Current Set resistors

[xitian]

I just picked up a few gecko vampire drives and want to make sure I'm getting the right current set resistors. Here are my specs:

Power Supply: 63V @ 15 Amps
Stepper(s): 3.1V @ 5 Amps

I'm calculating I need a 120K resistor for each gecko. Would this be the correct one for sale: http://www.jameco.com/webapp/wcs/sto...oductId=690646

If not can someone show me what I need and what I calculated wrong?
Also I read at stepperworld.com you need a power resistor when you are over driving steppers. Is this the power resister talked about above or would this be another resistor I need for each gecko.?

Thanks

[dertsap]

your calculations are correct for the current set resistor
and that is the correct resistor in the link

stepper world boards need power resistors if your bumping up the voltage

your gecko s are chopper drivers and do not need power resistors ,you need only the current resistor which you can get at radio shack

[endo47]

I'm not sure if this is the correct one but here is the link for a 120K resistor. I just bought some from Radio Shack (5 for $.99 ), and the first ones I bought were the 120's not the 120K's. Good luck.

http://www.jameco.com/webapp/wcs/sto...oductId=691366

[xitian]

Originally Posted by dertsap your calculations are correct for the current set resistor and that is the correct resistor in the link stepper world boards need power resistors if your bumping up the voltage your gecko s are chopper drivers and do not need power resistors ,you need only the current resistor which you can get at radio shack

Thanks! I was thinking that they were choppers.