I bought an £8 ATX PSU tester from eBay recently.
I had the idea that I could use this as a cheap display panel for a home-built bench power supply which would be based on an ATX PSU plus a Boost/Buck variable voltage+constant current converter. This would save buying separate voltage displays for the PSU outputs (3.3V, 5V, 12V, -12V) and also provide a shunt resistor (which is inside the tester) plus an ATX PSU socket and a warning buzzer if any of the rails were outside of specification, and all for £8.
Note: The shunt resistor is only intended to be powered for a short time and it got too hot if I left it connected for more that 10 minutes.
However, when I tested it on 3 different ATX PSUs, I spotted an issue - can you see the problem in the picture below?
I had the idea that I could use this as a cheap display panel for a home-built bench power supply which would be based on an ATX PSU plus a Boost/Buck variable voltage+constant current converter. This would save buying separate voltage displays for the PSU outputs (3.3V, 5V, 12V, -12V) and also provide a shunt resistor (which is inside the tester) plus an ATX PSU socket and a warning buzzer if any of the rails were outside of specification, and all for £8.
Note: The shunt resistor is only intended to be powered for a short time and it got too hot if I left it connected for more that 10 minutes.
However, when I tested it on 3 different ATX PSUs, I spotted an issue - can you see the problem in the picture below?