power supply voltage question

[Monte]

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

[ger21]

I can't recommend a transformer, but I can tell you do NOT run a Xylotex at more than 30V, or it won't last long at all. They are not available yet, but you might want to look at the new Gecko drives being developed that can handle 50 volts. See the Cheap drive thread in the Gecko section.

[pminmo]

The 3977's of the Xylotex board don't like anything above 35V. Ger21 is correct, if you don't have a circuit to limit max voltage and protect them. In my experiments 27 to 29Vdc is about the upper limit without a clamp circuit.

[Monte]

Thanks for the heads up, I wasn't going to over volt the board. 41vdc is my target with a different driver. Now that I know the specs, I have a voltage and a amperage that are both higher than the Xylotex can handle. I might be building a controller for the Taig now, but it might be for something else down the road.

Monte