Switch mode supply mod

Update.

Rcvd my S350-48 from Sure electronics today. Removed Q5 and placed a link Collector-Emitter. Fan runs permanently now with no stupid buzzing.
(just watch the pinout, the base lead is NOT the center pin).

Wound the volts up as far as it would go (58.4 volts). Removed one of the 3 shunts. But I'm still running on the current limit in the BMS at this stage.
Further update in a few days after I mod my BMS.

AND, in case anybody missed it. The Meanwell in question has a 12 volt regulator on board which powers the fan. I pulled a flying lead from that to power the logic in my BMS and the relay which powers down the mains when the batteries are full.

Amanda
 
Meanwell_S-350-27-v1.1.png


Ahh, I see - that makes sense - and R44 no longer has significance. Don't have to do the Thermistor mod either. I bet that fan runs full-blast. FWIW - I have never experienced the buzzing sound.

In the schematic above, I wasn't able to discover the identity of the components around U2 as they were covered up my that white-glue crap. Has anyone gone to lengths and sorted the IDs out?

~KF
 
KF

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.

Amanda
 
Actually it is drawn exactly how I traced it out on the circuit board version that I have.

  • Are you suggesting that the center tap Pins are 7-10? Or is it that the labeling of the pins is incorrect?
  • Do you have the spec sheet for this device?
Images of the circuit board here here:
How-To: Meanwell 63-84V CV/CC Charger

Thanks, KF
 
commanda said:
KF

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.

Amanda

That was the mistake I was referring to...
 
Gotcha; corrected - Thanks! :)

Here ye be matey:

Meanwell_S-350-27-v1.2.png


~KF
 
Another quick update, and to cut a long story short...

I ended up having to remove 2 of the 3 current shunts to get the CC down to a reasonable level (4.8 - 4.9 amps).
So, I would suggest potential hackers to get their unit to this point, and then tweak R33 from there to dial in the current.

Amanda
 
GGoodrum said:
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.

-- Gary

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.
 
El_Steak said:
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.

No, not with four MW in series, but I think it should work. What Richard was worried about is whether pulling down on just one MW sense line was going to be enough to pull the charge voltage below the pack voltage, which cuts off the current flow, when the pack is empty. This still needs to be tested, but my gut says it should be fine, based on what I've seen so far. On a dual SP-320-24 setup, I've seen the voltage drop from 50.1V down to 42.0V, when I ground the HVC line.

I don't like working with 100V, so my 24s setups are split into two 12s3p packs. Right now, during testing, I'm just using a two MW configuration, and a dual CellLog 12-channel balancer unit, and charging/balancing each pack separately. Here's some pics:

View attachment MW Charge Controller-01.jpg
MW Charge Controller-02.jpg

The pot in the middle controls the charge current, in the initial CC phase. The pot on the right controls the end-of-charge low current shutdown set point, which is adjustable for 0-2A. The first pot, on the left, adjusts the amount of "pulldown" voltage. The LED is red initially, orange if the current limit function is active, or if the HVC line is tripping, and green in the shutdown/float mode.

As I said above, this little board completely replaces the standalone Charge Controller, both the previous v4.0x variants, and the newer relay-based versions. The HVC signal can be from either a CellLog-generated HVC "alarm" output, the HVC portion of the previous LVC/HVC boards or from either a v2.x or v4.x BMS board.

Next up, I'll be testing this with a new 12-channel CellLog CMS/Balancer unit, and then after that, with a three MW "stack" to be used with my 18s2p packs.

-- Gary
 
This is a better idea then cutting the charge current with a mosfet, simplifies the wiring greatly (and reduces the cost as well over my version) - Nice.
 
Hi
That is a nice board now, a few points, someone please test it with 4 meanwells to confirm if we need 2 or just 1 of these units to charge a 4 pack setup. Gary you touched on the fact that this board would work with most types of devices that have a HVC output, you mention the LVC/HVC boards that you discontinued and the CMS boards that is in the final stage of development, will it also work with the ver 2.x boards you ust to make and Andy is still making and selling.
For use with the the replacement LVC boards I was thinking of making a micro HVC board, this would work for charging the batteries like the HVC part of the old LVC/HVC boards did it will primarily be for LiPo's as they stay pretty well balanced, checking with a balancing charger every so often would be a good idea. You have changed the HVC value in the past so I will put in pots to law the HVC value to be altered. This will not be a pefect system but it should work.

Geoff
 
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".

Later today I will post pictures of the new 12-channel CellLog balancer i'm testing right now. This unit has an HVC output that can be used directly with this MW charge controller. Together they make up a full "CMS" that will safely charge and balance a 12s pack.

-- Gary
 
Fechter,

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?

fechter said:
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.View attachment 5

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. View attachment 4
View attachment 3

After hooking it on, I bent the hooks up to hold it in place while I soldered it. Here's after soldering:View attachment 2

Since one side of R25 is the voltage sense, the added resistor makes a handy spot to attach the voltage sense wire.View attachment 1

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.
 
number1cruncher said:
Fechter,

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?

Correct. If the stock voltage range is OK, then you just attach the wire.
 
GGoodrum said:
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".

Will it work with the stock 'Any Shunts Active' line or will we have to mod the V2.x boards to lift the 820Ω resistors next to the all shunts/any shunts diodes?
 
In theory, it should work without any mods, but there's a chance the optos might not pull down hard enough, with those resistors there. BTW, they are 20k resistors, not 820 ohms.

-- Gary
 
It's been a while since I've been online, but I have set up my four by S-350-24 charger thanks to you guys and all your help on here. But now I have another question. :D I have another project and happen to have a spare PSU that I don't even know where I got it from, or why! 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.

Here's the spec sheet if it helps. I don't know what I'm looking for.

http://www.meanwell.com/search/s-100f/s-100f-spec.pdf
 
DaveAK said:
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.

Can't tell from the spec sheet.
If you take a good pic of the board, I might be able to tell from that. Otherwise you could try overloading it and see if the current just limits or if it goes into hiccup mode.
The limiter board works with most models I've seen, but I don't know about that one. Again, a good pic would be a starting point. From that, I should be able to suggest a test.
 
I couldn't get any decent pics with my crappy camera. From the spec sheet I see that it says it does hiccup mode for both over load and over voltage protection. Over voltage kicks in at 27.6V though, and I really need to squeeze 30V out of this. I think I'll just get an S-350-27 supply off of eBay and add one of your current limiters.
 
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