Power Supply Suggestions please..

[hoppo]

Just wanted to say thanks to you guys on this thread for helping me out with my power supply build. I managed to pull a good case out of the skip at work which I chopped and changed to suit. I used a 750KVA 0-25 0-25 transformer in the end in case I ever add a 4th axis. Wired the two secondaries in series and through a bridge rectifier and a couple of 80v rated capacitors. All working smoothly, giving a nice smooth DC output of circa 75v. I do still need to add a fuse on the output of the secondary, just waiting for the fuse holder to arrive from Farnell and It'll be complete. I've tried it with a couple of my DQ860MA drivers and all working very nicely indeed. Thanks again.

[Clive S]

Re the caps. 80V rated might be a bit low !! I would suggest at least 100V for safety.

[hoppo]

Good advice, I did think it was a little close but I had them to hand, I'll get a couple rated at 100v to replace them eventually, thanks Clive.

[Jonathan]

Good advice, I did think it was a little close but I had them to hand, I'll get a couple rated at 100v to replace them eventually

It is good advice. I also had some 80V capacitors to hand when I made mine, so that's what I used.

[Clive S]

Yes I forgot to say if you have never seen one blow up, the mess they can make in unbelievable !!

[i2i]

one suggestion, it may be a bit late, and i'm no electronic expert. Most systems i've converted have a transformer for the drives and a seperate one for the logic.
There must be a good reason for this as transformers are both heavy and take up valuable space.

[m_c]

Seperate supplies is more a commercial controller thing. You want to be able to kill the movement without killing the controller, just like with Mach/LinuxCNC, you want to kill the machine without killing the computer.

Some will use a seperate supply for the break-out board, as the BOB needs power and it's easier/tidier than trying to get 5v from the computer.