I forgot to mention the plug polarity in my response.
For DC the center is usually the + connection, but not
always. Getting it wrong can range from won't work
(but no damage) to letting the magic smoke out and
having it never work again.

For AC it doesn't matter.

Art

"Joe B" wrote in message
...
On Thu, 29 Sep 2005 18:35:38 -0400, "Mike Marlow"
wrote:

What if it's the wrong polarity.
The power supply I have has an end on it where you can switch polarity.
What happens if I choose wrong?