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I plan to power 5 SBC boards through a single power-supply. Each board consumes 5V at 3A max. The power source is ordinary 230VAC (EU). I am uncertain how to connect everything in a sane way.

I want to operate this 24/7 under normal indoor conditions. Eventually everything should be contained in a box. But until then it has to lay open. The solution has to be quiet and should not produce much heat. The 5 boards should consume power roughly in the same dimension. If one malfunctions or gets plugged off, it should not impact the others.

Main questions

  1. Do I need additional elements between the power-supply and the boards? e.g. limit the max current to 3A.

  2. How to split the power into 5 lanes? Should I build a Stripboard or can it be done as a heat-shrink-tubed bundle of wires?

Side questions

  1. There are a lot of power-supplies similiar to the one I picked. What specs should I look out for except the total Watts?

  2. Does it make sense to use a bigger power-supply in the 100 Watt range to get higher efficiency or lower heat? The pricing seems close.

Thanks a lot.

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  • \$\begingroup\$ You can just wire them in parallel, no special devices needed. It's up to you which type of wiring (plain wires, stripboard, ...) works best for your project. \$\endgroup\$
    – user253751
    Apr 22, 2018 at 23:30
  • \$\begingroup\$ Thanks @immibis. I hope for more details on how physically connect the 5 outlets to the power supply. I have no good idea at the moment. \$\endgroup\$
    – Roman
    Apr 23, 2018 at 17:16

1 Answer 1

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To prevent glitches on hot insertion some decoupling is necessary.

Consider the step load of 1A plus the ESR of the onboard caps vs the source ESR. Step load regulation is this ratio of impedances when you want <5% step load error.

This is typically done so that the response time of the step load is slower than the sources reaction time which may be in the 10~1000us time depending on quality and excess power of the source . This can be accomplish with chokes, caps and/or holding current ICL’s and / or inrush current limiting polyresistors with NTC at 120’C and draw ~0.5W

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  • \$\begingroup\$ What happened to the rocket since? :) How about CC/CV circuits as buffers between the PS and the loads? \$\endgroup\$
    – user76844
    May 9, 2020 at 17:09
  • \$\begingroup\$ @GregoryKornblum Did U You mean rocket Science? Hot insertion demands that the static load on insertion be much higher impedance than the bus to prevent step dropouts. \$\endgroup\$
    – Tony Stewart EE75
    May 9, 2020 at 17:35
  • \$\begingroup\$ Science it is . \$\endgroup\$
    – user76844
    May 9, 2020 at 18:10

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