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:
- 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
- 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: