Reverse Glow Guages -- Voltage?

A few months back I bought some reverse glow guage overlays, which for the most part followed the spec in the indiglo guage tech article in that it had the six overlays with wires coming out of each, with each wire having a male/female connector that plugged into a switching power supply box. The power supply box pulled power from a source (I had it wired to the dash light line) and from what I can tell transformed or resisted electricity so that the EL lights wouldn't burn out.

Unfortunately, due to some electrical problems the box burned out. I may have to order another, but I was just wondering if anyone knew the voltage limit / requirement for the guages?** I'd like to just wire them into the power source for my dash lights, completely bypassing the included power box thing (which is now burned out) so that when I flip on my headlights they'll just automatically come on, no needing to turn on the indiglos individually. I just don't want to kill the things.

** bold part indicates the meat of this post in case I went into too much of a tangent

the gauges use a transformer to INCREASE voltage to the limit the manufacter wants it at, there is really no way to determien that unless soem one else has the same gauges by the smae manufacter to check the voltage output . then you would have to make a transformers and your probaly looking at moer then the cost the gauges if you got them fairly cheap.....

It is even more complicated that Brian says.... Not only is the EL gauge voltage much higher than 12 V, but the "control box" also has active current limiting built into it. If you knew the voltage and current requirement of the EL displays, and were fairly good at designing electronic circuits, you could probably build your own "control box".

Thanks for the help guys. I guess I'll just wind up buying a new set eventually (I got mine for like $20). The reason the control box went out probably had something to do with me forgetting to solder and heatshrink my connections to the electrical system after I made sure it worked.