I open up an ATX power supply to use for something else besides computer. Cleaning up the wires, I see there are labels for "-5v" and "-12v". Has anyone ever used -12v and +12v for 24v power? Or is that not a good idea?
You can, when -12 is used as GND reference, all other voltages are referenced to -12.
i.e. +5v will be 17 volts.
larryd:
You can, when -12 is used as GND reference, all other voltages are referenced to -12.i.e. +5v will be 17 volts.
Ok, that's what I thought. I haven't taken too many ATX power supplies apart and did not know if I got a lucky with a surprise 24v output on this one.
I want to find some information from this story.
Teronsabe:
I want to find some information from this story.
This power supply I believe is an AT power supply, which is dated well before ATX power supplies were commonly used. If you want to know more, just crack open a old computer power supply, type in "atx power supply bench" on google and read the basic tutorials.
But do note, the current rating of the minus supplies is probably not that high. And the lowest rating is leading when you put them in series. So although the +12V line is rated for (for example) 20A and the -12V for 1A, you are limited to 1A @ 24V (referenced to the -12V).
Also, a AT(X) supply is referenced to PE. So don't use -12V as GND in a circuit that's for example connected to a computer. This will short it out.
sure, I have used one for a decade...
Once i removed the duck tape someone put over the label on the power supply, it revealed the details of power. I have .5a of wonderful 24v power. Not really enough to do anything with.
The rest of the power good for all the LED desk lighting and plenty of experiments.
I probably want to try out one of those DPS3003 modules. Looks like it has all the other basic limiting and voltage manipuation. Not the greatest thing in the world, but maybe the best for $20 entire dollars can get.