Re: [CAD_CAM_EDM_DRO] Enclosures and Power supplies

On Tue, 30 Sep 2003 21:16:36 -0500, you wrote:

>Well, while I was out shopping yesterday, I happened upon something that
>I hope will be of use.
>
>It was a 3 drive external tape backup unit. So it's a decent sized
>metal case, with a PC style power supply, and switches for overall power
>and drives 1, 2, and 3 (X, Y, and Z?), status LEDs, etc. Fan cooled,
>too. It's even got machined openings and ports for 9 pin, 25 pin, and
>Centronics connectors.
>
>Of course you know what I'm thinking...driver board enclosure and power
>supply. I haven't opened it up yet, but it's probably got +-5 and
>+-12VDC available, at fairly decent amperage. (I have a small machine,
>and don't require a 50A supply)
>
>Is this type of power supply a good choice for driver boards and
>steppers? It seems like, as a computer component, the ripple would have
>to be minimal, at worst.
>
>Anyone else use a PC power supply for this type of purpose? Any hints?

The 12 volts should be ok for the boards you have, but you'd really
like more voltage for better high RPM performance.

The 5 volts can be used to power the on board electronics (remove the
7805 and run a separate wire. However, you will probably have to put
in a few 5 ohm resistors (10 watts) to make the power supply stable.

You'll still need the 5 volt separate supply for the optoisolators for
the computer, but that's no big deal.

Harvey

>
> -- Chuck Knight
>