Old Stuff : This was posted many years ago to my old-ass website – thought i’d not let it go to waste. This is some time from 2015.


Old Stuff – 12V CPU Rail Monitor

The Idea

This is not a wholly original idea but there is still not much reference to the idea on the internet.

The concept is to insert a current amp meter in line with the 12 volt feed providing the CPU with it’s main source of power. That way the current draw, and hence power, can be shown in real time on the meter. This cable is called ATX12V. It has 4 pins, 2 ground and 2 12 volt feeds.
The ATX standard looks like this

For this project you will need both the male and female plug and socket from the ATX12V standard. Plugs can be found on any ATX power supply, just find a old supply and a pair of cutters. Sockets are a little harder to find as these are not often used. They can be de-soldered from a old motherboard or bought reasonably priced from eBay.