Author Topic: Want tips on DC-DC psu's in dumpster  (Read 880 times)

0 Members and 1 Guest are viewing this topic.

Offline stenorTopic starter

  • Contributor
  • Posts: 20
Want tips on DC-DC psu's in dumpster
« on: September 25, 2020, 08:15:10 am »
Want to know if there are some good, common targets to look for in the e-waste.

Looking for:
  • High current, 10A++
  • DC input ~36-100v, output variable or 12/24/48v
  • Simple/sturdy construction, preferably
  • Good efficiency

I read that some atx psu's can run directly on dc, although I wonder about efficiency. I'd be feeding it maximum ~70v dc.
« Last Edit: September 25, 2020, 08:17:43 am by stenor »
 

Offline Kjelt

  • Super Contributor
  • ***
  • Posts: 6586
  • Country: nl
Re: Want tips on DC-DC psu's in dumpster
« Reply #1 on: September 25, 2020, 08:19:38 am »
IIANM most modern PC PSUs run on a 12V rail, so if you open them up you can find 12-5VDC-DC converters and 12V-3.3V DC-DC converters or 5V-3.3VDC-DC converters.
However they are 85-92%efficient on high current loads only, if you only draw an amp or less they might end up in the low 80s % eff.
 

Offline daqq

  • Super Contributor
  • ***
  • Posts: 2321
  • Country: sk
    • My site
Re: Want tips on DC-DC psu's in dumpster
« Reply #2 on: September 25, 2020, 01:38:05 pm »
In the better class of e-waste (high end servers, special tech), look for anything labelled VICOR. They make some delightful power modules which pack amazing features into deceptively small sizes.

Variable output however is rare - best you can hope for is some center voltage around which you can slightly adjust by +/- 10%. Or maybe abusing sense lines? But not by much.
Believe it or not, pointy haired people do exist!
+++Divide By Cucumber Error. Please Reinstall Universe And Reboot +++
 

Offline Cubdriver

  • Supporter
  • ****
  • Posts: 4201
  • Country: us
  • Nixie addict
    • Photos of electronic gear
Re: Want tips on DC-DC psu's in dumpster
« Reply #3 on: September 27, 2020, 08:37:01 am »
In the better class of e-waste (high end servers, special tech), look for anything labelled VICOR. They make some delightful power modules which pack amazing features into deceptively small sizes.

Variable output however is rare - best you can hope for is some center voltage around which you can slightly adjust by +/- 10%. Or maybe abusing sense lines? But not by much.

The Victor Vicor Maxi/Mini/Micro series of D.C.-D.C. bricks can be trimmed from 10% (lower if loaded sufficiently) up to max using the 'SC' pin - we used them to drive and regulate variable output RF power supplies at my previous job by controlling the applied voltage.  Their packaging efficiency seems to have improved since I last used them in 2007 - IIRC back then the full brick was good for 200W and they now do 400 and 500W units in that package, but it's been a loooong time so I may be misremembering the exact detail in the physical size vs output.  I know we used two different generations of them over the years I worked there.

They proved to be very user friendly implementation-wise, and were quite reliable, too.

-Pat

<Edit - goddamned autocorrect!!!>
« Last Edit: September 27, 2020, 11:54:00 am by Cubdriver »
If it jams, force it.  If it breaks, you needed a new one anyway...
 

Offline daqq

  • Super Contributor
  • ***
  • Posts: 2321
  • Country: sk
    • My site
Re: Want tips on DC-DC psu's in dumpster
« Reply #4 on: September 27, 2020, 10:09:56 am »
In the better class of e-waste (high end servers, special tech), look for anything labelled VICOR. They make some delightful power modules which pack amazing features into deceptively small sizes.

Variable output however is rare - best you can hope for is some center voltage around which you can slightly adjust by +/- 10%. Or maybe abusing sense lines? But not by much.

The Victor Maxi/Mini/Micro series of D.C.-D.C. bricks can be trimmed from 10% (lower if loaded sufficiently) up to max using the 'SC' pin - we used them to drive and regulate variable output RF power supplies at my previous job by controlling the applied voltage.  Their packaging efficiency seems to have improved since I last used them in 2007 - IIRC back then the full brick was good for 200W and they now do 400 and 500W units in that package, but it's been a loooong time so I may be misremembering the exact detail in the physical size vs output.  I know we used two different generations of them over the years I worked there.

They proved to be very user friendly implementation-wise, and were quite reliable, too.

-Pat
Oh yes, they are very good devices, I used them for weird stuff as well. The modern ones have an insane power per volume ratio, see: http://www.vicorpower.com/products?productType=cfg&productKey=DCM3717S60E14G5TN0
As to their control interface, the ones I've worked with were pretty much 'just add some caps and you're good'.
Believe it or not, pointy haired people do exist!
+++Divide By Cucumber Error. Please Reinstall Universe And Reboot +++
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf