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I'm a newby in the field of Electrical Engineering (only basic knowledge from school). Nevertheless, I need to power up to 10 Raspberry Pis (5V, 2A) with Dupont Connectors and AWG24 cables over GPIO header. I have a power supply unit giving me max 30A at 5V.

My question is, can I just etch e.g. two lanes on a PCB and solder a Dupont header (10 by 2) with 10 output pairs (each for one device) to them and powering those lanes at the end with one input pair coming from the psu (with stronger wire gauges, maybe AWG18)? Of course I would apply solder masking, to prevent short circuits and oxidation.

This seems a bit naive, so I'm asking your opinion. Maybe you are aware of other neat solutions?

m0r0n
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  • Does your project require a PCB here? Why not use 2 bus bars instead, 1 for 5V 1 for GND? They're cheap and won't require any designing. Like these: https://www.dropbox.com/s%2Fve5x1gx2ogmq12h%2F2019-08-01%252009-34-01.png%3Fdl%3D0 – Jim Aug 01 '19 at 13:34
  • If you do a two-lane PCB, add some reservoir capacitors to this PCB as well (of considerable capacity). – glen_geek Aug 01 '19 at 13:56
  • @Jim thanks for your comment. Yes, I've seen those already and it doesn't require a PCB. I'm just wondering if the resistance of those bus bars has a negative impact on the voltage? – m0r0n Aug 01 '19 at 13:59
  • @glen_geek thanks also for your comment. Speaking about capacitors, what would I look at here? Do you have any good resource for me to read about this? What would you consider a "considerable capacity" in this case and for what reason? – m0r0n Aug 01 '19 at 14:01
  • Why only 10x2? GPIO is 20x2. Connect **all 8 GND** and **both +5v**… that would make your PCB 10-lane. If you expect one RPI to communicate via GPIO to another, they all must have a solid, unvarying ground reference. Most RPI versions have many microfarads on-board capacitance on their +5V inputs. If you include capacitors on your DCsupply distribution board, they should be even larger, like 470uf or 1000uf. – glen_geek Aug 01 '19 at 15:02
  • @glen_geek I think I didn't got your last comment. The RPis should not communicate with each other via GPIO, they should just get power supply via GPIO, that's 2 pins, one GND and one +5V input, right? Is it really necessary to connect all 8 GND and both +5V? Reason? As I see it from multiple sources, it's fine to use only one of both e.g. here https://pinout.xyz/pinout/pin4_5v_power# – m0r0n Aug 01 '19 at 16:02
  • Your ten-RPi application has *nothing else interconnected*? They're completely independent, other than a common +5V power feed? If that is so, then ensuring a solid ground and supply connection can be relaxed. But I can't imagine doing anything useful with a RPi connected to nothing else. – glen_geek Aug 01 '19 at 16:50
  • @glen_geek they are connected to a network switch via ethernet port, if that's what you are asking for? Do you mean with "can be relaxed", I can go with the aforementioned suggestion from Jim? Or would you still use capacitors? – m0r0n Aug 01 '19 at 17:22
  • Yes, ethernet is probably the only peripheral that doesn't have a DC-connected ground ... that's good. A keyboard & mouse & camera would be OK too provided they float (no ground connection). – glen_geek Aug 01 '19 at 18:03

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