Abstract: A steam purge method for a dishwasher includes a washing cycle, a steam purge cycle and a rinse cycle. During the steam purge cycle, a dishwasher tub is filled with fluid to a level below a heating element in a wash chamber, heated and at least partially converted to steam in the wash chamber. After the steam purge cycle, the dishwasher is drained and the rinse cycle commences. Optionally, a heated drying cycle may be performed upon termination of the rinse cycle. A single heating element arranged in the wash chamber is utilized for heating washing fluid during each of washing, purging and steam generation cycles, as well as for the heated drying cycle.

Abstract: An electric cooking device with a cooking surface. The cooking surface includes a first heating element positioned under the cooking surface arranged to heat substantially the entire cooking surface to a first power density and a second heating element positioned under a portion the cooking surface arranged to heat approximately half of the cooking surface to a second power density. The second power density can be greater that the first power density. The electric cooking device can include a temperature regulator and a selector connected to the first heating element and the second heating element arranged to selectively connect the first heating element or the second heating element through the temperature regulator to a power source.

Abstract: An overall dishwasher operation cycle includes a washing cycle and a final rinse cycle including steam generation. During the final rinse cycle, a dishwasher tub is filled with fluid, heated and utilized to rinse dishware within the dishwasher. After partially draining the tub, a heating element is actuated so as to transform fluid in the tub into steam for cleansing dishware within the dishwasher. After the steam cycle, the final rinse cycle is completed, with the dishwasher being drained. Optionally, when a heated dry cycle is actuated, the heating element continues to operate to provide drying heat to dishware for a period of time before being deactivated. With this arrangement, a single heating element is utilized for heating washing fluid for washing, rinsing and steam generation, as well as for the heated dry cycle.

Abstract: A steam purge method for a dishwasher includes a washing cycle, a steam purge cycle and a rinse cycle. During the steam purge cycle, a dishwasher tub is filled with fluid to a level below a heating element in a wash chamber, heated and at least partially converted to steam in the wash chamber. After the steam purge cycle, the dishwasher is drained and the rinse cycle commences. Optionally, a heated drying cycle may be performed upon termination of the rinse cycle. A single heating element arranged in the wash chamber is utilized for heating washing fluid during each of washing, purging and steam generation cycles, as well as for the heated drying cycle.

Abstract: An overall dishwasher operation cycle includes a washing cycle and a final rinse cycle including steam generation. During the final rinse cycle, a dishwasher tub is filled with fluid, heated and utilized to rinse dishware within the dishwasher. After partially draining the tub, a heating element is actuated so as to transform fluid in the tub into steam for cleansing dishware within the dishwasher. After the steam cycle, the final rinse cycle is completed, with the dishwasher being drained. Optionally, when a heated dry cycle is actuated, the heating element continues to operate to provide drying heat to dishware for a period of time before being deactivated. With this arrangement, a single heating element is utilized for heating washing fluid for washing, rinsing and steam generation, as well as for the heated dry cycle.

Abstract: A motor controller for a single phase induction motor (SPIM), wherein the SPIM is driven by two windings, a line winding connected to the ac line and a control winding driven by the controller. The SPIM torque and hence the speed and direction is controlled by the voltage output of the controller for all speeds below the synchronous speed (set by ac line frequency). The controller adjusts the amplitude, the phase angle relative to the line winding, and the frequency of the voltage for the desired SPIM responses. The controller can also selectively switch power to the line winding for a different operating mode with both windings at below synchronous speed. Or, the controller can open the connection to the line winding after starting, and operate the SPIM via the control winding at any speed by adjusting the amplitude and frequency of the controller voltage.

Abstract: A motor controller for a single phase induction motor (SPIM), wherein the SPIM is driven by a square wave above or below rated frequencies. The square wave may be shaped by introducing one or more notches to eliminate or suppress undesirable harmonics, to reduce the amplitude of the fundamental, to provide desirable voltage control, or to provide desirable voltage to frequency control. The control topology may include switches, main winding taps and switchable capacitors to accommodate selection between line and square wave driving, temporary capacitance increases, or other advantages.

Abstract: Methods and apparatus are provided wherein air gap fundamental flux magnitude and relative position are determined from stator voltage third harmonic components and stator current in operating alternating current machines having a stator, a rotor and an air gap therebetween. Such determinations have various uses, such as for efficiency control.

Abstract: A method and system for controlling operation of a brushless permanent magnet motor having stator windings in star configuration in which back EMF fundamental and third harmonic components are induced, a rotor which rotates relative to the stator windings, and an inverter operatively coupled to the motor to drive same, wherein a star configuration of resistors is coupled to nodes of the inverter and third harmonic components of the flux density of the motor are obtained from across an artificial neutral node present in a network coupled to the stator phase nodes and either the stator neutral node or a direct current midpoint reference node positioned between the direct current nodes of an inverter used to drive the motor. The network preferably is a stator network of resistors each of which is coupled between one stator phase node and the artificial neutral node.

Abstract: A method and apparatus for controlling operation of a brushless permanent magnet motor wherein a signal containing third harmonic component of the motor flux density is acquired and filtered to isolate the third harmonic components, the filtered third harmonic components are integrated to produce a time integral signal, the back EMF of one stator phase is sensed and the resulting EMF signal is filtered zero crossings of the filtered signals are sensed and then employed to drive an inverter controller.

Abstract: A method and system for sensing the rotor speed of a brushless permanent magnet motor wherein a signal containing isolated third harmonic components of the flux density is acquired, and the absolute values of the maximas of the signal are measured, the last measured absolute maxima representing the current rotor speed of the motor.

Abstract: A method and apparatus for controlling torque by correcting slip gain error in an operating induction motor is provided. This is accomplished by measuring the amplitude and position of a flux in the motor such as rotor flux. Rotor flux position and amplitude can be estimated from the air gap flux. The slip gain can then be corrected in a single step or a few steps to provide a deadbeat control.

Abstract: Methods and apparatus are provided wherein air gap flux magnitude and relative position are determined from stator voltage harmonic components and stator current in operating alternating current machines having a stator, a rotor and an air gap therebetween. Such determinations have various uses, such as for efficiency control. Various new and improved efficiency controllers are provided which utilize these measurements.