In reply to Terry Blanton's message of Mon, 22 Jan 2007 19:18:09 -0500: Hi Terry, [snip] >Let's suppose you have a circular magnetic gradient of 1 gauss per >degree which delivers 1 Nm of torque to a rotor. Further suppose >that, at the discontinuity of the gradient, you kick the rotor of a >motor past the "sticky spot" with a mechanical force. > >Now you increase the gradient by a factor of 100. Windage and bearing >resistance do not change. How long and hard must you kick? > >Do not forget to consider that the revolutions of the motor are what >deliver work and the kick is shorter with faster rotation. > >Terry
If the motor is unloaded, it's own inertia should carry it past the sticky spot if it is OU (assuming zero friction). This is because as it accelerates all the energy is stored in the rotor as kinetic energy. If this isn't enough to get it past the sticky spot, then it isn't OU. Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition provides the motivation, Cooperation provides the means.
