Abstract: An electrostatic drive having a plurality of mover electrodes operatively secured to a mover, and a plurality of stator electrodes operatively secured to a stator. The mover and stator are configured to move relative to each other via electrostatic force generated between the mover electrodes and the stator electrodes. The electrostatic drive includes a driver configured to place the stator electrodes in any of a number of sequential voltage states, each being defined by a combination of LO and HI voltage levels at the individual stator electrodes. Transition from one voltage state to a sequentially adjacent voltage state produces a step size of relative movement between the mover and stator. For each of the sequential voltage states, the driver is further configured to selectively vary voltage applied at one of the stator electrodes to an amount between the LO and the HI voltage levels, in order to produce a proportionally smaller step size.

Abstract: This invention relates to an apparatus and method of using a high frequency, high power, fluid dielectric variable capacitor for an impedance matching network. The apparatus includes of a bow-tie rotary vane, a set of two fixed vanes, and a set of rotating vanes adapted to rotate interdigitally between the fixed vanes. A dielectric fluid is circulated between the fixed vanes and the rotating vanes for cooling the device. This arrangement facilitates production of a device having a higher capacitance and a smaller size, thus making it suitable for use in a matching network.

Abstract: A microcomponent which includes a capacitive component, of at least two elementary capacitors (C1, C2, C3, C4) which are connected in series. Each elementary capacitor is made up of two plates namely: a plate (10) fixed with respect to the rest of the microcomponent; and a second plate (12), part of which is capable of being displaced with respect to the first fixed plate (10) due to the effect of a control signal, so as to vary the value of the capacitance of the elementary capacitor C1. The control signals for the various elementary capacitors are generated independently so as to vary the overall capacitance of the capacitor by independent variation of the capacitances of each elementary capacitor.

Abstract: A microelectro-mechanical device which includes a fixed electrode formed on a substrate, the fixed electrode including a transparent, high resistance layer, and a moveable electrode formed with an anisotropic stress in a predetermined direction and disposed adjacent the fixed electrode. The device includes first and second electrically conductive regions which are isolated from one another by the fixed electrode. The moveable electrode moves to cover the fixed electrode and to electrically couple to the second conductive region, thus electrically coupling the first and second conductive regions, in response to a potential being applied across the fixed and moveable electrodes. The fixed electrode is transparent to electromagnetic signals or waves and the moveable electrode impedes or allows transmission of electromagnetic signals or waves.

Abstract: A high power slide tuning capacitor (200) integrated into a circuit board adapted to function at RF and microwave frequencies. The capacitor (200) includes a dielectric substrate (26) with a cavity (28) cut into a side of the substrate (26); a ground plane (24) mounted on a bottom surface of the dielectric substrate (26); a microstrip patch (22) mounted on a top surface of the dielectric substrate (26) and positioned above the cavity (28); and a movable dielectric stub (30) which engages the cavity (28) such that a variable length of the stub (30) is positioned beneath the microstrip patch (22). The microstrip patch (22) can be coupled to a desired circuit trace (20), effectively forming a shunt capacitor to ground.

Abstract: The invention relates to a method for controlling by electrical means the interelectrode distance of such a micromechanical electrode structure [(7,8)] in which at least one electrode [(7)] is attached elastically suspended on the surrounding structure, whereby the elastic properties of each electrode and the electrical control applied over the electrodes determine the interelectrode distance. According to the invention, the distance between the electrodes [(7,8)] is controlled by controlling the AC control current passing via the electrodes [(7,8)].

Abstract: A tunable capacitor includes a substrate, a stationary electrode and a movable electrode supported by the substrate, piezoelectric actuators that are supported by the substrate and drive the movable electrode, and a dielectric layer interposed between the stationary electrode and the movable electrode.

Abstract: An electrostatic actuator with an intrinsic stress gradient is provided. The electrostatic actuator comprises an electrode and an electrostatically actuated beam fixed at one end relative to the electrode. The electrostatically actuated beam further includes a metal layer made substantially of a single metal with an induced stress gradient therein. The stress gradient in the metal layer determines the initial curvature of the beam. Upon electrostatic actuation of the beam, the beam is deflected from its initial curvature relative to the electrode. In one embodiment, the electrostatically actuated beam is used as a top movable electrode of an electrostatically actuated variable capacitor. The capacitance of the electrostatically actuated capacitor is changed upon electrostatic actuation of the beam.

Abstract: A new type of high-Q variable capacitor includes a substrate, a first electrically conductive layer fixed to the substrate, a dielectric layer fixed to a portion of the electrically conductive layer, and a second electrically conductive layer having an anchor portion and a free portion. The anchor portion is fixed to the dielectric layer and the free portion is initially fixed to the dielectric layer, but is released from the dielectric layer to become separated from the dielectric layer, and wherein an inherent stress profile in the second electrically conductive layer biases the free portion away from the a dielectric layer. When a bias voltage is applied between the first electrically conductive layer and the second electrically conductive layer, electrostatic forces in the free portion bend the free portion towards the first electrically conductive layer, thereby increasing the capacitance of the capacitor.

Abstract: A varactor includes a first capacitor plate, a second capacitor plate, at least one fixed charge holder, and a control electrode. The second capacitor plate is spaced from and movable towards and away from the first capacitor plate. At least one fixed charge holder with an imbedded charge is on at least a portion of the second capacitor plate. The control electrode is spaced from the second capacitor plate. Applying a bias to the control electrode moves the second capacitor plate towards or away from the first capacitor plate depending on the polarity of the applied bias.

Abstract: Several methods and structures for improving the yield of out-of-plane micro-device structures including springs and coils are described. In one method the springs used to form out-of-plane structures are constrained via a tether to avoid bunching and entanglement. The high yield structure may be used in numerous electronic applications such as filter circuits.

Abstract: A method to construct a capacitive transducers comprising the steps of forming over and in a planar surface of a substrate at least one rigid electrode of a variable-area capacitor electrically connected to a location on said substrate reserved for electrode attachment; providing a cooperating flexible electrode with a dielectric layer; and bonding said flexible electrode to said substrate in a surface region surrounding said rigid electrode.

Abstract: A yarn sensor (25) for monitoring at least one parameter of a traveling yarn (17), e.g., in spinning and bobbin-winding machines, has a measuring gap (16) and a housing made of a non-conductive plastic material for containing electronic components. The housing surface is covered by a metallic coating such that the electronic components are surrounded by the coating (21). At least a portion of the surface inside the measuring gap (16) is free of the coating (21). The metallic coating is connected with a heat conductor to remove heat via the metallic coating (21). Undesirable effects on the measurement results can be substantially reduced, and the quality of the measurement results can be increased.

Abstract: Reservoir volume in a drug delivery device is sensed by providing a capacitor, the capacitance of which varies with bellows position or, alternatively, with the amount of propellant liquid absorbed in a dielectric material. In one embodiment, a capacitance is provided between a surface of the bellows, which acts as a first capacitor plate, and a conductive surface disposed proximate the bellows, which acts as a second capacitor plate. As the bellows moves from its extended full position to its collapsed empty position, the area of overlap, and therefore the capacitance between the first and second plates varies from a maximum value to a minimum value. In another embodiment, a variable capacitor is provided with an absorbent material. The absorbent material absorbs the liquid phase of the propellant in the pump housing and acts as a dielectric between two stationary conductive plates provided in the housing. The amount of liquid propellant absorbed in the absorbent material varies with the reservoir volume.

Abstract: A capacitor with protection device is mainly used to distribute power supply, and to protect capacitor load. The invention can not only display electrical characteristics, but also distribute electric power to every loader. Furthermore, it can protect the capacitor and load by a protection device, and it saves the time and money necessary to install a protection element.

Abstract: MEMS devices include a substrate, an anchor attached to the substrate, and a multilayer member attached to the anchor and spaced apart from the substrate. The multilayer member can have a first portion that is remote from the anchor and that curls away from the substrate and a second portion that is adjacent the anchor that contacts the substrate. Related methods are also disclosed.

Abstract: An improved vacuum variable capacitor can include one or more characteristics that provide advantages over previous vacuum variable capacitors. In particular, the vacuum variable capacitor can be constructed so as to enable the capacitance to be adjusted more easily, reduce parasitic electrical characteristics that degrade the performance of the vacuum variable capacitor, increase the strength of the capacitor plates of the vacuum variable capacitor, reduce the size of the vacuum variable capacitor, and/or make the shape of the vacuum variable capacitor more easily integrated into a system of which the vacuum variable capacitor is part.

Abstract: An adjuster nut is rotatably supported to a vacuum container of a vacuum variable capacitor of a vacuum variable capacitor device. The adjuster nut has a nut portion, and a shank made of an insulating material. The shank has a first end integrated with the nut portion and a second end adapted to be directly coupled with a rotational shaft of a driving portion of the vacuum variable capacitor device. Another type of the adjuster nut has a deformable bellows, a nut portion, and a shank made of an insulating material. A second end of the nut portion is coupled with a first end of the bellows. The shank has a first end coupled with a second end of a bellows, and a second end adapted to be directly coupled with the rotational shaft of the driving portion of the vacuum variable capacitor device.

Abstract: An electret transducer with at least one variable area capacitor and a step to provide a contoured region of a rigid capacitor electrode of said variable area capacitor.

Abstract: A micro electro-mechanical systems device having variable capacitance is controllable over the full dynamic range and not subject to the “snap effect” common in the prior art. The device features an electrostatic driver (120) having a driver capacitor of fixed capacitance (121) in series with a second driver capacitor of variable capacitance (126). A MEMS variable capacitor (130) is controlled by applying an actuation voltage potential to the electrostatic driver (120). The electrostatic driver (120) and MEMS variable capacitor (130) are integrated in a single, monolithic device.

Abstract: A MEM capacitor having a capacitance plate nearer a movable plate than a separate bias plate. Voltage potential between the bias plate and movable plate determines the value of capacitance between the movable plate and the capacitance plate. In a preferred MEM capacitor, the movable plate is suspended over two fixed plates, a bias plate and a capacitance plate. The movable plate is disposed opposite both the bias plate and the capacitance plate. A distance between opposing surfaces of the capacitance plate and the movable plate is less than a distance between the bias plate and the capacitance plate. Preferably, the relative difference in distances between the plates is accomplished by a mechanically suspended movable plate that is shaped to have portions in at least two separate planes.

Abstract: A variable capacitor is provided having first and second capacitor plates, a tandem mover and an actuator. The first and second capacitor plates are positioned such that the first and second capacitor plates face one another in a spaced apart relationship. The tandem mover is configured to move the first and second capacitor plates in tandem in response to changes in ambient temperature to maintain a consistent spaced apart relationship between the capacitor plates. The actuator is then configured to vary the spaced apart relationship between the first and second capacitor plates in response to an external input. The capacitance of the variable capacitor can therefore be varied by increasing and decreasing the spaced apart relationship between the first and second capacitor plates.

Abstract: A new type of high-Q variable capacitor includes a substrate, a first electrically conductive layer fixed to the substrate, a dielectric layer fixed to a portion of the electrically conductive layer, and a second electrically conductive layer having an anchor portion and a free portion. The anchor portion is fixed to the dielectric layer and the free portion is initially fixed to the dielectric layer, but is released from the dielectric layer to become separated from the dielectric layer, and wherein an inherent stress profile in the second electrically conductive layer biases the free portion away from the dielectric layer. When a bias voltage is applied between the first electrically conductive layer and the second electrically conductive layer, electrostatic forces in the free portion bend the free portion towards the first electrically conductive layer, thereby increasing the capacitance of the capacitor.

Abstract: A microelectromechanical system (MEMS) tunable capacitor having low loss and a corresponding high Q is provided. The tunable capacitor includes a first substrate having a first capacitor plate disposed thereon. A fixed pivot structure is disposed on the first surface of the first substrate, proximate the first capacitor plate. The fixed pivot structure as a point of attachment for a flexible membrane that extends outward from the fixed pivot and generally overlies the first capacitor plate. A second substrate is attached to the underside of the flexible membrane and a second capacitor plate is disposed thereon such that the first and second capacitor plates face one another in a spaced apart relationship. A MEMS actuator is operably in contact with the flexible membrane for the purpose of providing an actuation force to the flexible membrane, thereby varying the capacitance between the first and second capacitor plates.

Abstract: A MEMS (Micro Electro Mechanical System) electrostatically operated high voltage variable controlled capacitor device is provided. This device can store high energy over a wide range while using relatively low electrostatic operating voltages. The MEMS device comprises a microelectronic substrate, a substrate signal electrode, and one or more substrate control electrodes. The MEMS device also includes a moveable composite overlying the substrate, having a composite signal electrode, one or more composite control electrodes, and a biasing element. In cross-section, the moveable composite comprises at least one electrode layer and, in most instances, a biasing layer. In length, the moveable composite comprises a fixed portion attached to the underlying substrate and a distal portion moveable with respect to the substrate electrode. The distal and/or medial portions of the moveable composite are biased in position when no electrostatic force is applied.

Abstract: The invention relates to a metallization for a film capacitor, wherein a dielectric capacitor film provided with a metallic coating is wound into a capacitor element in the running direction of the capacitor film, whereby the coating is provided with a segmentation.

Abstract: A variable capacitor includes a driver member including one metal sheet, a head having a driver groove provided therein, engagement portions engaged with a rotor, and a spring function portion in pressure-contact with the rotor are integral with each other. The spring function portion includes a first plate portion extending from one end of the head, which is bent in the first bending portion, and elongated, passing a center shaft, and a second plate portion extending from the end of the first plate portion, which is bent in the second bending portion, and elongated, passing the center shaft. The second plate portion functions as a pressure-contact portion for the rotor.

Abstract: MEMS devices include a substrate, an anchor attached to the substrate, and a multilayer member attached to the anchor and spaced apart from the substrate. The multilayer member can have a first portion that is remote from the anchor and that curls away from the substrate and a second portion that is adjacent the anchor that contacts the substrate. Related methods are also disclosed.

Abstract: A vacuum variable capacitor includes a vacuum bellows for allowing a pressure differential between two volumes inside the capacitor, wherein one of the volumes may be a vacuum volume. The vacuum variable capacitor further includes a conductive bellows disposed within the vacuum volume. In such an arrangement, the materials selected for the vacuum bellows and the conductive bellows may be selected to optimize the function of each bellows.

Abstract: A Q-controlled microresonator and devices including such resonators.

Abstract: A variable capacitor having low loss and a correspondingly high Q is provided. In addition to a substrate, the variable capacitor includes at least one substrate electrode and a substrate capacitor plate that are disposed upon the substrate and formed of a low electrical resistance material, such as HTS material or a thick metal layer. The variable capacitor also includes a bimorph member extending outwardly from the substrate and over the at least one substrate electrode. The bimorph member includes first and second layers formed of materials having different coefficients of thermal expansion. The first and second layers of the bimorph member define at least one bimorph electrode and a bimorph capacitor plate such that the establishment of a voltage differential between the substrate electrode and the bimorph electrode moves the bimorph member relative to the substrate electrode, thereby altering the interelectrode spacing as well as the distance between the capacitor plates.

Abstract: First and second wafers are micromachined by standard integrated-circuit fabrication techniques to respectively make first and second component parts of a variable capacitor. A thin flexible membrane in the first wafer is integral with and mechanically supported by the first wafer. A metal pattern on the first wafer includes a first capacitor plate on the membrane. In the second wafer, a well is formed. A metal pattern on the second wafer includes a second capacitor plate in the well. By bonding the two parts together face-to-face, the capacitor plates are positioned in spaced-apart alignment with each other. External electrical connections to the plates are made via bonding-pad portions of the metal patterns on the wafers. In response to electrical control signals, the metal plate on the membrane can be moved toward the other plate, thereby selectively changing the capacitance of the assembly.

Abstract: A capacitor is described, in particular a vacuum capacitor, comprising two electrodes (1, 1′), at least one insulator (5), and means for fastening (4, 4′). A process is proposed according to which the two electrodes (1, 1′) are each produced as one piece of an electrode material through a cold-flow extrusion process. The electrodes so produced are distinguished by a high surface quality. The result of this, in the capacitors produced from such electrodes, is high quality-factors, low temperature coefficients, a high current-carrying capacity, and an excellent dielectric strength, as well as a compact structure with a simultaneous reduction in the number of components required. Capacitors of this type, in particular vacuum capacitors, find application in HF technology for fixed and variable capacitance values.

Abstract: A variable capacitor that provides a full range of capacitance, while reducing the amount of rotation necessary to effect maximum variation in capacitance, and while eliminating any wear-related deterioration in device performance includes at least two coplanar, electrically isolated sets of parallel electroconductive members so configured as to form a fixed set of capacitor plates, each of which may be separately electrically connected to an electrical circuit. A movable group having at least one member including at least one electroconductive area is positioned parallel to, and spaced from, the fixed set of plates. The movable group is adapted for rotation about an axis perpendicular to a surface plane of the first set of plates to vary an amount by which said movable group overlaps the surface of each of said capacitor plates, and thereby provide variable capacitive coupling between the two isolated electroconductive members that comprise the fixed set of capacitor plates.

Abstract: A variable capacitor has a stator, a rotor, and a cover. The stator includes a stator electrode and a stator terminal connected electrically to the stator electrode. The rotor includes a rotor electrode facing the stator electrode with a dielectric disposed therebetween. The cover is shaped so as to accommodate and hold the rotor so that it can be rotated relative to the stator. An adjustment hole is formed in the cover so as to permit insertion of a tool for rotating the rotor. A spring-action portion is formed around the adjustment hole to thereby press the rotor against the stator. The stator terminal is formed so as not to extend onto a stator surface facing an edge portion of the cover, thereby maintaining a relatively long distance between the stator terminal and the edge portion of the cover and that between the stator terminal and the rotor.

Abstract: A microelectro-mechanical device which includes a fixed electrode formed on a substrate, the fixed electrode including a transparent, high resistance layer, and a moveable electrode formed with an anisotropic stress in a predetermined direction and disposed adjacent the fixed electrode. The device includes first and second electrically conductive regions which are isolated from one another by the fixed electrode. The moveable electrode moves to cover the fixed electrode and to electrically couple to the second conductive region, thus electrically coupling the first and second conductive regions, in response to a potential being applied across the fixed and moveable electrodes. The fixed electrode is transparent to electromagnetic signals or waves and the moveable electrode impedes or allows transmission of electromagnetic signals or waves.

Abstract: An array (100) of voltage variable capacitors (110) is provided in which voltage variable capacitors (110) are fabricated with piezoelectric displacement devices (150). Voltage variable capacitors (110) have first plates (120) which are coupled to displacement devices (150). First plates (120) are dielectrically coupled to second plates (130). Displacement device (150) has a stack of metallic layers (154), voltage variable material blocks (152), and voltage supply terminals (170) and (180). Voltage differences are established across voltage variable material blocks (152) using voltage supply terminals (170) and (180). A voltage difference causes a voltage variable material layer to change thickness, and this causes first plate (120) to move relative to second plate (130). Voltage variable material is selected from a group of piezoelectric ceramics, which can include lead-titanate (PbTiO.sub.3), lead-zirconate (PbZrO.sub.3), barium-titanate (BaTiO.sub.3), and lead-zirconate-titanate (PbZr.sub.x Ti.sub.1-x O.

Abstract: An inductance/capacitance (LC) composite module with a built-in variable capacitor and coil is disclosed which includes a dielectric substrate having one principal surface on which a stator-side electrode is formed. Also formed thereon are a first terminal electrode connected to the stator-side electrode and a second terminal electrode independent of the first terminal electrode. The variable capacitor has a rotor of a chosen solid-state dielectric material in contact with the stator-side electrode. This rotor has thereon a rotor-side electrode which opposes the stator-side electrode with at least part of the rotor laid therebetween, thus forming an electrostatic capacitance. A rotatable support member is mounted so that it may rotate about the axis line at right angles to the substrate surface. The support member transmits its rotation to the rotor allowing the rotor to rotate with the support member.

Abstract: A Q-controlled microresonator and devices including such resonators.

Abstract: A laminate capacitor circuit board which permits constants of various kinds of circuit elements to be set by selectively effected connections between wiring layers, and a laminate capacitor circuit board which permits distributed circuit constants in a high-frequency wiring layer sandwiched between two shielding wiring layers to be set as desired. These circuits are formed with at least a pattern of a conductive foil on each dielectric layer, and include a plurality of wiring layers laminated one upon another, a wiring layer for connections laminated to a surface of the plurality of wiring layers laminated one upon another, a plurality of terminal patterns formed on the wiring layer for connections in a state insulated from each other, a plurality of vias for electrically connecting at least two of the plurality of terminal patterns to corresponding ones of the plurality of wiring layers, and connecting means for selectively connecting the plurality of terminal patterns to each other.

Abstract: A reference electrode is fixed on the bottom of a concave portion of a substrate. A movable electrode is provided so that its electrode face faces that of the reference electrode at an interval to form a capacitor by the movable and reference electrodes. A driving electrode for driving the movable electrode is fixed on the substrate at an interval from the movable electrode. The distance 2L between the driving and movable electrodes is twice the distance L between the movable and reference electrodes. An external bias voltage is applied between the driving and movable electrodes to deflect the movable electrode. This doubles the range of the displacement of the movable electrode, thereby increasing the capacity change rate of the variable capacitor.

Abstract: A small variable capacitor including a movable section composed of a movable electrode supported by a supporting section. A driving electrode and a detecting electrode are provided facing the movable electrode. When an external bias voltage is applied between the movable electrode and the driving electrode, Coulomb force is generated between them. Due to that, the movable section is attracted toward the driving electrode while keeping a balance between its own resilience force and the Coulomb force. At this time, part of the movable section facing the detecting element is displaced more than the other part of the movable section facing the driving electrode. Thereby, because an electrostatic capacity between the movable section and the detecting electrode is inversely proportional to the average distance, a large electrostatic capacity may be obtained and variability of the electrostatic capacity becomes large.

Abstract: A tunable electromicromechanical resonator structure incorporates an electrostatic actuator which permits reduction or enhancement of the resonant frequency of the structure. The actuator consists of two sets of opposed electrode fingers, each set having a multiplicity of spaced, parallel fingers. One set is mounted on a movable portion of the resonator structure and one set is mounted on an adjacent fixed base on substrate, with the fingers in opposed relationship and their adjacent ends spaced apart by a gap. An adjustable bias voltage across the sets of electrodes adjusts the resonant frequency of the movable structure.

Abstract: A variable capacitor for a high frequency circuit of an electrical appliance includes a chip capacitor mounted on a multilayer circuit board and interdigital capacitors formed at inner layers of the circuit board. A wiring pattern for soldering the chip capacitor is connected with the interdigital capacitors via through holes formed in the circuit board. Capacitance select portions are cut so that the capacitance best-suited to the circuit is obtained. The through holes connected to the interdigital capacitors of the inner layer are selectively disconnected from the wiring pattern for soldering the chip capacitor, thereby obtaining a variable capacitor capable of absorbing fluctuations of the circuit for selecting the best-suited capacitance.

Abstract: A capacitive bend sensor includes a first element having a comb-patterned portion of conducting material, and a second element having a comb-patterned portion of conducting material. A dielectric material is disposed between the comb-patterned portion of the first element and the comb-patterned portion of the second element. The first element is bonded to the second element such that the comb-patterned portion of the first element slides relative to the comb-patterned portion of the second element when the first and second elements are bent. Bend angle is measured according to the alignment of the comb-patterned portion of the first element and the comb-patterned portion of the second element. The sensor may be coupled to a human finger to measure bend angle of the finger, or may be coupled to a joint of a human body to measure bend angle of the joint.

Abstract: In a multilayer metallisation/dielectric structure on a silicon substrate a trimmable capacitor is formed between two of the higher metallisation layers, with one layer being segmented and the individual segments connected by way of one or more vias and respective narrow links to one terminal of the capacitor. The narrow links are formed from titanium tungsten on the oxide isolated silicon substrate.

Abstract: An electrically controllable variable capacitor includes the interelectrode capacitance of at least one power MOSFET, a capacitance connected in series with the MOSFET and having one terminal connected to the drain or source thereof (the series capacitance), and bias control circuitry for controlling the bias voltage applied to the MOSFET. The voltage rating of the MOSFET, the peak amplitude of the applied ac signal, and the value of the series capacitance determine the range of dc bias voltages over which the MOSFET can be operated, and hence the capacitance range of the variable capacitor. Such a variable capacitance is useful as a tuning capacitor in an electrodeless HID lamp ballast.

Abstract: A capacitive sensor has a pair of plate-shaped electrodes (4) spaced apart from one another and defining a measurement slot (3) therebetween. Guides (5) mask out edge zones of the measurement slot (3) and reduce its width. These guides (5) are formed as the two legs of an elongated U-shaped guiding part (7) which can be inserted into the measurement slot (3) and can be fixed in the latter.

Abstract: A method and system for detecting the presence of an occupant on a vehicle seat is disclosed. The vehicle seat is provided with at least a pair of electrodes which are connected to a detection circuit for detecting a change in capacitance between the electrodes. If the detection circuit detects a sufficiently large change in capacitance, a positive detection signal is produced. To reduce the risk of interference, the electrodes of the detection circuit are substantially insulated from the chassis of the vehicle and its electrical system when the detection circuit is in an active condition.

Abstract: A solid-state fringe effect capacitive proximity sensor is described which lends itself to use for surface mounting and other space constrained applications. The sensor comprises an insulating substrate having a plurality of sensing electrodes formed thereon and without any screen elements therebetween. The electrodes are adapted to measure the proximity distance of a target object (conductive or non-conductive) by means of the fringe capacitance effect created between the electrodes. Capacitance measurement processing circuitry is electrically connected to the plurality of sensory electrodes.