Patent ID: 6051952
Filing Date: 2000-04-18
Classification: H02P

Abstract:
A method for reversing an induction motor adapted to be supplied by an alternating current supply (ac supply), the motor comprising a line winding directly connected to the ac supply for supplying an ac voltage waveform to the line winding, a control winding, and a controller connected between the ac supply and the control winding for applying a control voltage waveform to the control winding to control the operation of the control winding, the method comprising:applying the control voltage waveform to the control winding to effect a reversal of the motor;monitoring the ac voltage waveform and applying a predetermined control voltage waveform to the control winding in response to the monitored ac voltage waveform to effect the reversal; andselecting a predetermined waveform switching pattern from the memory of a microprocessor of the controller and applying the waveform switching pattern to a power switching circuit of the controller to generate the control voltage waveform applied to the control winding.