The invention relates an electrical cleaning and care appliance, pressure alarming method and apparatus for the appliance. Transducer elastic members of the appliance engage in resonance oscillation motion with bending strain characteristics, are symmetrically distributed on the left and right sides of the longitudinal axis (L.sub.2) of a drive shaft, and have approximately equal section moduli in bending, approximately equal lengths, approximately equal deflection amplitudes and opposite flexure directions; the angle between the longitudinal axis (L.sub.1) of a cleaning element and the normal direction of the transducer elastic member plane is 0 to 60; the frequency of the alternating current in a drive coil is a fixed value equal to f.sub.0maxn, where n is a fixed value in the range of 0.3(f.sub.0maxf.sub.0min) to 0.8(f.sub.0maxf.sub.0min). Therefore, the appliance has a higher mechanical efficiency, a simple structure and a lower cost.

A drive device that includes a rotating electric machine having a stator with a winding wound on the stator, a rotor rotatably disposed relative to the stator, and a shaft rotating together with the rotor. The drive device also includes a frame member fixed on the rotating electric machine. The drive device further includes a circuit board fixed on the frame member, with a first surface of the circuit board on a frame member side serving as a heat generation element mount surface. The drive device also has a drive element located on the first surface of the circuit board in a heat dissipatable manner, and serving as a component of an inverter that switches on and off to supply an electric current to the winding.

A motor drive circuit includes: a PWM signal generation part configured to generate a PWM signal based on a count value of a counter; a detection part configured to detect a zero crossing of a counter electromotive voltage generated in a coil of a motor; a prediction part configured to predict an arrival timing of the zero crossing of the counter electromotive voltage; a stop part configured to stop a counting operation of the counter after a first time point going back from the arrival timing predicted by the prediction part; and a reset part configured to reset the count value at a timing at which the detection part detects the zero crossing of the counter electromotive voltage.

An electric circuit for use in the control and drive of at least one electric motor, the circuit comprises a first lane comprising a first set of motor windings that are driven by a motor drive bridge that comprises a network of drive stage switches that selectively connect each phase of the lane to either a first supply voltage or a first supply ground, and further comprising a control circuit that controls the switches of the drive stage, the control circuit being powered by an isolated first lane power supply that has a first floating ground, and a second lane comprising a second set of motor windings that are driven by a motor drive bridge that comprises a network of drive stage switches that selectively connect each phase of the lane to either a supply voltage or a supply ground, and further comprising a control circuit that controls the switches of the drive stage, the control circuit being powered by an isolated second lane power supply that has a second floating ground. The first and second control circuits in use exchange digital control signals such that the control circuit of each lane can monitor the function of the other lane, and the two floating grounds and the two lane grounds are connected together through a potential divider network that holds the two floating grounds at a potential that is between the potential of the lane grounds for the two lanes.

An electric circuit for use in the control and drive of at least one electric motor, the circuit comprises a first lane comprising a first set of motor windings that are driven by a motor drive bridge that comprises a network of drive stage switches that selectively connect each phase of the lane to either a first supply voltage or a first supply ground, and further comprising a control circuit that controls the switches of the drive stage, the control circuit being powered by an isolated first lane power supply that has a first floating ground, and a second lane comprising a second set of motor windings that are driven by a motor drive bridge that comprises a network of drive stage switches that selectively connect each phase of the lane to either a supply voltage or a supply ground, and further comprising a control circuit that controls the switches of the drive stage, the control circuit being powered by an isolated second lane power supply that has a second floating ground. The first and second control circuits in use exchange digital control signals such that the control circuit of each lane can monitor the function of the other lane, and the two floating grounds and the two lane grounds are connected together through a potential divider network that holds the two floating grounds at a potential that is between the potential of the lane grounds for the two lanes.

An abnormality determination means performs detection of abnormality of one of the pairs of detection means at a normal speed, and performs detection of abnormality of the other of the pairs at a speed not higher than the normal speed, and, when a sign of abnormality of the detection means is detected at the normal speed, a CPU performs switching to the other normal pair and continues control, and the abnormality determination means performs detection of abnormality of the other normal pair at the normal speed, and meanwhile, continues to perform detection of abnormality of the abnormal pair at a speed not higher than the normal speed.

An electrical machine comprising: at least one stator, at least one module, the at least one module comprising at least one electromagnetic coil and at least one switch, the at least one module being attached to the at least one stator; at least one rotor with a plurality of magnets attached to the at least one rotor, an integrated electrical differential coupled to at least one of the rotors, the at least one integrated electrical differential permitting the at least one rotor to output at least two rotational outputs to corresponding shafts, wherein the at least two rotational outputs are able to move the shafts at different rotational velocities to one another. The electrical machine is configured to fit into a housing, and that can be retrofitted into a conventional vehicle by replacing the mechanical differential.

In one embodiment, an apparatus includes a first member that supports a magnetic flux carrying member and a second member that supports a magnetic flux generating member disposed for movement relative to the first member. An air gap control system is coupled to at least one of the first member or the second member and includes an air gap control device that is separate from a primary magnetic flux circuit formed between the first member and the second member. The air gap control device is configured to exert a force on one of the first and second members in response to movement of the other of the first and second members in a direction that reduces a distance between the first and second members to maintain a minimum distance between the first and second members and/or substantially center the one of the first and second members within the other.

The invention is related to a drive control for driving a dc motor of an electrical household appliance, in particular a hair cutting device such as an electric razor, shaver or epilator, at constant rotational speed.

A variable magnetization machine controller including a hysteresis control component configured to receive an ideal magnetization state signal, output an actual magnetization signal based on the ideal magnetization state signal for control of a variable magnetization machine, and modify the actual magnetization state signal in accordance with an error value between the ideal magnetization state signal and the actual magnetization state signal.