On Wed, 26 Aug 2009 12:34:52 -0700 (PDT), NT
wrote:

On Aug 26, 7:21*pm, T i m wrote:
Hi all,

I am tinkering with the idea of building a test jig and a basic bench
grinder could make the ideal platform.

Am I right in thinking you can make induction motors 'soft start'
(reduced starting torque) by the inclusion of a series resistor?

Cheers, T i m

more or less any motor can be soft started that way


Indeed, but I believe an induction motor is more difficult to speed
control (my ideal solution), hence the soft-start as an acceptable
compromise.

So I use a series resistor to limit the starting torque but I assume
it would also limit the final torque. Then I assume I could either
switch out the starter resistance (or it could be automatically
switched out after a time delay etc [1]) to give me the full power of
the motor if it's unable to reach full revs with less_than_full
torque?

Cheers, T i m

[1] I imagine they make starter relays that may do this already?