摘要:
A sensor assembly for measuring force along an axis (F) comprises an inductance coil extending around the axis (F) for establishing a loop of magnetic flux looping axially through the coil and extending around the axis (F) to define a donut shaped ring of magnetic flux surrounding the axis (F). A core of magnetostrictive material provides a primary path for the magnetic flux in a first portion of the loop of magnetic flux and a magnetic carrier provides a return path for magnetic flux in a second portion of the loop of magnetic flux as the magnetic flux circles the coil through the core and the carrier. A first interface extends radially between the core and the carrier whereby the core and the carrier are urged together at the interface in response to a force applied parallel to the axis (F). Various embodiments or combinations of the core and carrier are illustrated in FIGS. 3–7.
摘要:
A magnetostrictive fluid-pressure sensor includes annular inner and outer cylinders, a first connector, annular second and third connectors, and first and second coils. The inner cylinder surrounds a fluid-receiving bore. At least one of the cylinders is a magnetostrictive cylinder. The first connector connects the first ends of the cylinders and has a first portion extending radially inward of the inner cylinder. The second connector connects the second ends of the cylinders and defines a fluid inlet. The third connector connects the cylinders and is positioned longitudinally between the first and second connectors. The first coil is positioned radially between the inner and outer cylinders and longitudinally between the first and third connectors. The second coil is positioned radially between the inner and outer cylinders and longitudinally between the second and third connectors.
摘要:
An apparatus (10) is set forth for measuring a return signal of a magnetostrictive sensor (20) that detects a force, torque, or pressure. The return signal includes noise, a DC resistance (44), an AC resistance and an inductance and the inductance is shifted ninety degrees from the AC resistance. The apparatus (10) includes a sensor filter (22) to remove the noise from the return signal. A sensor filter (22) shifts the return signal and more specifically, the inductance by an additional angle and the sum of the additional angle and the ninety degrees phase shift is defined as the final detection angle. To detect the inductance at the final detection angle, a wave filter (16) and a reference filter (28) shifts a reference signal by the final detection angle to trigger a first demodulator (26) to detect the inductance at the final detection angle. The inductance detected by the first demodulator (26) varies due to temperature. To remove the temperature from the measured inductance, the apparatus includes a DC detection circuit (42) to detect the DC resistance which is proportional to the temperature across the sensor (20). The DC resistance and the measure inductance are inserted into a correction equation to produce a corrected inductance which is independent of temperature. Instead of inductance, an AC resistance may be used in the equation.
摘要:
A magnetostrictive strain sensor (10) includes a magnetostrictive core (12) comprising a magnetostrictive material, such as a nickel-iron alloy, able to conduct a magnetic flux and whose permeability is alterable by application of a strain. A conductive coil (14) is proximate the magnetostrictive core (12) to generate the magnetic flux when electrically excited. A shell (16) surrounds the conductive coil (14) and the magnetostrictive core (12) for providing a conductive return path for the magnetic flux. An excitation source (18) is electrically connected to the conductive coil (14) for electrically exciting the conductive coil (14) with an alternating current having a constant magnitude. An in-phase voltage circuit (22) is electrically connected across the conductive coil (14). The in-phase voltage circuit (22) senses an in-phase voltage that is in-phase with the alternating current. The in-phase voltage varies correspondingly to the strain subjected to the magnetostrictive core (12). A processor (24) is operatively connected to the in-phase voltage circuit (22) to determine the strain applied to said magnetostrictive core (12) by comparing the in-phase voltage to a predetermined relationship between strain and in-phase voltage.
摘要:
A resistor (having a resistance of Rs) is connected in series with an inductor whose inductance and/or resistance is desired to be determined. An alternating voltage (such as a sinusoidal voltage) is applied across the series-connected resistor and inductor, wherein the alternating voltage has a frequency ω, a unique maximum or minimum value Vm, an average value and a unique crossover of the average value. The voltage Vr is measured across the resistor when the alternating voltage is at its maximum or minimum value. The voltage Vl is measured across the resistor when the alternating voltage is at its average value. The resistance RL of the inductor is calculated from an equation in which RL is a function of Vm, Vr, Rs and Vl. The inductance L of the inductor is calculated from an equation in which L is a function of Vl, Rl, Rs, Vr and ω.
摘要:
A magnetic force sensor and method for measuring a force applied to an object. A magnetostrictive element mounted on at least a portion of the object is subjected to a prestress. A conductive coil is wound around at least a portion of the magnetostrictive element. An excitation source, which includes one of a current source and a voltage source, excites the conductive coil. A detection circuit detects one of an induced voltage across the conductive coil and a voltage drop across a resistor in series with the conductive coil. The detected voltage can be used to determine the applied force. A second coil can be used in a bipolar sensor or to correct for variations in ambient conditions.
摘要:
A magnetostrictive force sensor universally usable in any environment with similar signals unaffected by the surrounding material. To this end, a sensor comprising a shaft of magnetostrictive material with an inductance coil wound around the shaft is provided with a magnetic shell enclosing the coil only or both the coil and the shaft. Upon application of the magnetic field, the resultant flow of magnetic flux is confined to a path through the shaft and the magnetic shell. By confining the magnetic flux path, the dependency of the sensor signal on the surrounding material and environment is essentially eliminated.
摘要:
A thermo-electric device has a seat side and a cabin side for delivering heating and cooling air from a HVAC module to seat passages of a vehicle seat assembly. A selector is included for setting a desired or control temperature Tcontrol of the seat assembly. A comparator is included for determining the temperature difference ΔT between the actual temperature of the seat assembly Tseat and the desired or selected temperature Tcontrol. A controller simultaneously adjusts a proportioning valve and adjusts the electrical current to the thermoelectric device in relationship to one another in response to the temperature difference ΔT.
摘要:
The subject invention provides an assembly for measuring movement of and a torque applied to a shaft extending between first and second ends and being hollow, specifically for measuring rotation and twisting of the shaft. A permanent magnet is disposed within the shaft for producing a parallel magnetic field emanating radially from the shaft. A sensor mechanism is positioned adjacent the shaft to detect the magnetic flux produced in response to the shaft being moved. The sensor mechanism includes a magnetostrictive (MR) material disposed annularly about the shaft and extends between first and second edges. A flux collector extends beyond the first and second edges of the magnetostrictive material to direct the magnetic flux through a Hall sensor to detect an axial component of the magnetic flux in response to twisting. A positional ring extends annularly around and spaced from the shaft and a positional sensor is disposed between the positional ring and the shaft for measuring a radial component of the magnetic flux in response to rotating.
摘要:
A thermoelectric material having enhanced Seebeck coefficient is characterized by a microstructure comprising nanoscale Pb inclusions dispersed in matrix substantially composed of PbTe. The excess Pb is obtained either by adding Pb in an amount greater than the stoichiometric amount needed to form PbTe, or by adding an additive effective to getter Te so as to produce the desired excess. The method is generally applicable to enhance thermoelectric properties of compounds of Pb, Sn or Ge, and Te, Se, or S.