A method of operating a laundry machine. The machine has a pair of rotatable components and is driven by an electronically commutated motor having a stationary assembly with a plurality of winding stages and also having a rotatable assembly adapted to be selectively coupled to at least one of the rotatable components. In this method, a DC voltage for application to the motor is received, and a first control function is imposed on the operation of the machine to control the application of the DC voltage in accordance with a selected one of a plurality of first waveshapes so as to provide a resultant effective voltage to the motor. A second control function is imposed on the operation of the machine through the controlled application of the DC voltage to selectively set the maximum amplitude of the effective voltage, and the winding stages are commutated by applying the effective voltage thereto in sequence whereby the first and second control function jointly determine the angular velocity of the at least one rotatable component. A laundering apparatus, a control system for an electronically commutated motor, and a method of operating an electronically comutated motor are also disclosed.

Laundering apparatus, method of operating a laundry machine, control system for an electronically commutated motor, method of operating an electronically commutated motor, and circuit

Control circuit for an electronically commutated motor which has a rotatable assembly and further has a stationary assembly with a plurality of winding stages having terminals for energization, and switches for applying a voltage to one or more of the terminals of the winding stages at a time and commutating the winding stages in a preselected sequence to rotate the rotatable assembly. A preselected sequence of winding stages are left correspondingly unpowered so that a plurality of the winding stages are unpowered at some time. The winding stages generate back emf signals and also couple electrical signals from each energized winding stage to the unpowered winding stages which signals can interfere with detection of back emf for position sensing purposes. The control circuit includes a first circuit for selecting at least two of the unpowered winding stages which have electrical signals coupled to them that have a predetermined relationship in polarity and magnitude. A second circuit produces an electrical output from the voltages on the winding stage terminals of the winding stages selected, so that the electrical signals coupled from each energized winding stage are substantially canceled when they have the predetermined relationship while the back emf is preserved for position sensing substantially free from interference from the electrical signals that are coupled from each energized winding stage to the unpowered winding stages. Other control circuits, electronically commutated motor systems and methods of control and operation are also disclosed.

Control circuits, electronically commutated motor systems and methods

A method and system for estimating a temperature of an electric machine comprising obtaining a temperature value responsive to a temperature signal from a temperature sensor, the temperature sensor is operatively connected to and transmitting the temperature signal corresponding to a measured temperature to a controller. The controller executes a temperature estimation process; and is operatively connected to a switching device, where the switching device is operatively connected between the electric machine and a power source, the switching device being responsive to the controller. Also disclosed is a storage medium encoded with a machine-readable computer program code for estimating an operating temperature of an electric machine. The storage medium includes instructions for causing controller to implement method for estimating an operating temperature of an electric machine as described above. Additionally disclosed is a computer data signal embodied in a carrier wave for estimating an operating temperature of an electric machine. The computer data signal comprising code configured to cause a controller to implement a method for estimating an operating temperature of an electric machine as described above.

Active temperature estimation for electric machines

Disclosed is an electric motor system with reduced torque ripple comprising a sinusoidally magnetized permanent magnet (66), a sinusoidal inverter (50), a higher resolution position sensor, a composite iron stator yoke (70), a composite reinforced plastic rotor core and shaft (62), and a high gear ratio gear reduction box. The novel combination of magnet, inverter, sensor plastic rotor core and shaft and high gear ratio gear box substantially reduced the torque ripple on the shaft of said motor system.

Torque ripple free electric power steering

A control system and method for an electronically commutated motor having a stationary assembly with a plurality of winding stages for carrying a motor current in response to application of a voltage having a magnitude subject to variations, the motor further having a rotatable assembly. The control system is adapted to receive control pulses having a duty cycle which is a function of a desired operating torque or speed for the motor. The control system and method are responsive to the motor current for generating a pluse width modulated (PWM) series of pulses having a pulse repetition rate having a duty cycle which is a function of the duty cycle of the control pulses. The PWM series of pulses are supplied to the commutating circuit as a pulsed signal whereby the operating torque or speed of the motor is a function of the duty cycle of the control pulses and is substantially independent of variations in the magnitude of the applied voltage. The control system may be part of a draft inducer apparatus or method for use with a combustion chamber having an exhaust outlet including a fan for moving air through the exhaust outlet and thereby to induce a draft in the combustion chamber. A pressure sensor connected to the motor control apparatus may be located within the exhaust outlet.

Control system, electronically commutated motor system, draft inducer apparatus and method

A DC Brushless motor comprising a rotor comprising a permanent magnet, a field coil for producing torque for rotation of said rotor, and Hall generators for detecting a rotational position of said rotor. Two Hall generators are arranged in the periphery of the rotor in a spaced relation of 90*. The field coil comprises two coils connected in parallel with a power source. To produce a torque by means of said respective coils to successively rotate the rotor in the same direction, a driving means is provided to serve to flow an exciting current in a reverse direction by displacement of phase by 180* in the same coil. This driving means is adapted to control a direction of current flowing in the coil by an output of said Hall generators. To maintain a rotational speed of rotor at a constant rate, there are provided means for detecting number of revolution of rotor and speed control means which produces a signal for a constant speed control comparing output from said detector with a reference signal.

DC brushless motor

This specification discloses an improved exposure control device for cameras. The device comprises an aperture mechanism for controlling the quantity of incident light, a photoelectric converter element for receiving a light beam passed through the aperture mechanism to convert it into an electrical signal, a detection circuit for detecting a signal from said element and comparing it with a signal representing the photographing conditions to produce a signal for adjusting the quantity of light passed through said aperture mechanism, a control circuit for receiving the signal from said detection circuit to control and drive said aperture mechanism so that the level of said signal becomes zero, and a phase compensation circuit connected with both said detection circuit and said control circuit. The phase compensation circuit improves the frequency characteristic of the output signal from said detection circuit, thereby preventing the occurrence of phenomena such as hunting and the like and enabling a proper exposure to be provided.

Exposure control device

A control circuit for an electric motor having a plurality of driving coils and rotor driven by each coil is disclosed. The control circuit is provided with a plurality of switching means connected to respective driving coils. Means for generating control signal representative of the rotation of said rotor is connected to at least one of said switching means. Means for connecting said generating means to said switching means is provided so as to turn on one of said switching means and turn off the other of said switching means.

Kinzi Tanikoshi

Papers

DC brushless motor

Exposure control device

Control circuit for electric motors

Steuerschaltung fuer elektromotoren