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Y splitter for power pins?

Mon Jul 23, 2018 2:56 pm

Hi all,

I have a bit of a problem. I have a few breakout boards and not enough power and ground pins. I don't need a lot of draw (very low amp boards) but I do need a few more 5v or 3.3v pins and better-placed ground pins. This isn't for passing data but just for power and signal voltages. Also, it would be really nice to have a few more grounds. Is this fairly common to do or is this just a terrible idea on its face?


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Re: Y splitter for power pins?

Mon Jul 23, 2018 3:11 pm

It's a common problem and Y-splitters are one solution. If into home electronics you can build them yourself. You can make long chains of connectors like fairy lights.

Another option is to solder rows of header pins on a lump of stripboard and have a 5V, 3V3 and 0V distribution board. Handy for pushing female dupont jumpers on to. But be careful not to short pins.
Last edited by hippy on Mon Jul 23, 2018 3:13 pm, edited 1 time in total.

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Re: Y splitter for power pins?

Mon Jul 23, 2018 3:12 pm

Everyone will end up splitting power pins.

Consider a breadboard
The lines of holes that appear at the top and bottom (with the red/blue lines) of a breadboard are used to share a single power supply with many different parts of the circuit and given that breadboards commonly have 4 supply 'rails' you can have 4 different voltages/grounds (i.e. 5v, 3.3v, Ground).
The same principles can be adopted on stripboard or on a PCB where a single 5v supply PCB track will be routed round the board to supply everything that needs 5v.
There are also Perma-proto boards made by Adafruit which can be used for a more permanent version of a breadboard prototype. A Pi specific version also exists

Rather than splitting power pins, you can always "daisy-chain" from one device using 5v to another.
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Re: Y splitter for power pins?

Mon Jul 23, 2018 3:29 pm

This might sound like a "shooting flies with a bazooka" solution, but in the long run, I find it worthwhile.

I use a half size breadboard with external power supply for larger projects. It's set up like a power strip and only supplies power, no circuit components are mounted to it. One side is 5vdc and the other 3.3vdc, with ground. The bench supply connects to the "red/blue" power rails which act as a "bus". I then jumper from the "bus" to the "matrix", the section with the letters and numbers, when I need to route power to separate devices. The "gutter" in the center separates the two and they are labeled as well. It's then a simple matter to jumper from the "power breadboard" to a standard breadboard with my circuit prototype(s) on it. By using the "matrix" I can keep track, using the letters and numbers, of where power is being routed to which device. Sounds a bit more complicated than it is in actual use and wonderful for complex projects with lots of circuits and the wiring needed to power them all.

Here's a simple way to turn a PC power supply into a bench power supply for RPi and Arduino projects: ... y-adapter/ You'll note the PC power supply already has the needed 5vdc/3.3vdc positive and grounds. 12vdc is a bonus. ;)

This is working very well for a project where I'm using a RPi3B and 4 Arduino Uno devices along with sensor and motor boards and I have to supply both 5vdc and 3.3vdc to the circuits. 12vdc comes right off the bench supply to another circuit board for the motors as they need a bit heavier gauge wire to handle the higher voltage and current.

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