a DC-DC to charge li-ion... GREAT!!

[frodus]

go by the datasheet on the 2.5A I stated above, it'l give you some overage for fudge factor.

As far as the current limit adjust.... I don't think there is one on most AC-DC switchers.... but you can reverse engineer it and tweak it.... but thats not my specialty... limit current by fusing the modules for 3A or so (I know its not real limiting, but keeps things from drawing too much from the supply Fuse the outputs too. Fuse for something OVER 10A

 

[Doctorbass]

go by the datasheet on the 2.5A I stated above, it'l give you some overage for fudge factor.

As far as the current limit adjust.... I don't think there is one on most AC-DC switchers.... but you can reverse engineer it and tweak it.... but thats not my specialty... limit current by fusing the modules for 3A or so (I know its not real limiting, but keeps things from drawing too much from the supply Fuse the outputs too. Fuse for something OVER 10A

I've wrote something about how to force current limit to be lower. I revwersed ingeneered all my BXB150 and now instead of having 30A they have 15.0A. that<s easy to do.. a simple hople in the back plastic case close to the sening pin.. you need to add a resistor between pin 1 and 5 of a PWM current control 8 pins chip. UC2843 if i remember correctly. it will limit the input current so the output current will be too.

 

[efreak]

But In my case i was thinking since the output is 20 amps i would just leave it at the level. for my 4p cells x 10. BTW I would have to charge one pack at a time.

10 module set up.

efreak

 

[frodus]

go by the datasheet on the 2.5A I stated above, it'l give you some overage for fudge factor.

As far as the current limit adjust.... I don't think there is one on most AC-DC switchers.... but you can reverse engineer it and tweak it.... but thats not my specialty... limit current by fusing the modules for 3A or so (I know its not real limiting, but keeps things from drawing too much from the supply Fuse the outputs too. Fuse for something OVER 10A

I've wrote something about how to force current limit to be lower. I revwersed ingeneered all my BXB150 and now instead of having 30A they have 15.0A. that<s easy to do.. a simple hople in the back plastic case close to the sening pin.. you need to add a resistor between pin 1 and 5 of a PWM current control 8 pins chip. UC2843 if i remember correctly. it will limit the input current so the output current will be too.

I realize that, but read my post over again....

I was talking about current limit adjust on the AC power supply, not the DC-DC converter. He asked if he could boost the current limit on the frontend so the 20A supply could deliver 25A for all his modules.... I said maybe, but it would require some reverse engineering.

 

[efreak]

sorry My Bad!

I was referring to the out -put current mine is suppose to be 80% of 20 amp so 18 and a bit so i suppose that is in safe range for charging the 4 p m1s.

now still trying to find a decent power supply.

efreak

 

[efreak]

i bought this meanweel 48v 10 amp power supply p-s-p 500-48

NEW MEANWELL SWITCHING POWER SUPPLY PSP-500-48


This auction is for a new power supply PSP-500-48.

- AC Input: 100/120/220/240 VAC + or - 10%. (47 to 63Hz).
- Output Ripple: 10mV, +0.1% Of Output Voltage Max.
- Stability: 0.1% For 24 Hours After Warm-up.
- Temperature Rating: 0deg. C Full Rated, Derate Linearly To 40% At 70~ C.
- One unit provides 48V/10A
- Supports easy paralelling for up to 2KW of DC power which is ok to run with other supplies




now there are these suppliers in hong kong mentioned above somewhere also on ebay i can seem to get an answer from as to wether their supply is capable of running parallel ??

I am planning on runing three power supplies 10 amp each for a total of 30 amps to supply the 10 modules 2.5 amps each i might have to add more dummy modules if i have to for fans say. the question is wether this mean well ps work with the hk ones ( 2 more) or do the hk ones work with one another . man i got to get a move on.


while here any better place for cilicon covered 14 gauge for batt pack the place doc said somehwere man 65 shipping thanks though with due respect

can i just use the stuff from powerex same place you get powerpoles?

efreak

 

[commanda]

If you divide the modules between your 3 Meanwell power supplies; 3 on ps1 & ps2 = 7.5 amps each and 4 on ps3 = 10 amps.

Forget about putting the Meanwell's in parallel.

Amanda.

 

[Doctorbass]

i bought this meanweel 48v 10 amp power supply p-s-p 500-48

NEW MEANWELL SWITCHING POWER SUPPLY PSP-500-48


This auction is for a new power supply PSP-500-48.

- AC Input: 100/120/220/240 VAC + or - 10%. (47 to 63Hz).
- Output Ripple: 10mV, +0.1% Of Output Voltage Max.
- Stability: 0.1% For 24 Hours After Warm-up.
- Temperature Rating: 0deg. C Full Rated, Derate Linearly To 40% At 70~ C.
- One unit provides 48V/10A
- Supports easy paralelling for up to 2KW of DC power which is ok to run with other supplies




now there are these suppliers in hong kong mentioned above somewhere also on ebay i can seem to get an answer from as to wether their supply is capable of running parallel ??

I am planning on runing three power supplies 10 amp each for a total of 30 amps to supply the 10 modules 2.5 amps each i might have to add more dummy modules if i have to for fans say. the question is wether this mean well ps work with the hk ones ( 2 more) or do the hk ones work with one another . man i got to get a move on.


while here any better place for cilicon covered 14 gauge for batt pack the place doc said somehwere man 65 shipping thanks though with due respect

can i just use the stuff from powerex same place you get powerpoles?

efreak

Use a diode in serie with the (+) of each mean well power supply and then parallel them.. you can of course paralle them! but dont forget to use a diode in serie with twice the A rating than the current each will have.. so 20A or 30A shottky would be great.

Ebay have them for cheap (shottky diode) I bought 13x 40A of them for 20$

Also i would suggest to put one of these a diode in parallel to each DC-DC converter output (i talk about the 5V output.. not the 48V input..) conect them in not polarised sens.. you dont need a short circuit.. you need to protect the output! :wink:

That will protect them against reversal current if connection trouble would occur. I would say.. YOU MUST HAVE THEM !

 

[frodus]

why even parallel them? just more parts cost and more wiring. Just split X modules between Y number of power supplies and you're done.

 

[efreak]

yes thanks a lot folks

me duh!

sure frodus that's a great idea i gues i was affraid or no sure of efects if any of the equal amounts of currents to each modules but i think that is not a big concern with that set up i got a good deal on the meanwell and need to purchase 2 of the Hong Kong ps for the rest. and diodes at convertr out put thanks for that i ll have to put that for sure a 30 amp might be ok for that or maybe 40 amp.

efreak

 

[frodus]

here are some 3.3V output DC converters 30A (also has 12V outputs).... 28 of them, for 15 bucks

33-75V input
3.3V/30A out
and 2 12V/4.2A out
with Trim


one auction for 28:
http://cgi.ebay.com/28-CD-TECHNOLOGIES-VKP100MT312-DC-DC-CONVERTERS_W0QQitemZ140239305847QQihZ004QQcategoryZ4660QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

and another for 21:
http://cgi.ebay.com/21-CD-TECHNOLOGIES-INC-DC-DC-CONVERTERS_W0QQitemZ140239185466QQihZ004QQcategoryZ4660QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Here's an interesting Idea.... say you build 20 cells worth, and get ~64V (3.2V cells), you could put the pack voltage, directly to the input of the converters, and equalize a low cell from the pack voltage (only one of the converters would be enabled at a time).... but its an option to keep a low cell from overdischarging.

 

[efreak]

thanks again
getting to know dc - dc convereters has been wonderful


now i am contemplating like Doc said in another post summarized dc -dc tutorial i think

to just attach the modules to the Power supply body for heat dissipation < if that is going to work it will be one less step

having get extruded aluminum or older pc heat sink

 

[Doctorbass]

here are some 3.3V output DC converters 30A (also has 12V outputs).... 28 of them, for 15 bucks

33-75V input
3.3V/30A out
and 2 12V/4.2A out
with Trim


one auction for 28:
http://cgi.ebay.com/28-CD-TECHNOLOGIES-VKP100MT312-DC-DC-CONVERTERS_W0QQitemZ140239305847QQihZ004QQcategoryZ4660QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

and another for 21:
http://cgi.ebay.com/21-CD-TECHNOLOGIES-INC-DC-DC-CONVERTERS_W0QQitemZ140239185466QQihZ004QQcategoryZ4660QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Here's an interesting Idea.... say you build 20 cells worth, and get ~64V (3.2V cells), you could put the pack voltage, directly to the input of the converters, and equalize a low cell from the pack voltage (only one of the converters would be enabled at a time).... but its an option to keep a low cell from overdischarging.

they are perfect for A123!! +10% would give 3.65V !! amazing!

but are they isolated in-out?

 

[frodus]

Doc...

http://www.datasheetcatalog.org/datasheet/candd/VKP100XT.pdf

they're Isolated... most switching DC converters are... only a few cheapo "regulator" converters aren't.

They're perfect... and CHEAP!

 

[Doctorbass]

Doc...

http://www.datasheetcatalog.org/datasheet/candd/VKP100XT.pdf

they're Isolated... most switching DC converters are... only a few cheapo "regulator" converters aren't.

They're perfect... and CHEAP!

that's great!

If you get them, would you sale me one or two? i need some for the 12V output.

 

[frodus]

I'm not buying them... I have the modules I need.
Just bought a 150W 48-12V converter for my auxiliary. Takes up to 60 in. There's a couple more.... they were ~30.

I just wanted to give you guys a heads up on deals I see... thats all.

 

[efreak]

I used the formula on page 11 of the data sheet for my tyco modules


http://www.torontosurplus.com/tes/DataSpec/Tyco_QHW100F.pdf
and i need to Increase ( second formula )probably 10% the out put voltage to 3.63 i guess so with my rudemetary calculations i arrived at 25.6 k ohm
i know Doc had advise me on splitting this resistance between resistor and pot
90 % resistor and 10 % potentiometer

so i just like to ask help on this number thanks in advance so i can order the correct parts thanks

 

[manfred59]

another 20A converter here http://cgi.ebay.com/Power-One-QES06...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247
I think they also could be trimmed to 3,65V.
What multipin connectors would be the best?

 

[efreak]

I used the formula on page 11 of the data sheet for my tyco modules


http://www.torontosurplus.com/tes/DataSpec/Tyco_QHW100F.pdf
and i need to Increase ( second formula )probably 10% the out put voltage to 3.63 i guess so with my rudemetary calculations i arrived at 25.6 k ohm
i know Doc had advise me on splitting this resistance between resistor and pot
90 % resistor and 10 % potentiometer

so i just like to ask help on this number thanks in advance so i can order the correct parts thanks

so 2.5k ohm pots?

 

[efreak]

another 20A converter here http://cgi.ebay.com/Power-One-QES06...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247
I think they also could be trimmed to 3,65V.
What multipin connectors would be the best?

and 20 amp is good

simple one wire connector i think would work

 

[efreak]

I used the formula on page 11 of the data sheet for my tyco modules


http://www.torontosurplus.com/tes/DataSpec/Tyco_QHW100F.pdf
and i need to Increase ( second formula )probably 10% the out put voltage to 3.63 i guess so with my rudemetary calculations i arrived at 25.6 k ohm
i know Doc had advise me on splitting this resistance between resistor and pot
90 % resistor and 10 % potentiometer

so i just like to ask help on this number thanks in advance so i can order the correct parts thanks

so 2.5k ohm pots?

Yes?

 

[fefifofob]

I used the formula on page 11 of the data sheet for my tyco modules


http://www.torontosurplus.com/tes/DataSpec/Tyco_QHW100F.pdf
and i need to Increase ( second formula )probably 10% the out put voltage to 3.63 i guess so with my rudemetary calculations i arrived at 25.6 k ohm
i know Doc had advise me on splitting this resistance between resistor and pot
90 % resistor and 10 % potentiometer

so i just like to ask help on this number thanks in advance so i can order the correct parts thanks

I looked at http://www.torontosurplus.com/tes/DataSpec/Tyco_QHW100F.pdf

and I can see why you are not sure. That equation leaves a lot of room for interpretation.

Here's another data sheet with a trim-up equation that looks like it's the same as yours. However, they have a graph of resistances vs voltage on page 6. From the graph, it looks like you need about 100K. You might try validating the equation against the graph.

http://www.dodeca.ru/files/pkb4610_r1d_1102.pdf

PS: I think I might make the pot able to center on the range I need. For example, if this needs 100K, I might use 90K fixed and 20K variable to be able to go from 90K to 110K.

 

[efreak]

First of all welcome to the forum fefifofob ( round of applause....)

Second thanks you for your valuable input. indeed a great sugession as well as Doc old split ratio approach for better control.

so 100 Kohm and 20 k potentiometers with 90 k ohm resistors?



the link also has some very interesting intriuges about the use and encouraging the use of capacitators when dealing with dynamic loads

( something they working on ev s for sure )

thanks again

 

[fefifofob]

First of all welcome to the forum fefifofob ( round of applause....)

Second thanks you for your valuable input. indeed a great sugession as well as Doc old split ratio approach for better control.

so 100 Kohm and 20 k potentiometers with 90 k ohm resistors?

the link also has some very interesting intriuges about the use and encouraging the use of capacitators when dealing with dynamic loads

( something they working on ev s for sure )

thanks again

Thank you.

I didn't spend the time I would have spent verifying that both equations were the same and that the graph matched the equation as I would have if I was spending my hard earned money. At first glance, I could see where the equations were rearranged at bit. I thought you could use it to verify your calculations because what values get plugged into each one is pretty unclear. With the graph though, you could at least have some way of seeing how varying the numbers worked. For example, I wasn't sure if a 10% gain was expressed as a delta-V of 10 or 110 or 1.1 (110%) or 0.1 (10%).

Your welcome, but I didn't do all the work. I don't think I would depend entirely on specs from a different part, even though the adjustment seems to be somewhat of a standard.

 

[efreak]

thanks again those are similiarly my concerns since youcould get get different values depending on what you have to use but the part on that link about the industery standard reassuring as well the graph is very helpful i'd have to do some testing of course but it wil give me some starting point

"
These converters
trim according to the industry standard method."

Doc was mentioning this in another post but the numbers he used were i think either hypothatical or for trim down perhaps but as soon as get my power supply i ll do stests