I found my stepper specs, finally. It shows inductance at 1.7mH. I found the Gecko formula for max voltage as 1000(sqrt inductance), that gives me 41. I'm using a Xylotex driver board, rated max 35 vdc. I need a transformer, the calc's I found for that give me 35/1.4=25. My current setup is a toroid that I measured giving 21v, I measured across the cap and got 26. The math says I should be getting 29. Not sure what to think.

I need a bigger transformer, looks like 25 vac out. Besides checking my math, can you recommend a supplier of transformers?

Thanks,
Monte