Re: [CAD_CAM_EDM_DRO] DC motor controller

A lot of people are using these-- The control system is an scr one
not filtered .. It is not a pulse width modulation one.

Nothing is wrong with it and it has been made by an excellent
supplier.. Treadmill motors are a mixed bag . Some are fairly
good others are not.

They do have limitations as they are designed to be high speed
units. If run at slower speeds you may (probably will ) see
cogging.

A cogging Or detenting motor is having problems with torque
fluctuations. It acts like motor is running in a gear train where
you can see the motor fluctuating from gear tooth to gear tooth..
Detenting is another way of describing the same thing and may be a
little easier to visualize. --the motor is driving a wheel with a
spring loaded plunger against a mating wheel with a detent in it .
when they engage the drive slows and the motor has to develop more
torque to proceed. so it pulses. It ends up looking mechanical but
is really electrical in origin. There are ways of designing this
out and reducing the effect but the threadmill motors are not
built this way.

To learn a lot about motors go to the Bodine site and download
their handbook. Bodine makes SUPERIOR small motors. www.bodine-
electric.com/Handbook/

I buy stuff from surplus center too.
jesse

On Nov 11, 2006, at 2:10 PM, John Hansford wrote:



Hi Bill,

I found this at surpluscenter...

http://www.surpluscenter.com/item.asp?
UID=2006111113404127&item=11-2269&catname=electric

Be sure to click on the grey tabs that say "more specs" and "wiring".

Hooked up to 110AC your treadmill motor(like mine) would run at 90VDC.
It controls the speed, gives you your DC Voltage, and you can load
it to 5 amps as is before heat trouble sets in. You can add heatsinks
to go up to 10 amps. 90 volts x 10 amps = 900 watts, thats around
1.25 HP.

Depending on what you want to use the motor for, this may or may
NOT be a good solution. I hope someone will jump in here so
Bill doesn't get steered wrong.

John

.





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