Abstract: Systems and methods of quasi-resonant induction heating are provided. In particular, a method for evaluating the resonant frequency of a quasi-resonant induction cooking device can be provided. The method can include generating a startup pulse, receiving multiple feedback pulses from a resonant frequency feedback circuit, measuring a pulse width of each of the feedback pulses, calculating an average pulse width based upon the feedback pulses and determining the resonant frequency based at least in part on the average pulse width and a transfer function.

Abstract: Systems and methods of quasi-resonant induction heating are provided. In particular, a method for evaluating the resonant frequency of a quasi-resonant induction cooking device can be provided. The method can include generating a startup pulse, receiving multiple feedback pulses from a resonant frequency feedback circuit, measuring a pulse width of each of the feedback pulses, calculating an average pulse width based upon the feedback pulses and determining the resonant frequency based at least in part on the average pulse width and a transfer function.

Abstract: An apparatus and techniques for detecting unbalanced load in a washing machine are provided. A clothes basket containing a load of clothing and rotatable about an axis is accelerated. As the clothes basket passes a first predetermined rotational speed, one of power and torque applied to the clothes basket is limited. It is determined whether the clothes basket accelerates from the first predetermined to a second predetermined rotational speed within a predetermined time. Failure to reach the second predetermined rotational speed within the predetermined time signifies an out-of-balance condition as to the load of clothing. No resonance of the machine lies between the first and second predetermined rotational speeds. In another aspect, a similar technique can be employed, with or without limiting power or torque, wherein a resonance does lie between the first and second predetermined rotational speeds.

Abstract: An apparatus and techniques for detecting unbalanced load in a washing machine are provided. A clothes basket containing a load of clothing and rotatable about an axis is accelerated. As the clothes basket passes a first predetermined rotational speed, one of power and torque applied to the clothes basket is limited. It is determined whether the clothes basket accelerates from the first predetermined to a second predetermined rotational speed within a predetermined time. Failure to reach the second predetermined rotational speed within the predetermined time signifies an out-of-balance condition as to the load of clothing. No resonance of the machine lies between the first and second predetermined rotational speeds. In another aspect, a similar technique can be employed, with or without limiting power or torque, wherein a resonance does lie between the first and second predetermined rotational speeds.

Abstract: A method and apparatus for measuring a size of a load in a basket that is rotatably supported is presented. The method comprises determining an acceleration energy (AE) required to accelerate the basket; determining a friction energy (FE) required to maintain a stable rotational speed of the basket; subtracting the friction energy (FE) from the acceleration energy (AE) to obtain a load inertial energy (LE); and determining a load size from the load inertial energy (LE).

Abstract: A method and apparatus for measuring a size of a load in a basket that is rotatably supported is presented. The method comprises determining an acceleration energy (AE) required to accelerate the basket; determining a friction energy (FE) required to maintain a stable rotational speed of the basket; subtracting the friction energy (FE) from the acceleration energy (AE) to obtain a load inertial energy (LE); and determining a load size from the load inertial energy (LE).

Abstract: A washing machine is provided that includes measuring a load in a washer with a motor, the method comprising: a) accelerating a load in the washer b) providing a first input voltage and running the motor until a first speed of the motor is stable; c) providing a second input voltage, d) starting a timer, upon providing the second input voltage, and obtaining a first time measurement; e) operating the motor until the load speed responds to the second input voltage to the motor and is stable; f) stopping the timer and obtaining a second time measurement; g) calculating a time differential between the first time measurement and the second time measurement; and h) determining the load size using a load size equation and the time differential.

Abstract: A method and apparatus is provided for determining a measurement of a portion of a load in a basket that is rotatably supported provided, the method includes: a) determining, a dry load measurement; b) spinning, the basket that is rotatably supported in order to gradually remove the liquid from the load, wherein the liquid is removed substantially by centrifugal force on the basket that is rotatably supported; c) determining a wet load measurement, wherein the dry load measurement is less than the wet load measurement; d) comparing the dry load measurement to the wet load measurement to determine a remaining liquid measurement; and e) repeating c) and d) until the remaining liquid measurement substantially is within a predetermined percentage threshold of about 0 percent to about 50 percent of the wet load measurement.