It would help if we knew what the actual problem was. You can my transformers for domestic 12 volt dichroic lighting so if it's a transformer problem, the easiest solution is to get one of those and keep the 12 volt bulb in the enlarger.
Originally Posted by Stubob
I would also probably do what ic-racer suggests but that doesn't necessarily mean I would suggest someone else does it. It doesn't need to be dodgy or jury-rigged. It can be done properly. Even when something does look decidedly home made, it can still be perfectly safe.