Fechter's Mini Meanwell Limiter V.3

[fechter]

It sound like modding the existing circuit will be a better option. Something like the R33 mod.

Otherwise, they do make 100+A shunts (for meters) but they are huge. Other than the shunt, the rest of the circuit would be OK.
Here's a 200A shunt: http://www.allelectronics.com/make-a-store/item/SNT-200/200-AMP-SHUNT-50MV-200-AMPS/1.html



They also have a 100A version.

To use one of these monster shunts, leave the little 20A shunt out of the circuit and use a pair of wires (they can be small) from the small screws on the monster shunt to the limiter board. The terminals on the limiter board might not fit the terminals on the supply, but you can just solder a couple of wires onto the board to make the connections.

[cor]

Hey Fechter, got a opposite problem to most, where i'm wanting to limit around 130+ amps on a RSP3000/24V.
Was thinking i might need to seperate the circuit board from the shunt/s....

Hi Megacycle,
I think you have the right solution - you can't send 130A through the traces of the current limiter board.
You can still use the board if it fits on your power supply (or connect it with short wires to it)
and use an external shunt like Fechter showed.
If you build this charger fixed into your vehicle, then you may already have a shunt that you use to measure
the current that your controller draws from your batteries.
You might be able (if this shunt is accessible) to attach two wires to it, twist them together if they need to
travel some distance as they carry a low voltage through a harsh environment, and connect them to the
current limiter board at the positions where the shunt would attach. That way you do get the measurement
without adding yet another shunt. Take care of the correct polarity of the shunt - during charging the
current is opposite to the polarity during discharge...
You could also inspect your 130A power supply to see if it has a built-in current limit that you could modify
to the value you want.

[megacycle]

Thanks guys for sureing me up and the added info on the parts, appreciate. Have to re-read R33 mod info again Fech.
Cor, thats a top idea with the controller shunt, i'm just about how the shunt is connected when say the charger is using it and the controller electronics is still connected to it and not in use.
I suppose because it's not in use and it's only sense circuitry it won't interfere with fechter's current limiter

Hey if i did go with a shunt, do you think this will do for the shunt, it's a strange looking peice of kit,
salvaged two from an electronic 240V/100A ac meter.
A lot of meters are rated 0.5S, which means they don't mind running at 2x for a while.
It's strange because the shunt looks like a peice of copper,welded to the tinned bars.
If the value was different should still be ok, just need circuit component value changes
If they are no good and i cant use them for the controller, could be useful to someone on the pm.
Cheers.

[cor]

Hi Megacycle, did you measure its resistance?
(easy to do with the 4-point connection method of sending a known current, for example 10A, through it
and use a milliVolt meter to measure how much voltage drop that 10A gives, each 10mV is 1 mOhm)
I am concerned that this AC circuit part does not have a precise resistance, because in a kWh meter,
it is the field strength, not the voltage drop, that gives the meter reading.
You know, 200A 75mV shunts are common and cheap: $5.79 with free shipping:
http://www.ebay.com/itm/DC-200A-75mV-/230755898583
so if you want to be sure and have accurate readings, then it is recommended to use
a shunt appropriate for the application.
Success!

[megacycle]

It looks to be about 0.3milliohms cor, not got a lab only had 2.76A constant and a calibrated DVM, measured 0.812mV.

Looking for the latest on the R33 and associated, its like a maze of info.Type in R33 in index and get nothing.
Can anyone point me to the latest thread phew, thanks in advance.

[fechter]

The shunt gizmo from the AC meter looks like it may have a hall sensor or something like that. It might not really be a shunt.

The R33 mod on a S-350 Meanwell is going to be specific to that model. Other models may or may not be similar. You'd first need to locate the shunt (assuming it has one) in the supply, and the PWM chip, which is typically a TL494, a 14 pin device. On a S-350, one side or R33 goes to pin 15, the other side goes to the shunt. Lowering R33 lowers the current limit. On other models R33 is not likely to be called R33, so you need to trace the lines. Once "R33" has been located, the typical approach is to place a 5K trimmer pot across it (parallel) and adjust for desired current.

[whereswally606]

Firstly a big thanks to Fechter and Degull, i got my board in the post when i went back to my rents for the weekend.

Used the mouser import tool for the BOM and found that the bill was £2.36 per kit. Annoying because I need a couple of kits to start with but maybe a few more once i get the limiter sussed to work on my server supplies (ie not meanwells)

problem we have in the UK is mimimum order purchases on mouser. its £12 to play unless you put in a order of £50 or more.

So my question is this. Im willing to due the bulk order for Kits to populate the v3 limiter board in the UK but do i have a market?

Please let me know PM if you are interested.

Thanks. BTW i need interest in about 20 kits to make this worth doing.

[megacycle]

Thanks fechter will take the lid of and look
The shunt thingame, not sure as there is no component there's only a peice of what looks like copper and the blue and white wires are welded either side.

[fechter]

Thanks fechter will take the lid of and look
The shunt thingame, not sure as there is no component there's only a peice of what looks like copper and the blue and white wires are welded either side.

Try posting a pic of it.
Some of them have multiple shunt elements. It will be directly connected to the negative output terminal in most cases.

[fechter]

Used the mouser import tool for the BOM and found that the bill was £2.36 per kit. Annoying because I need a couple of kits to start with but maybe a few more once i get the limiter sussed to work on my server supplies (ie not meanwells)

problem we have in the UK is mimimum order purchases on mouser. its £12 to play unless you put in a order of £50 or more.

You should be able to source all the parts from a UK distributor. I'm not sure what you have there. Farnell comes to mind. It would take a little research to find their equivalent part numbers.

[whereswally606]

we have farnell and RS components. i tried both by internet searches and some of the components have min order requirements ie come in lots of 50, which means it might cost twice as much as getting stuff through mouser and having surplus bits i dont need. but I take your point. So in short Im still looking for uk/europeans who need kits made up. I have one from Henk in switzerland already so only another 19 and ill stick the order in.

[megacycle]

A closer look at that thing.

IMGP0043.JPG (99.76 KiB) Viewed 411 times

Appears to be just copper with the wires for mV, there's a red one that's welded too, think it's a a.c. volts pick up.

The lid came of the RSP3000.
Lid revolves on the only screw thats hidden under the label.Do'nt want to go there, warranty.
Got to watch the control card, that stands up off a board connector to full height of case, led from it goes thru back plane, would'nt want to knock it flimsy as.

[fechter]

Wow, that thing is a monster.

Is there an instruction sheet for it?

One of the two pots on the top of the board might possibly be to adjust the current. That would be pretty handy if so.

[ambroseliao]

Firstly a big thanks to Fechter and Degull, i got my board in the post when i went back to my rents for the weekend.

Used the mouser import tool for the BOM and found that the bill was £2.36 per kit. Annoying because I need a couple of kits to start with but maybe a few more once i get the limiter sussed to work on my server supplies (ie not meanwells)

problem we have in the UK is mimimum order purchases on mouser. its £12 to play unless you put in a order of £50 or more.

So my question is this. Im willing to due the bulk order for Kits to populate the v3 limiter board in the UK but do i have a market?

Please let me know PM if you are interested.

Thanks. BTW i need interest in about 20 kits to make this worth doing.

I wish someone would do this for the USA. I've tried using the BOM tool at Mouser and am just befuddled. I put in the list as stated at the beginning of this thread and only half the items show up and there's no way to manually add them, it seems...

Can someone point me the way on how to import a BOM? Better yet, can someone use the Excel template they provide configure and save the resultant files as separate .XLS or .CSV files for each voltage and current range? I would greatly appreciate it! Thanks for helping a BOM challenged ebiker!

Ambrose

[whereswally606]

Here you go, I had issues at first so i made this excel sheet. still need 19 more euro/UK buyers for my £50 group buy

v3 limiter bom.xls

(20 KiB) Downloaded 36 times

Hope this helps.

Regards Andy

[ambroseliao]

Thanks Andy,

That BOM spreadsheet worked like a charm! Thanks so much for posting this and making it easy for us.

[Degull]

For what it is worth, you could order your parts to my place here in Toronto Canada and then I could re-ship them to you. My order from Mouser cost $8 to ship to my place and arrived in about a week. Just pay the shipping from me to you and I would be happy to re-ship it to you.

Here you go, I had issues at first so i made this excel sheet. still need 19 more euro/UK buyers for my £50 group buy

v3 limiter bom.xls

Hope this helps.

Regards Andy

[whereswally606]

Thats a nice offer Degull, i might take you up on it.

tonight i remembered something Mr Fechter said about UK alternatives.

I replied with farnell and RS components.

There is a counter for pickup of parts from in manchester for these parts. so i had a look on the website to match up components.

please would you check this list and check im got some like for like swaps. I know the resistor powers are different ie not 0.125w but 0.4 and 0.6 respectively but i couldnt find exactly similar parts.

v3 limiter components rs components.jpg

(139.07 KiB) Downloaded 3 times

If this file doesnt download properly i can foward the email containing the parts list which it is a screen grab of. Thanks for everybodies time and patience here. especially Mr Fechter's

[Degull]

Be careful when go up in power with the alternative part numbers. The higher wattage resistors will have thicker legs and may not fit into the holes of the board. Try to stick as close to the original spec as you can. If you are going to kit this out, you don't want to have the wrong size parts.

Thats a nice offer Degull, i might take you up on it.

tonight i remembered something Mr Fechter said about UK alternatives.

I replied with farnell and RS components.

There is a counter for pickup of parts from in manchester for these parts. so i had a look on the website to match up components.

please would you check this list and check im got some like for like swaps. I know the resistor powers are different ie not 0.125w but 0.4 and 0.6 respectively but i couldnt find exactly similar parts.

v3 limiter components rs components.jpg

If this file doesnt download properly i can foward the email containing the parts list which it is a screen grab of. Thanks for everybodies time and patience here. especially Mr Fechter's

[megacycle]

Wow, that thing is a monster.

Is there an instruction sheet for it?

One of the two pots on the top of the board might possibly be to adjust the current. That would be pretty handy if so.

http://www.meanwell.com/search/rsp-3000 ... 0-spec.pdf
pumps some good electrons for its size Fech,
Give it a good going over later, for now ptc. precision fence wire
in water bath, the ends were glowing cherry .might need bigger wire

IMGP0052.JPG (246.73 KiB) Viewed 553 times

Intially approx 100A@28.68V, adj to top volts, pulled out of test about 30 secs in, melting the clamp meter and had dropped to 60 odd amps, i think current limiting had started early on, the bi or tri? coloured LED had gone amber.
Better go look see what status LED'S really mean, AMBER STOP NOW, RED TO LATE SMOKED .
Volts down to around 20V at the bottom end of the pot ( stated 20-110%V in specs) is that for external controlled

Need to get this beast to about 29.2V for 8S lifepo4. Where's that service manual .
Zener mod or pot mod have to have a measure around that adj pot.
Hopefully nothing else cuts in with the added 1/2V needed.
I know i can feel my ears burning
why not the 48V version
hmm was considering, but going for 8S, 3 or 4 P,switched for 72 or 96 run, so i'm hoping did the right thing .

[fechter]

Be careful when go up in power with the alternative part numbers. The higher wattage resistors will have thicker legs and may not fit into the holes of the board. Try to stick as close to the original spec as you can. If you are going to kit this out, you don't want to have the wrong size parts.

Yes, those resistors won't fit the holes in the board laying flat, but they may fit OK if you stand them on end and bend the other leg over to reach the hole. This is not as good for vibration, but if the charger sits at home all the time, vibration shouldn't be an issue.

I didn't check the whole list. About the only critical part is the shunt resistor, but even that could be attached with wires if the holes don't line up. Might be ugly, but would work OK.

Edit: I checked the list now and it looks great. As mentioned above, the resistors may need to fit differently, but will function fine.

[fechter]

Give it a good going over later, for now ptc. precision fence wire
in water bath, the ends were glowing cherry .might need bigger wire

We need a picture of that

There's a good chance you can get the extra volt or so out of it just by changing a resistor, but no gurantees. You need to trace out the circuit going from the voltage adjustment pot. Usually one side goes right to ground and the other side goes to a resistor that will set the maximum voltage (until the zener backup kicks in). If you see what the resistance of that one is, then it's easy enough to calculate a value of resistor you can just solder in parallel to the existing one. Probably somewhere on the order of 10K.

Yes, it would be nice to know what the LED is telling you as well as what the other adjustments are for.

I usually carefully mark the original positons of pots before tweaking with them. If tweaking does not make the desired change, return to exact original position. You could smoke it by turning one too far the wrong way.

[whereswally606]

Edit: I checked the list now and it looks great. As mentioned above, the resistors may need to fit differently, but will function fine.

Thanks Fechter, Its still expensive to order from RS cause some of the components have minimum contents orders. May still go with mouser cause im finding that I might have friends at my uni who need to put in a group electronics order. Thanks for checking that list for me, it gives me and other UK builders another option. Will keep everyone posted on my progress on my hp server build.

[megacycle]

Green for go,amber for limiting and red for shutdown.
Temp sensor could have been operating, not sure ,there are 2 on board.

Thats 90+ Amps on the old clamp

The wire was same colour as +V lead at shutdown.

Weekend evenings got some time for fooling around under the lid.
As you said Fech, V adj pot is close to neg rail, about 1 ohm from it at 28V+ end and approx 940 ohms (1k)at 20V end.
Have to check out where the other end of that pot goes to tommorow.
The other 2 pots would be-
(i) current limiting, pdf says is externally adjustable too.
(ii) SVR1= OVP, pdf says 28.8-33.6V . So if i can trim up somewhere OVP pot has good scope.
How to set that hope its not a crowbar scr like others.

[megacycle]

Sorry for thread hogging and going sideway Fetch, but i'm hoping its working out.

IMGP0060.JPG (113.68 KiB) Viewed 489 times

If the 2.32K resistor is in series with the 1K pot and with my little (close to nothing) understanding of the subject,
then if its all linear , the 1k gives approx 8.7V variance, then x 2.32 gives another 8.7x2.32=20.184,all up nearly 49V .
If its true and i need about 30V for charging, ((20.184-1.3)/20.184) x 2.32k = approx 2.17k in circuit.

Parallell resisitor worked out approx 33k.
Just need a nice multiturn to replace that trimpot, digital read outs for the variables and hopefully .