite achieve that. Does that seem like a viable explanation?

I might try an old Roomba power supply that says 22v @ 1.5amp but I am a bit afraid I will blow the strip out.
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tazztone
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the bridgelux eb gen 3 slim have 19V. perfect for used laptop chargers.
https://www.digikey.ch/en/products/deta ... 3/10279842
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