campus189
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I wouldn't recommend that junk converter you found on Ebay. Most of the cheap but decent ones will claim a 1A capacity.
Would it be more efficient to just replace the resistors rather than buying an adapter? I mean power waste.
Would it be more efficient to just replace the resistors rather than buying an adapter? I mean power waste.
it will run on 5V. The extra 0.1V or 0.2V won't hurt anything if these resistors are put in place of the existing 1.5Ω resistor. The LED current may go as high as 22mA each at 5.2V but that won't be a problem.To convert the panel to operation on 5V, change the resistor to two 5.1Ω 5% ½W resistors in parallel. This will slightly reduce the LED current to 19.6mA each.
If you follow the instruction in post #8 it will run on 5V. The extra 0.1V or 0.2V won't hurt anything if these resistors are put in place of the existing 1.5Ω resistor. The LED current may go as high as 22mA each at 5.2V but that won't be a problem.
I deleted a previous post and some edits on this one as I just realized your picture of the new DC-DC converter showed the 7805 for size comparison only. At first I thought it was part of the unit.
Those converters have a nice big inductor. That's a good sign and a nice find at $2.50. I like how the USB connector is even crooked as if to say "I was made in China right down the road from where your Ningbo light was made."
I'd be interested in seeing a good close up photo of both sides of the board. I'm also curious about efficiency when completed.
It's your choice whether to keep, edit or delete your posts. I don't mind one way or the other.
Take a look at this short, fun video on soldering.
YouTube - How and WHY to Solder Correctly
It's the best soldering instruction I've seen in less than 7 minutes. No one will make fun of your soldering if it's good.
Jameco Electronics is often good for small orders. I'm assuming you're having difficulty sourcing the 5.1Ω resistors.
All Electronics (a surplus store with a good reputation) has the 5.1's: .
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