OK, so these are my first uninformed baby-steps towards realizing my overly ambitious world-dominating bench/lab power supply, but i am old enough to handle people laughing at me or calling me an idiot, so this will not be a tested and verified recipe for how to build a power supply, but rather document my progress or failures through my learning process and perhaps someone can at least learn how not to do (I will make sure to add a section in my last will and testament requesting someone to post a warning here if this ends up causing my early demise).


  • Safety first - while building and when using.
  • ATX PSUs are made for ATX cases, use it!
  • Minimize reinvention, if there is a part that is ready to buy, buy it and use it!
  • Push the boundaries of my knowledge to expand them, don’t step over them!!!
  • Avoid unnecessary investment where possible
  • Use low-cost sources (Aliexpress/Banggood/ebay)
  • If possible, re-use my beautiful analog Conar Instruments gauge (mostly for style points).

Desired Features/Wish list:

  • 220v/50Hz input
  • Big, bright, obvious power indicator LED - Thanks to Martin
  • Touch screen display
  • Six output channels + USB power outputs:
    • 3.3v
    • 5v
    • 12v
    • -12v(?)
    • 0-30V/5A Variable CC/CV
    • USB 5v power-only ports for convenience (possibly with V/A display)
  • Individual breaker/switch for each output
  • Rotary encoders for controlling variable output - thanks Martin for the suggestion!
  • Current limiting
  • WiFi Connectivity
  • Displays and logs current (+Min/Max)
  • Displays and logs voltage (+Min/Max)
  • Color coded outlet posts /displays
  • Per-outlet V/A display
  • Temperature sensors
  • Variable Fan Cooling controlled by temp sensors and MCU
  • Use ATX power input with fuse and switch (if within specs)
  • 4-Channel 2.5V/7.5V/5V/10V Voltage Reference
  • Real time clock (on Nextion display) and online NTP sync

Nice to have:

  • Plug-n-play modular (drive bay enclosures?) - possibly in the future if i find a cheap case with 4-6 large drive bays.
  • Tentative: Timer/shutoff per-channel (for long running and remotely monitored labs)?
  • Display/Log Watts, Watt Hour
  • Measuring μA

Open points:

  • Selectable and bypassable automatic reset/polyuses for each channel? - Ref. Dangerous Prototypes ATX breakout board.
  • Use OpenDPS and a DPS5005 for the variable power?

Considered and removed/rejected:

  • Integrated residual-current circuit breaker(?) - adds no protection here - advised against by Martin and Chris.
  • Timer shutoff for whole power supply - inconvenience, may interrupt work - advised against by Martin and Chris.

References and inspiration:

Peter Oakes: