GBGB, LD-51 dual cell XHP35 Boost Driver, Great Price!

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Jerommel's picture
Last seen: 1 year 8 months ago
Joined: 01/04/2014 - 13:18
Posts: 6380
Location: the Hague, Netherlands

LightRider wrote:
WTF wrote:
I learned a little about this stuff a long time ago and seem to have forgotten most of it. You’re right about series/ paralleling inductors but for some misguided reason I think they get paralled to double the stored energy in this application.Saturating the inductor is bad news, probably safer just to find a bigger one, don’t go too big because you don’t know how it will affect everything else in the circuit.

The old controllers had slower switching frequencies and needed bigger inductors. The newer stuff has higher switching frequencies, smaller inductors but the core needs to be higher quality. As the frequency goes up managing eddy currents gets harder. Whenever I see a torroid I wonder how good is the core.

I was told the light blue ones with one dark blue side are the best for buck and boost conversion.
If you try one keep checking it for heat, you’ll know in a couple minutes if its ok.

I’ve been wanting to review this inductor stuff as well. So can you unwind any conductor and rewind with a bigger wire and the same number of turns?

I’m not sure, but i think it’s probably the number of turns AND the core material that matters.
Best would be to buy a LCR meter (for inductors, capacitors and resistors) and measure the result.
You can get cheap ones on AliExpress (just a PCB with a display), they’re accurate enough.
Last seen: 1 week 14 hours ago
Joined: 01/12/2022 - 14:56
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OK this is a super old thread so apologies for adding to it, but it looks like the LD51 board has evolved since the resistor hack was worked out…

I’m interested in trying to push a bit more from the board as was posted earlier, but I can’t quite make out what’s what on the new board.

If anyone wants to take a guess as a good place to start adding resistors to I’d appreciate it.


FWIW I felt daring and shorted R018 and didn’t see a change in output.