On Wednesday, June 01, 2011 11:03:20 PM Jon Elson did opine: > gene heskett wrote: > > Greetings all; > > > > Is anyone aware of a quick & dirty retrofit kit to brake an AC > > universal motor when the power is removed? > > Oh, if you want quick and dirty, I already answered that. If you want a > faster stop, then a > relay that would apply something like 12 VAC from a filament transformer > to the field > winding and connect a resistor across the armature would allow you to > set up a stop that > begins immediately and has a controllable rate of deceleration. But, > that is probably more trouble > than you want to go to. > > Jon > Well, I did the deed, and I have verified that when the switch is off, there is a dead short across the receptacle the motor is plugged into. About 20 tests with the saw motor plugged into it, no effect. Unplug the saw motor and plug in a cheap Skil router I have installed in the right table. Also no effect. Both coast to a stop as usual, taking about 15 seconds for the saw, and at least 10 for the router to come to a complete halt.
Two universal motors in a row with absolutely zero residual magnetism??? Is the grain oriented silicon steel that most of these field stacks are made of for the last 25 years that free of hysteresis? Boggles this old electronics types mind... -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) <http://tinyurl.com/ddg5bz> <http://www.cantrip.org/gatto.html> QOTD: "Sure, I turned down a drink once. Didn't understand the question." ------------------------------------------------------------------------------ Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
