Power supply question

[fordgt72]

Just a quick question to those who know better. I'm kinda a noob when it comes to electronics/electricity. I have a power supply with 4 rails, 1@40v 1@5v 1@+12v and 1@-12v. If I use the +12 and -12 together that would give me 24v right? What sort of problems may I run into with this. Do I run the risk of frying my driver board?

Thanks ahead of time for any assistance.

[Al_The_Man]

You don't mention if these all share the same common? I would assume they do?
You can obtain 24v that way but it all depends on how and what it feeds and if it is a completely isolated circuit, if it is then you should see no problem.
The problem may appear if you operate any of the other supplies into the driver.
Or if you are using either of the +12 -12's to operate any other piece of the equipment.
IOW, the whole picture has to be known before giving a decision.
Al.

[fordgt72]

Al_The_Man: thanks for the quick response. I have a DIY mill that I'm hoping to power with one of the cheap 3axis TB6560 drivers. I haven't pulled it from the box yet, just watched the video that it comes with. I purchased a 24v 10a supply for this setup but it is lost in shipping(trying to resolve). For fear that I got ripped I decided to hopefully make up for it by using this supply.

Not sure of it's origins but it is a hefty sized transformer with a 3x5(give or take) circuit board. The board has 2 6800uf caps and 1 2200uf cap(and then some) on it. It has several wires coming off of it. I got my voltages by measuring from one of the black wires to the others. From black>white=40v black>orange=5v black>yellow=-12v black>green=12v.

Not sure if this means they share a common. I only plan to power the driver with it. I'm not sure what you mean by completely isolated circuit. If you're referring to it having a dedicated line then it won't be isolated.

Thanks again for any help/advice.

[Al_The_Man]

I had assumed it was a switching supply, but if it has a hefty transformer then it is possible it could be a linear supply with separate secondaries.
But if you are just using it for the 24v, then there should be no problem.
Al.

[smarbaga]

if it is a switching psu, the -12v may only be capeable of suppling miliamps. this is normal in computer stuff.

[fordgt72]

Thanks to all who replied. I was able to get a refund for the lost psu. I ordered a new 24v 6.5a off ebay. So I scrapped the idea.

Again thanks for the help.