5935 results about "DC motor" patented technology

The present invention relates to a method for control of a direct current motor in one or several fan units, each comprising a fan, which method comprises: generation of a control signal from a first control unit which is external in relation to the said fan unit; transmission of the said control signal to the said fan unit; reception of the transmitted control signal in the said fan unit; interpretation of the said control signal in a second control unit which is arranged in association with the said fan unit; and generation, in the said second control unit, of a supply signal for the said direct current motor, on the basis of the control signal generated by the first control unit and received in the fan unit and on the basis of a supply voltage. According to the invention, the method comprises transmission of the control signal together with the supply voltage over a shared communication link, with the control signal being superposed on the supply voltage. The invention also relates to an arrangement for such control. By means of the invention, improved control is obtained of a motor that can be utilized in a ventilated seat in a vehicle.

A motor driving method for driving a direct-current (DC) motor, designed for avoiding a reverse current induced by the Back Electromotive Force (BEMF), includes providing a driver circuit for driving the DC motor; comparing a signal level of a terminal of the DC motor and a predetermined voltage value to produce a comparing result; and controlling a specific lower gate switch to avoid the occurrence of a reverse current of the DC motor according to the comparing result.

A control circuit for a DC motor, has: a first and second input ports for connection to a DC source; a H-bridge driving circuit, having first and second switches connected in series between the input ports, and third and fourth switches connected in series between the input ports, a first output port between the first and second switches and a second output port between the third and fourth switches, and a shunt circuit and / or a blocking circuit. The motor is connected between the first and second output ports. The shunt circuit is connected between the first second output ports and has a resistance that will decrease in response to BEMF generated by the motor. The blocking circuit is connected in series with the motor between the output ports and has a resistance that increases in response to BEMF generated by the motor.

Methods and apparatus for controlling the operation of, and providing power for and to, implantable ventricular assist devices which includes a pump employing a brushless DC motor-driven blood pump, are disclosed. In one embodiment, a control system for driving an implantable blood pump is provided. The digital processor is responsive to data associated with the operation of the pump received at the data transfer pump, and from program data stored in the memory, (i) to determine therefrom, the identity of the pump, (ii) to determine therefrom, electrical characteristics and features of the identified pump, and (iii) to adaptively generate and apply to the data port, control signals for driving the identified pump.

The present invention provides a rotational magnetic gimbal with an integral magnetic bearing. Brushless DC motor technology provides electromagnetic suspension, using a single electromagnetic actuator to perform both the radial bearing and rotary torque (motoring) functions. An integrated motor and magnetic bearing consistent with the invention comprises a rotor comprising a plurality of permanent magnets and a stator comprising a plurality of independently controlled coil segments magnetically coupled to the permanent magnets. Embodiments may further comprise first and second radial position sensors, the first radial position sensor disposed in or adjacent to a clearance gap between the rotor and the stator for sensing the position of the rotor with respect to the stator along a first axis, and a second radial position sensor disposed in or adjacent to the clearance gap between the rotor and the stator for sensing the position of the rotor with respect to the stator along a second axis. In method form, a method for providing integral electromagnetic motor and bearing functions comprises sensing a first radial position of a rotor, the rotor comprising a plurality of permanent magnets, with respect to a stator along a first axis, the stator comprising a plurality of independently controlled coil segments magnetically coupled to the permanent magnets; and sensing a second radial position of the rotor with respect to the stator along a second axis; and delivering current to at least one coil segment, the amount of current based on at least one sensed position.

A surgical procedure is disclosed utilizing a cordless surgical handpiece powered from a sterile battery pack that contains a battery in condition for immediate use without further charging or sterilization. The battery chemistry is based upon lithium / manganese dioxide, and the battery after a single use may be disposed of into non-hazardous waste. The compact surgical handpiece has a brushless DC motor and a manually operated external trigger for activating and controlling the motor operations. Interengaging sets of contacts on the handpiece and battery are adapted to become lockingly and conductively interengaged upon rotation of the battery pack relative to the handpiece, in a manner that rapidly achieves correct alignment of the parts and also ensures stable mechanical attachment and support during the surgical procedure.

The invention discloses a gear pump used for a microminiature turbo-jet engine, comprising a direct current motor, a pump body, an upper pump cover, a lower pump cover, a shell, a pair of driving and driven gears which are meshed and a driving shaft and a driven shaft. The driving gear is arranged on the driving shaft; the driven gear is arranged on the driven shaft and is aligned and meshed withthe driving gear; the lower pump cover is fixed on the direct current motor, the upper pump cover is connected to the lower pump cover and the plane of the pump body is pressed tightly and sealed so as to lead the structure to be simple; the shell is sleeved at the outside of the lower pump cover; the driving gear and the driving shaft adopt a method of combining clearance fit and a transmission pin to eliminate the installation error of an output shaft of the direct current motor; and an antifriction material is embedded at the positions on the lower pump cover and the upper pump cover corresponding to the driving gear and the driven gear so as to increase the reliability and durability of the gear pump. Most parts of the gear pump adopt aluminium alloy so as to reduce the weight furthest. The gear pump can control the rotating speed of the direct current motor by pulse-width modulation of a single-chip microcontroller and control the flow rate of the gear pump precisely.