Modern PSU with ATX voltages? - Page 1
Forum section: electronics / general

author: DoublesAdvocate
author_rank: Newbie
timestamp: May 12, 2025, 04:49:57 am
content: Not sure if this is the correct sub-forum to ask this question but I'm looking for a small power supply to replace the PSU in an old PlayStation 3 which takes an input of 100-240V from the wall and outputs 3.3V, 5V, and 12V simultaneously.The only complication being that the 12V supply has to be capable of a little over 30A of current meaning all the solutions I've been able to find online are usually far below the demands of the console.Normally I would just buy a traditional off the shelf ATX PSU for something like this but the problem is they're all far too large to fit inside the console, even smaller standards like TFX or SFX wouldn't fit.Just as an aside I put "modern" in the title because I'm hoping for one with better efficiency since the PSUs in the PS3 are readily available but they all top out around 80% efficient, with the worst offenders reaching around 65% efficient.If anyone has any suggestions for closed source options I'm willing to hear them as well.

author: Poroit
author_rank: Frequent Contributor
timestamp: May 13, 2025, 07:20:35 am
content: G'day DoublesAdvocate,Is there space for two power supplies? eg 3.3V +5V and a separate 12V

author: Kean
author_rank: Unknown
timestamp: May 13, 2025, 09:55:21 am
content: Which actual model PS3 is it? Most of the OEM PSUs do not appear to have a 3.3V rail.https://www.psdevwiki.com/ps3/Power_SupplyThis web page seems to indicate you can use one of the more efficient PSUs in older models, but you'd need to cross check your actual unit.I've never worked on one of these, but it seems likely that only a specifically designed PSU is going to fit in the available space.

author: DoublesAdvocate
author_rank: Newbie
timestamp: May 14, 2025, 12:23:44 am
content: Quote from: Poroit on May 13, 2025, 07:20:35 amPossibly? Although if I went with 2 I'd then need to split the input coming from the wall. They're all a bit oddly shaped but I think the height should be the only limiting factor. Sony really worked hard to make them sleek so they slope down to that 3/4cm height.15x15x3cm (base)8x27x4cm (slim)8x25x3cm (super slim)Quote from: Kean on May 13, 2025, 09:55:21 amYou're totally right, I don't know where I got the 3.3V from I think I probably had some of the board voltages on the brain.It's not so much the efficiency as the heat and space I'm concerned about. The idea is to free up some space inside for a small fan or a slightly larger heatsink while reducing the heat given off by the PSU.I should also add that although the output spec is ~32A I don't believe the console ever actually reaches anywhere near that metric. The highest power draw I've ever been able to measure was under 250W meaning it likely never pulls more than 20A and the additional headroom was to hit the efficiency target.

author: DoublesAdvocate
author_rank: Newbie
timestamp: May 16, 2025, 11:11:16 pm
content: I found this randomly crawling around the web.It doesn't include the resistor values but it does appear to be an otherwise accurate schematic for the APS-226 model of power supply.https://www.elektroda.com/rtvforum/topic2063753.html