On 06/01/2011 07:36 PM, emc-users-requ...@lists.sourceforge.net wrote: > The resistor I did use when I was building the interface for my mills > spindle, because I read someplace that a dead short could result in field > demagnetization under the right conditions. There I used a 20 ohm 20 watt > resistor, which seems to be major overkill as I can just barely detect that > heat after about 20 starts& stops in as many seconds. There, the stop > down to about 30 rpm is maybe 1/2 second, and another half second has it > stopped. Grabbing the spindle and turning it by hand is like stirring cold > karo syrup. *It seemed counter-intuitive to me, but from reading stepper motor controller data sheets I've found that if you short out a winding, the current takes longer to decay than if you put a resistor across it, and make it pump energy into a higher voltage. I don't know how this applies to the changing fields in a spinning universal motor, though.*
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