[thuffner3]

I am currently using an older XT styple PSU,
My steppers require 12v and my controller 5v.

I have a new 12v supply but it does not have a 5 v leg as the older XT box. What do I have to do to get a 5v leg to my controller?

TIA
Neil

[Bloy2004]

I think you tap into your computer and get the 5V from the standard four pin connectors that are commonly used for the hard drives,cdroms, floppy, etc. There is 5v and 12v on these connectors. I just took an unused male connector from my junk box and hooked up a wire to the 5V pin and ran the wire out to the controller. Eventually I willl install a connector to the computer case so I just plug the wire in and not thread it out the case.

[thuffner3]

That would be fine if I could convert one of the 25 lines in my parallel cable to 5v. But I don't always use the same computer to function the machine.
From what Ive seen aside from specialty PSU's and computer PSU's, most only have a specified voltage. Could look further and get lucky enough to find one with a dual voltage supply. But I'd like to use what I have on hand.

Neil

[thuffner3]

The below listed link is what I have for a power supply.


http://www.radioshack.com/product.as...%5Fid=22%2D506

[Bloy2004]

Another option:
Jeff from "HobbyCNC" puts a walwart inside his power supply to provide the 5VDC. I guess he just wires it to the main power input line past the fuse. But I am guessing how he wires it.

[Ken_Shea]

Guys just thinking out loud here,
Is it feasible to convert say a HD 12 volt/80 amp DC charger to 24 volt / 40 amp or 36 volt/20 amp ?


Ken

[davesaudio]

if you need a few hundred milli-amps or so why not use a linear
regulator ie 7805 plus a couple small caps etc as per application notes.

[thuffner3]

Originally posted by davesaudio
if you need a few hundred milli-amps or so why not use a linear
regulator ie 7805 plus a couple small caps etc as per application notes.

Do you have some application notes I may follow, lacking in electronic experience. But learning by the seat of my pants.

Neil

[abasir]

Use the following diagram. I think you can get the LM7805 at Radio Shack. I would change the input capacitor to 470uF/50V and output capacitor to 0.47uF/16V for your case. BTW, input is from your 12V supply and output is the 5V you need. :rainfro:

[abasir]

Here's how LM7805 looks like