41 results about "EMF measurement" patented technology

In an imaging apparatus having a toner container, a method of periodically calibrating a back EMF constant Ke used in a speed control circuit of a DC motor used for driving for a toner metering device. To adjust the value of the back EMF constant Ke, the method uses a plurality of sampled back EMF measurements together with a calculated actual speed of rotation of the toner metering device as measured using motion sensor.

There is provided an apparatus, comprising: at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to: perform a set of Earth's magnetic field, EMF, measurements inside a building, wherein each EMF measurement result represents at least one of a magnitude and a direction of the EMF in the building;store the set of EMF measurement results off-line into a memory buffer coupled to the apparatus; and upon detecting a predefined triggering condition, cause a transfer of the stored set of EMF measurement results to a database entity.

A Hall resistance measurement unit measures a Hall resistance value in two or more current directions between a plurality of terminals of the Hall element. A Hall electromotive force measurement unit measures the Hall electromotive force of the Hall element. A temperature measurement unit measures an operating temperature of the Hall element. A compensation signal generation unit compensates the Hall electromotive force on the basis of the Hall resistance value from the Hall resistance measurement unit and a temperature output value from the temperature measurement unit. A compensation coefficient calculation circuit calculates a compensation coefficient on the basis of the Hall resistance value measured by the Hall resistance measurement unit and the temperature output value measured by the temperature measurement unit. The compensation coefficient includes a mechanical stress compensation coefficient and a temperature compensation coefficient.

Provided is an apparatus caused at least to: acquire a set of Earth's magnetic field, EMF, measurement results, wherein each EMF measurement result represents at least one of a magnitude and a direction of the EMF as experienced by a mobile device; perform, on the basis of the set of EMF measurement results, a first observation indicating that the mobile device is currently in motion; acquire a set of inertial measurement results, wherein each inertial measurement result represents at least one of acceleration and angular velocity experienced by the mobile device; perform, on the basis of the set of inertial measurement results, a second observation indicating that the motion of the mobile device does not exceed a predefined stationarity threshold; and determine, on the basis of the first and second observations, that the mobile device is currently located in a transport unit which is moving with respect to surrounding environment.

A magnetic flow metering device and method is disclosed for the measurement of corrosive flow streams. The device utilizes a unibody construction wherein the flow conduit is constructed entirely from an insulative, non-conducting material without resorting to a metallic outer housing. The portions of the electrodes in contact with the flow stream are made of a suitable conductive polymer material, resistant to the corrosive media. The electrodes also feature shields that are molded into the electrode assembly to reduce background electrical noise. The invention also utilizes an electrical configuration that actively drives the electrode shield circuit (electrodes as well as cabling) to provide a more accurate measurement of the electromotive force.

There is provided an apparatus configured to: acquire Earth's magnetic field, EMF, measurement results indicating the EMF measured by a mobile device in a building, wherein the EMF measurements are performed by the mobile device in an unknown three-dimensional orientation in a three-dimensional coordinate system of a person carrying the mobile device along a movement direction of the person; acquire motion data of the mobile device, wherein the motion data is measured by at least one inertial measurement unit comprised in the mobile device; determine at least one angle estimate of a difference between the three-dimensional orientation of the mobile device and at least one dominant movement direction on the basis of at least one feature related to the at least one dominant movement direction of the mobile device; and adjust the acquired EMF measurement results on the basis of the determined at least one angle estimate.

A biological information detection sensor is provided by which it is possible to integrate multiple detection means, and it is possible to measure the biological information that is necessary in accordance with the usage state of the sensor used by the user while avoiding redundant information. The biological information detection sensor includes: a skin condition detection portion measuring at least one of a capacitance and an electric resistance change between engaged comb electrodes; a smell component detection portion measuring an electric resistance in accordance with objects absorbed on a selective sensitive membrane which is formed on a portion of the engaged comb electrodes; a temperature detection portion measuring an ambient temperature based on an electromotive force generated by a thermocouple which is formed by using at least two kinds of metallic materials and which is formed on a portion of the engaged comb electrodes; a switching means SW which compares the electromotive force generated by the thermocouple due to changes of the ambient temperature to a predetermined threshold, detects a contact state with an object having a heat source such as a biological body based on a comparison result and conducts switching operation of ON and OFF of the skin condition detection portion and the smell component detection portion based on the contact state.

The present invention pertains to a Hall electromotive force correction device and Hall electromotive force correction method for highly accurately correcting the magnetic sensitivity of a Hall element by correcting the stress and correcting the temperature, while reducing an increase in layout surface area or increase in current consumed. A Hall resistance measurement unit (13) measures the Hall resistance value (VR) in two or more directions of conduction between a plurality of electrodes belonging to a Hall element (11). A Hall electromotive force measurement unit (14) measures the Hall electromotive force (VH) of the Hall element. A temperature measurement unit (15) measures the ambient temperature of the Hall element. A correction signal generation unit (20) corrects the Hall electromotive force on the basis of the Hall resistance value given by the Hall resistance measurement unit and the temperature output value (T) of the temperature measurement unit. A correction factor computation circuit (21) calculates a correction factor (K) from the Hall resistance value measured by the Hall resistance measurement unit and the temperature output value measured by the temperature measurement unit. The correction factor comprises a stress correction factor (Ksigma) and a temperature correction factor (KT).

Methods and apparatus for a centrifuge motor, which are particularly suited for measuring and calculating the back EMF coefficient (Ke) of the motor and motor temperature.

A magnetic flow metering device and method is disclosed for the measurement of corrosive flow streams. The device utilizes a unibody construction wherein the flow conduit is constructed entirely from an insulative, non-conducting material without resorting to a metallic outer housing. The portions of the electrodes in contact with the flow stream are made of a suitable conductive polymer material, resistant to the corrosive media. The electrodes also feature shields that are molded into the electrode assembly to reduce background electrical noise. The invention also utilizes an electrical configuration that actively drives the electrode shield circuit (electrodes as well as cabling) to provide a more accurate measurement of the electromotive force.

The invention relates to an electromagnetic flowmeter for non-full pipe flow measurement, comprising an electromagnetic flow transducer, an electrical impedance measurement module, an induced electromotive force measurement module and a control and signal processing module. The electromagnetic flowmeter is characterized in that the electromagnetic flow transducer comprises a measuring pipe, an electrode and a magnet exciting coil; the electrical impedance measurement module includes a multi-way switch group (A), an excitation signal source circuit and an electrical impedance measurement circuit; the induced electromotive force measurement module comprises a multi-way switch group (B), an exciting circuit and an induced electromotive force measurement circuit; and the control and signal processing module is in charge of controlling the multi-way switch groups, the electrical impedance measurement module is used for obtaining a plurality of groups of electrical impedance values, and the induced electromotive force measurement module is used for obtaining a plurality of groups of induced electromotive force values, so that the flow rate inside a pipe can be obtained under the conditions of full pipe and non-full pipe. The electromagnetic flowmeter can realize accurate measurement of the flow rate without calibrating different fluid mediums in a state of non-full pipe flow.

The invention discloses a measurement method and system of interphase leakage magnetic fields of transformer windings. The measurement system of the interphase leakage magnetic fields of the transformer windings comprises a power supply, transformer windings electrically connected with the power supply, a short circuiting device communicated with lines between the power supply and the transformer windings, magnetic induction sensors arranged in middle positions of adjacent windings of all transformer windings and used for inducing the leakage magnetic fields between the adjacent windings, an electromotive force measurement device electrically connected with the magnetic induction sensors, as well as a magnetic density calculation device electrically connected with the electromotive force measurement device. By means of the technical scheme, the accuracy of the leakage magnetic fields can be improved.

Disclosed herein is a motor including: a rotor including a shaft; a stator assembly rotatably supporting the rotor; and an air gap measuring module measuring a distance of an air gap between the shaft and the stator assembly by electromotive force generated between the rotor and the stator assembly. The distance of the air gap between the rotor and the stator assembly is measured through the electromotive force generated between the rotor and the stator assembly and the driving of the motor is controlled by the distance of the air gap.

A motor torque measurement system includes a motor in communication with a gyro, a centrifuge rotor connected to the gyro, a housing surrounding the rotor and motor, and a controller in communication with the motor. The controller is connected to a back EMF measurement device, which measures the back EMF of the motor, and is also configured to measure motor rotational speed. The back EMF coefficient (Ke) and motor torque constant (Kt) can be calculated therefrom and the actual motor performance thereby determined. Motor magnet temperature may also be calculated. Back EMF and motor rotational speed measurements may be taken with the motor coasting.

There is provided an apparatus, comprising: at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to: perform a set of Earth's magnetic field, EMF, measurements inside a building, wherein each EMF measurement result represents at least one of a magnitude and a direction of the EMF in the building;store the set of EMF measurement results off-line into a memory buffer coupled to the apparatus; and upon detecting a predefined triggering condition, cause a transfer of the stored set of EMF measurement results to a database entity.

A Hall resistance measurement unit measures a Hall resistance value in two or more current directions between a plurality of terminals of the Hall element. A Hall electromotive force measurement unit measures the Hall electromotive force of the Hall element. A temperature measurement unit measures an operating temperature of the Hall element. A compensation signal generation unit compensates the Hall electromotive force on the basis of the Hall resistance value from the Hall resistance measurement unit and a temperature output value from the temperature measurement unit. A compensation coefficient calculation circuit calculates a compensation coefficient on the basis of the Hall resistance value measured by the Hall resistance measurement unit and the temperature output value measured by the temperature measurement unit. The compensation coefficient includes a mechanical stress compensation coefficient and a temperature compensation coefficient.

The invention discloses a method and a device for measuring slag-iron liquid level information of a hearth of a blast furnace online. High-precision electromotive force signals produced by electromotive force measuring points are used as measuring parameters, a computer system performs procedure code analysis on data of different air ports and different tap holes, and liquid level and dead stock information of the hearth is obtained. The measuring basis is change of heat transfer of a refractory material of the hearth and a furnace shell due to different heat storage capacity of slag-iron, and the measuring value is heat transferred by the refractory material and the furnace shell. The computer system responsible for code processing is used as a data visualization system, the inside of each electromotive force measuring point comprises a resistor, a measuring probe and a circuit, and the electromotive force produced by each electromotive force measuring point is directly analyzed and calculated. With the measuring method and device, the change of the liquid level in the hearth is mastered in real time, the blast furnace is guided to discharge iron and slag timely, and monitoring on the basis of daily operation and realizing of stability and long life of the hearth can be facilitated.

The invention relates to a capacitive type flow meter used for non full package flow measurement, comprising an electromagnetic flow sensor, a capacitance measurement module, an induced electromotive force measurement module and a control and signal processing module. The control and signal processing module controls a multi-way switch block and utilizes the electromagnetic flow sensor and the capacitance measurement module to obtain multiple group of capacitances and utilizes the electromagnetic flow sensor and the induced electromotive force measurement module to obtain multiple group of induced electromotive forces, thus being capable of obtaining in-pipeline flows under two conditions of full package and non full package. The invention can realize precise measurement on current without labelling different fluid mediums under non full package flowing condition and avoids the problems of electrode corrosion, pollution and leakage and influence of pulp fluid noise.

The invention discloses a device and a method for measuring an electromotive force of a fan motor. The method comprises the following steps of: generating a fluid by using a wind tunnel device capable of changing wind quantity; guiding the fan motor to be measured to rotate by the fluid; measuring a three-phase induced voltage of the motor to acquire induced electromotive force constants; and detecting whether the induced electromotive force constants meet requirements. By the method, a stable rotary speed can be obtained quickly by the fan motor to be measured; the measurement of the inducedelectromotive force constants at a rated rotary speed and at a plurality of different rotary speeds is realized without compressed air; key characteristic parameters of the fan motor to be measured are acquired; and the degree of an eddy current effect of the motor can be qualitatively observed.

The invention relates to a superheat degree measurement method implemented based on the seebeck effect. The method comprises the steps that firstly, the input end and the output end of an evaporator pipeline in a refrigerating cycle are connected into electrodes, and therefore the electrodes and the evaporator pipeline make tight contact and form a loop, wherein the electrodes are made of materials which contain metal materials and are different from the materials of the evaporator pipeline; then the electromotive force between the electrodes is measured; finally, the measured electromotive force is converted into temperature difference on the basis of the seebeck effect. The invention further relates to a superheat degree measurement device. The superheat degree measurement device comprises the two electrodes and an electromotive force measurer, wherein the two electrodes are made of materials which contain the metal materials and are different from the materials of the evaporator pipeline in the refrigerating cycle. The two electrodes are connected to the input end and the output end of the evaporator pipeline respectively, and therefore the electrodes and the evaporator pipeline make tight contact to form the loop. The electromotive force measurer is connected with the two electrodes. The superheat degree measurement method and device are achieved based on the seebeck effect, the superheat degree of the refrigerating cycle is achieved with high precision and reliability, and the cost can be significantly reduced.

A contactless integrated circuit (IC) card (11) is comprised of the following: a first antenna coil (102) and a second antenna coil (103) for generating an electromotive force by receiving electromagnetic waves from a reader / writer; a first electromotive force measuring unit (311) and a second electromotive force measuring unit (312) for respectively measuring the electromotive force generated by each of the antenna coils; an electromotive force comparing unit (313) for comparing the characteristics of the electromotive forces which are respectively generated by the respective antenna coils and then measured; and an application selecting / executing unit (215) for selecting one application from a program storing unit (216) based on the comparison made by the electromotive force comparing unit (313) and executing the selected application.

It is presented a motor controller configured to control movement of a motor to a mechanical end position. The motor controller comprises: a motor output configured to control an amount of energy being supplied to the motor; a motor input configured to measure a back electromotive force, EMF, voltage over the motor; and a control unit being configured to control the amount of energy being suppliedon the motor output based on back EMF measurements from the motor input when the motor output is in a state of not supplying energy to the motor wherein the control unit is configured to detect an end position of the motor based on changes of back EMF measurements.

The invention provides a laundry machine shock absorber structure with unbalanced feeling function, which comprises the following parts: cylinder in connection with one side of the laundry machine outer-tub; piston inserted in the cylinder with one side fixing the body case bottom; magnet set on the inner round surface of cylinder; magnet bushing set on the other inner round surface of piston; inductive electromotive force measuring device in connection with magnet bushing to measure inductive electromotive force of magnet bushing in the magnet motion course. The structure comprises the following advantages: stopping the washing and dehydrating operation after measuring the shock value because of shock caused by unbalanced washing articles; generating shock absorber force rapidly to reduce the shock and noise effectively according to the variation of shock values because the inductive electromotive force caused by shock absorber can reduce the shock; providing right and stable shock absorber force to reduce the shock without the relation of temperature variation of inner diameter or inside cylinder and operational time lasting of laundry machine.

The invention discloses a device and a method for measuring the local counter electromotive force of an industrial aluminum electrolytic cell. The device comprises a cell interior region side part isolation frame, a melt body interior reference electrode, an anode guide rod voltage probe, high-temperature-resistant copper wires, a high-frequency digital oscilloscope and an interface module. According to the device and the method, the counter electromotive force is measured based on an outage method, local electrolytes of the replaced anode are insulated from the periphery by utilizing a principle that a replaced anode must be powered off when the electrolytic cell is subjected to anode changing, and the counter electromotive force of the local region is accurately measured at the moment when the replaced anode is powered off so as to obtain the counter electromotive force of the local region in the cell can be obtained. The device and the method have the advantages that the counter electromotive force of the local region of the electrolytic cell can be safely and rapidly measured, meanwhile, each cell is measured once every day by utilizing the anode changing period, normal production of the electrolytic cell cannot be influenced, the algorithm of a control system can be calibrated through the counter electromotive force, and therefore the important practical value can be achieved.

In a described example, an apparatus (800) includes: a FET driver circuit (812) configured to supply current to a coil in a stepper motor, the FET driver circuit (812) configured to regulate the current to the coil using a fixed delta current; a current chopper PWM circuit (810) coupled to the FET driver circuit (812) configured to supply pulses corresponding to a step control signal and a direction control signal; a back electromotive force (BEMF) monitor (822) coupled to the current chopper PWM circuit (810) configured to measure an off time pulse and to output a BEMF monitor signal; and a controller (801) coupled to the current chopper PWM circuit (810) to supply the step and direction control signals and coupled to receive the BEMF monitor signal.

The invention discloses a device and a method for fan motor electromotive force measurement. A wind tunnel which can change the wind amount is used for generating fluid, the fluid is used for guiding a fan motor to be measured to rotate, the motor three-phase induction voltage is measured, the induced electromotive force constant is obtained, and whether the induced electromotive force constant meets requirements is detected. By the aid of the technology, the fan motor to be measured can acquire the stable rotary speed quickly, compressed air is not used, the measurement of the induced electromotive force constant under the rated speed and different rotary speeds is conducted, key characteristic parameters of the fan motor to be measured can be obtained and the motor eddy current effect can be observed qualitatively.

The invention relates to an electromagnetic flowmeter for non-full pipe flow measurement, comprising an electromagnetic flow transducer, an electrical impedance measurement module, an induced electromotive force measurement module and a control and signal processing module. The electromagnetic flowmeter is characterized in that the electromagnetic flow transducer comprises a measuring pipe, an electrode and a magnet exciting coil; the electrical impedance measurement module includes a multi-way switch group A, an excitation signal source circuit and an electrical impedance measurement circuit; the induced electromotive force measurement module comprises a multi-way switch group B, an exciting circuit and an induced electromotive force measurement circuit; and the control and signal processing module is in charge of controlling the multi-way switch group A and the multi-way switch group B, the electrical impedance measurement module is used for obtaining a plurality of groups of electrical impedance values, and the induced electromotive force measurement module is used for obtaining a plurality of groups of induced electromotive force values, so that the flow rate inside a pipe can be obtained under the conditions of full pipe and non-full pipe. The electromagnetic flowmeter can realize accurate measurement of the flow rate without calibrating different fluid mediums in a state of non-full pipe flow.

A system may include a switching device. The switching device may include an armature that may move between a first position that electrically couples the armature to a first contact and a second position that electrically couples the armature to a second contact. The switching device may also include a coil that may receive a voltage that magnetizes a core, thereby causing the armature to move from the first position to the second position. The system may also include a control system that may monitor a voltage waveform associated with the coil during an open operation of the switching device.