[stevehertz]

I recently bought a wall wart style power supply that was advertised as being 6V DC with negative on the central pin of the connector, positive on the outer. On receiving the supply I looked at the polarity diagram on the label and it showed positive core voltage - not negative as I needed. However, the last 30cm of the DC connection lead comprised a second, 'added on' series lead. And as I suspected, that short lead was being used to switch polarity. So the unit was exactly as I wanted albeit with a 'misleading' diagram on the wall wart.

The point of this post being to say that such polarity swapping leads are available to make the most of your collection of wall warts and/or to save the hassle of having to cut and resolder the leads on to a replacement (non-moulded) connector. Now, I've done a quick search on Ebay and I can't find a source of such polarity swapping leads, but maybe I'm using the wrong search description. They must be out there somewhere!