Not understanding Pin-out diagrams

227167_1454181677 · June 23, 2019

Hello, everyone!

After wrestling with extensions for years, I've finally decided to create my own PSU cables. I've purchased all tools required, but I'm now learning pins aren't standardized on the PSU side.
I've found my correct pinout for my model of PSU, but I'm slightly confused as to why I'm needing to split my wires. Below is an image showing each pin has a place, but simply in a new location. Can somebody please explain to me why four splits are needed for EVGA G-2 / G-3 PSUs? Again, it appears only the locations change...

227167_1454181677 · June 23, 2019

Actually, after taking a closer look, I think I understand... The back of the PSU actually has 28 pins for the 24 pin... The top part on the left is a standard 24 pin layout, the two images below that belong to the PSU and the extra 4 pins will split off from wires of the same type ... Got it... Sorry... I'd close this thread if I knew how, but I don't see an option. If anybody would like to throw in any tips / advice before I start in a few weeks, I'm all ears! Night, everyone.

PopsicleHustler · June 23, 2019

Splitting voltage rail into multiple wires allows each wire to deliver sufficient amperage without voltage drops. Also there are things like wire size and PCB patch size. Having a single wire/PCB patch delivering 400 watts of power is dangerous because they can catch fire. PSU manufacturers would have to use thicker cables, which are harder to work with. And PCB manufacturers would have to use wider paths which are also inconvenient due to cramped nature of all modern PCBs.

June 23, 2019

Whoever made that diagram does not know what they're doing and shouldn't be trusted.

When you have two SEPARATE wires coming out of the PSU and the CONVERGE to a single pin on the PSU, that extra wire is a SENSE WIRE.

https://www.pickeringtest.com/en-gb/kb/hardware-topics/pxi-instrument-topics/using-the-voltage-sense-connections-power-supply

In other words: The voltage goes down one wire, and is then "sensed" by the other. It quite literally "reports back" the voltage at the load.

According to that drawing, you're just randomly sending voltages down multiple wires to the load for no reason what so ever.

PopsicleHustler is partly correct: More wires means less resistance and thus less voltage drop. But the PIN in the CONNECTOR is the weakest link. Not the wire. You can have three wires coming out of a single pin, but it won't matter if the pin is only engineered to handle the power of one wire!!!