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DC converter needed

01/05/2022 2:34 AM

Hi folks,

I have a 72V battery, and need to convert it to 24V-10A to be used for a powered mechanical system. The DC converter should be selected to be as small, light-weight, and compact as possible, to satisfy given conditions.

Could you please recommend a good solution for the converter (model#)?

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#1

Re: dc converter needed

01/05/2022 2:57 AM

These people certainly can.

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#2

Re: DC converter needed

01/05/2022 8:13 AM

150*35*50mm / 5.9*1.4*2in

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#3

Re: DC converter needed

01/05/2022 11:02 PM

Something like this is about the size of a Hershey bar and provides up to 320 watts.

3.38 x 1.4 x 0.37in / 85.93 x 35.54 x 9.4mm

https://www.vicorpower.com/products?productType=cfg&productKey=DCM3414V75H26C2C01

In addition to heatsinking, you probably need to hang off a few parts like de-coupling capacitors and maybe some filtering depending on your application, but these are tough to beat. Do read the applications guidelines especially if there is a long run of wire between your battery and the converter.

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#4

Re: DC converter needed

01/06/2022 6:41 AM

For top quality you can't beat Vicor as Brave Sir Robin suggested.

If commercial or DIY quality are your target zone then look at Mean Well Corporation power supplies from Mouser, Digikey and various other vendors.

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#5

Re: DC converter needed

01/06/2022 10:45 AM

I haven't tried on that voltage, but, could a simple rectifier do the job??

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#6

Re: DC converter needed

01/07/2022 12:05 AM

Search internet for buck converters. I have used a few to provide 24V or 12V from 48V or 72V UPS backup batteries to power small loads up to 20Amps. The best ones use a SMPS to chop the incoming DC, transform it, rectify it and provide an adjustable output which is over current and overvoltage protected.

Search this on ebay "dc dc converter 72v to 24v"

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#7

Re: DC converter needed

01/07/2022 10:23 AM

A 72 Volt battery is almost certainly six 12 Volt batteries, so, why not just rewire them to three parallel by 2 serial.

If you only have a 72 Volt charger: then you could include a few switches to change between the two configurations.

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#8

Re: DC converter needed

01/13/2022 10:36 PM

Hi nzur,

one important feature to be specified when selecting DC-DC converters is galvanic isolation, ie: does the output voltage have to be galvanically isolated from the input voltage? If "yes", then you will need a DC supply that offers galvanic isolation between input and output, and the next question would be: what is the isolated voltage required between output and input? Both of these parameters have a significant impact on what solutions should be applied.

However, please note that galvanically isolated supplies are generally physically larger, have more power loss, and are more expensive than non-isolated supplies. This is because the electrical power is coupled from the input to the output via a transformer (usually one with a high-frequency ferrite core) whereas non-isolated types do not need this transformer.

If there is any doubt as to whether or not isolation is required, then it is best to select a supply with galvanic isolation as standard - at least during the development/prototyping stage of the product you are working on. If the project is a one-off, then it has been my experience that the extra cost of the isolated DC supply is well worth it just to eliminate ground loops as a source of potential headaches and the time wasted to diagnose such issues.

The great advantage of isolated supplies is that they can speed up time to market since they solve a multitude of problems particularly during the prototyping stage, such as: breaking up ground loops, and generally have lower EMI than non-isolated supplies. When re-engineering a prototype ready for production ie: reducing costs, rationalising components & supply chains, etc) then each electrical power supply can be reconsidered based on its requirements, and galvanic isolation is just one parameter to consider during that process.

Hope this helps.

Cheers.

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#9
In reply to #8

Re: DC converter needed

01/14/2022 12:43 AM
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