Kinda OT ... motor speed control
On Sun, 09 Oct 2016 08:23:49 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
fired this volley in
:
I THINK he was talking about remoting the speed pot on the VFD. A
relatively simple 3 conductor cable on the "voltage devider".
Possible for sure, but a bit of a pain.
I never read any indications that he was talking about multi-phase
motors. OF COURSE it can be done that way, but all the discussion here
was about chopper-controlled single-phase induction motors.
Which STILL uses a sped control pot There ARE variable frequency
single phase drives - they just have a narrower speed range and
perhaps a diminished starting torque.
That sort doesn't particularly like that sort of control _anyway_, unless
they were designed for high-slip operation (like, say, ceiling fan
motors).
But, again: A properly designed ball mill requires NO speed control over
a fairly wide range of jar sizes.
LLoyd
Because it is basically the linear speed of the inside surface of the
jar that is critical.
|