RE: dc rotary motor

["sundog" <sundog-at-timeship-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi Marc, all,

  The only problem I could see with using a stepper motor in that the things
are slow.  They are designed to be precision devices, and the speed they
operate at will most likely be too low for a rsg.  You could use a belt
drive and increase the gap rpm, but getting a stepper large enough to drive
it...  You may be best off using an H-bridge to drive the stepper, as it
takes the the delicate solid state count down a bit. And adjusting the speed
via the resistance on the h-bridge. Search the net for stepper motor control
and/or robotics, and check into the H-bridge configuration.  Then you run
into the problem of keeping the disc synced with the mains.  You can easily
find how fast the stepper needs to turn, but keeping it locked to the mains
will be a chore and a half...plus the lack of torque and speed.  A ground
1/4 or 1/3hp motor may be a better choice.....

Just my $.03 (i actually know something about steppers!)
										Caio!
										  Shad

-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, June 07, 2000 1:07 AM
To: tesla-at-pupman-dot-com
Subject: Re: dc rotary motor


Original Poster: "Metlicka Marc" <mystuffs-at-orwell-dot-net>

i have been thinking of using a stepper motor for a sync gap. this would
give variable speed and the actual speed could be judged by the step
rate. also with the use of an "o" scope to see the sine wave, the step
rate could be adjusted for a break at the peak of the wave. the stepper
leads could be in a shielded wire with the shield to ground.
any suggestions on this?
.......marc