External 5V PSU requirements

  • I am working on a project involving a Raspberry Pi Zero W interacting with my Duet WiFi. I was planning on powering the RPi from the Duet's 5V regulator. Because the RPi need to be powered continuously an external 5V PSU is necessary. Once I realized this, it started thinking of keeping the Duet fed with 5V as well and at a later point adding an SSR to remotely control the main 12V PSU.

    Are there special requirements for the 5V PSU? If I recall correctly the Duet's regulator can provide 2A continuously, so I imagine 2A external would suffice as well. For example would a phone charger with the USB connector snipped off suffice (properly rated ofc)?

  • administrators

    @nxt-1 There are no special requirements as long as you provide enough current for the Duet and the anything connected to it, at a stable 5V. Beware of some phone chargers which only output 4.? volts. For the Duet itself those actually work without an issue as the 5V rail is regulated to 3.3V for the internal logic however some peripherals want 5V. Also the raspi has some low voltage throttling at something like 4.6V

  • @t3p3tony Thanks for the info. I decided to get a quality Mean Well (RS-25-5) with more power than I need.

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