Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Confused about power supply. 24v PS using buck converters down to 5v.

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    Oct 2015
    Posts
    10
    Post Thanks / Like

    Default Confused about power supply. 24v PS using buck converters down to 5v.

    So lets say I'm going to have 450 5v pixel nodes ran off a power supply. 3 amps per string totaling 27amps at 5v. How do I figure out what amperage/wattage 24v power supply I would use? I tried using ohm's law but I just can't seem to get it.

  2. #2
    Join Date
    Dec 2011
    Posts
    5,475
    Post Thanks / Like

    Default Re: Confused about power supply. 24v PS using buck converters down to 5v.

    Save yourself $$$ both on hardware and hydro

    Use 5v 60 power supply

  3. #3
    Join Date
    Oct 2015
    Posts
    10
    Post Thanks / Like

    Default Re: Confused about power supply. 24v PS using buck converters down to 5v.

    Quote Originally Posted by angus40 View Post
    Save yourself $$$ both on hardware and hydro

    Use 5v 60 power supply
    I was originally going to do that but getting 5v's to the far strips would need some serious wire gauge. Or am I doing something wrong?

  4. #4
    Join Date
    Oct 2014
    Location
    Sauk City, WI USA
    Posts
    868
    Post Thanks / Like

    Default Re: Confused about power supply. 24v PS using buck converters down to 5v.

    Assuming perfect conversion,
    5v @ 27A = 135 w
    24v @ 135w = 5.625A
    Throwing a bunch of bucks into the mix and you will likely use a bit more.
    Here is where I found the calculator.
    https://videos.cctvcamerapros.com/vo...tts-conversion

  5. #5
    Join Date
    Dec 2012
    Location
    Hudson MA
    Posts
    2,762
    Post Thanks / Like

    Default Re: Confused about power supply. 24v PS using buck converters down to 5v.

    Power / voltage = current.
    Buck converters are about 80% efficient.
    Yes you can use smaller guage wire with less loss using a higher voltage. My show has over 60 buck converters in it.


    2018 - Moving and going to visit my Daughter in New Zealand. Most likely I will be dark or nearly dark, Some static stuff that is simple to put up.

  6. Likes plasmadrive liked this post
  7. #6
    Join Date
    Jan 2017
    Posts
    113
    Post Thanks / Like

    Default Re: Confused about power supply. 24v PS using buck converters down to 5v.

    Quote Originally Posted by MartinMueller2003 View Post
    My show has over 60 buck converters in it.
    Can you give any links/info on the buck converters you're using? I've tried 3 different types and none of them work so far. I order them in quantities of 5 so I have 15 defective buck converters. They don't drop the voltage at all.

  8. #7
    Join Date
    Jan 2015
    Location
    Folsom, CA, USA
    Posts
    1,496
    Post Thanks / Like

    Default Re: Confused about power supply. 24v PS using buck converters down to 5v.

    If you have 3 different lots of defective Bucks, you likely have an installation issue.

    I like using smaller area transformers...usually weatherproof. 120V go a long, plus the transformer usually fixes voltage drop. I have no oversized wire in my layout.....but I have a lot of 120V, and much more efficient.
    Last edited by mrGrumpy; 06-11-2018 at 11:07 AM.
    In Lights Therapy

  9. #8
    Join Date
    Jan 2017
    Posts
    113
    Post Thanks / Like

    Default Re: Confused about power supply. 24v PS using buck converters down to 5v.

    Quote Originally Posted by mrGrumpy View Post
    you likely have an installation issue.
    I wish that was the case. These don't work on the bench, right out of shipping. The ones I have are based on an LM2596 and usually fail in a fully closed state. The trim pot was the culprit in one batch but the other 2 batches seem to have bad regulators. Given the price and quality I suspect they have some counterfeit parts. I have a dozen TI LM2596's on order but still don't trust the circuit .

  10. #9
    Join Date
    Dec 2012
    Location
    Hudson MA
    Posts
    2,762
    Post Thanks / Like

    Default Re: Confused about power supply. 24v PS using buck converters down to 5v.

    Quote Originally Posted by dcamron View Post
    Can you give any links/info on the buck converters you're using? I've tried 3 different types and none of them work so far. I order them in quantities of 5 so I have 15 defective buck converters. They don't drop the voltage at all.
    I use these. WARNING. They come set to MAX VOLTAGE. You need to manually adjust them to 5V. I set them to 5.45v-5.50v using my external voltmeter. I run them a bit high but my lights seem to like it. I also glue a heatsink on the top of the IC and on the board under the IC. Without the heatsinks they cannot go above 2A. With heatsinkls they run at 3A very nicely.

    https://www.ebay.com/itm/DC-DC-3A-ad...8AAOSwk-1aSHN5


    2018 - Moving and going to visit my Daughter in New Zealand. Most likely I will be dark or nearly dark, Some static stuff that is simple to put up.

  11. #10
    Join Date
    Jan 2013
    Location
    Tucson, AZ
    Posts
    982
    Post Thanks / Like

    Default Re: Confused about power supply. 24v PS using buck converters down to 5v.

    I drive 12 outputs up to 60 ft away using that technique. The attached photo shows the parts used in case it helps.
    Attached Images Attached Images
    Didn't pay for a sig

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •