Could you please fix one glaring mistake on your cct.
L1 connects to the center-tap of T1, with the diodes and snubber coming off the ends.
GGoodrum wrote:Or, you could just use one of Richard's current limiter boards: http://endless-sphere.com/forums/viewtopic.php?f=31&t=21768&start=0.
I just finished testing an expanded version of this little widget, which adds a end-of-charge low current shutoff function, and logic to keep cells from exceeding the HVC set point. This basically turns this into a full-fledged charge controller.
El_Steak wrote:Have you tested it to charge your 24s Lipo pack with your 4 x S-350-24 meanwells in series? (I have the same setup)
Richard was suggesting that with such a setup 2 current limiters might be required.
fechter wrote:OK, back at the lab, I did some work on the S-350-24. Stock output was about 27.5v at maximum adjustment. This is just a little too low to work for 8s worth of LiFePO4 or a pair of 12v SLA. Lowering the value of R25 increased the max voltage up to the limit set by ZD1. Since I'm lazy, I was able to mod the board without removing it, which is a pain. Using a very thin flush cutting snipper, I was able to snip one side of ZD1 with the board in place.
Since I want lower the value of R25, I can just add another resistor across the one that's there from the top.
I used a 10K and bent the legs to hook onto R25. With 10K across R25, the maximum voltage increased to around 32v, which is just right for me.
After hooking it on, I bent the hooks up to hold it in place while I soldered it. Here's after soldering:
Since one side of R25 is the voltage sense, the added resistor makes a handy spot to attach the voltage sense wire.
I did some testing with a big resistor. Sorry I can't remember who sent that one to me, I think it was Methods, but it's a honker. And it gets really really hot!
Limiting action seemed to work perfect within the conditions I was able to set up.
So it is possible to do pretty much everything without lifting the board out.
Do we need to do anything to ZD1 or R25 if we are not trying to raise the upper voltage limit? Or can we just attach the sense wire to R25?
GGoodrum wrote:As I said above, it will work with the HVC signal off a v2.x board. On those boards the HVC line is called "ANY SHUNT ACTIVE".
DaveAK wrote: It's a genuine Meanwell S-100F-24, but what I want to know is how can I tell if it will work as a CC/CV charger? It's somewhat different than the S-350-24, (no fan for a start), and I'd need to know what mods to make. I'd like to get it up to 30V but would probably use one of Richard's current limiter boards to be able to run it from 0.25A up to a maximum of 3A.
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