Abstract: A high frequency AC probe signal is applied to one coil of a stepper motor to induce a signal on the other coil. The induced signal varies in amplitude according to rotor position. The stepper motor is driven by a microprocessor in microsteps. The position of a mechanical stop is determined by monitoring the induced signal while driving the rotor to the stop. When the induced signal no longer changes in amplitude the number of the last microstep yielding movement is recorded as the rotor position corresponding to the stop position. Also by measuring the induced signal at each microstep over a whole rotor rotation and the signal when the rotor stops, a more precise value of the stop position is determined by interpolation. Alternatively, the flip back position of the gauge and thus the stop position is determined on the basis of the induced signal.
July 26, 1996
Date of Patent:
July 21, 1998
Delco Electronics Corporation
Raymond Lippmann, Gail Monica Sylvester, Michael John Schnars, Jeffrey Lynn Shepard, Ronald Kenneth Selby, James Edward Nelson
Abstract: A cross coil type indicating instrument is improved in that a coil bobbin keeps a torque sufficient to hold a stopper plate as a zero point stopper to prevent a positional deviation of the stopper plate after position adjustment and that a stable rotational torque is kept in the positional adjustment of the stopper plate with a jig to assure a reliable position adjustment. The stopper plate is held between an upper bobbin and a lower bobbin with a pinching pressure to inhibit a vertical motion thereof. Spring pieces are formed on an outer periphery of the stopper plate while contacting with the inner face of the lower bobbin with an elastic force. By a biasing force of the spring pieces, the stopper plate is held in the lower bobbin along matching faces between the upper bobbin and the lower bobbin with a substantially constant holding torque.
Abstract: In a cross coil type indicator having a pair of cross coils arranged in quadrature, a magnet rotor having a shaft and a pointer attached to the shaft and rotatably positioned within the coils, the pointer is positioned to indicate a variable by flowing pulse currents through the coils in which the duty ratio is related to the variable value. Digital data corresponding to the pointer angle is stored as sin or cos .theta. data in a memory such as a read only memory (ROM) to enable simple calculation of pointer position from the duty ratio of the current pulse. The configuration disclosed requires only a minimum memory size. The need for extra memory capacity is minimized by storing, within a sin .theta. and cosine .theta. generating means, only sin .theta. data within the range of .phi..degree..ltoreq..theta..ltoreq.90.degree..
Abstract: The cross coil type meter has a magnet rotor and a stopper plate inside a coil bobbin. The magnet rotor is driven by a combined magnetic field produced by a cross coil wound on the coil bobbin. A pointer on a dial plate is attached to the magnet rotor's shaft so that it can indicate the magnitude of a measured quantity. The stopper plate engages with the magnet rotor to stop the pointer at a zero position on the dial plate. But when due to some assembly errors the stop position of the pointer and the zero position on the dial plate do not agree, the position of engagement between the magnet rotor and the stopper plate can be adjusted by manipulating the stopper plate from outside until the two positions agree.
Abstract: In a cross coil type indicator having a pair of cross coils arranged in quadrature, a magnet rotor having a shaft and a pointer attached to the shaft and rotatably positioned within the coils, the pointer is positioned to indicated a variable by flowing pulse currents through the coils in which the duty ratio is related to the variable value. Digital data corresponding to the pointer angle is stored as sin .THETA. or cos .THETA. data in a read only memory to enable simple calculation of pointer position from the duty ratio of the current pulse. A stop pin is provided to limit rotation of the pointer at the end of the scale; a circuit is provided for determining when the pointer is adjacent to the pin or will be driven against the stop pin, and the drive currents are modified in response to such conditions to reduce repetitive striking of the pin by the pointer and to minimize the force with which the pointer is driven against the pin at the stop pin end of the scale.
Abstract: An indicating gauge for automobiles for displaying the amount of a measurement on a gauge board by a movement. The movement comprises a pair of coils for generating a combined magnetic field in response to a predetermined measurement amount, a magnet rotor having a rotation shaft rotating dependent on the generated magnetic field, a counter shaft rotatably disposed in parallel to the rotating shaft, a pointer mounted on the tip of the counter shaft, a rotation gear secured to the rotation shaft and a counter gear secured to the counter shaft. To fix the pointer to 0 position of the gauge board, a stopper is provided in the counter gear. This obviates the another stopper on the gauge board. The number of parts is reduced, and assembling the gauge can be done easily.
Abstract: A fuel gauge damper circuit takes a variable resistance signal from a fuel tank sending unit, develops an input voltage proportional to the variable resistance and generates a filtered average of the input voltage at the fuel gauge damper output. The circuit damps undesirable large swings in the input voltage caused by "sloshing" in the fuel tank. Additionally, the damper circuit features power-up initialization apparatus for eliminating erroneous gauge indications which would otherwise occur upon the initiation of vehicle engine cranking. Also, a return to zero circuit is provided which drives the fuel gauge to zero after the engine is turned off in order to begin the gauge operation from zero when the engine is turned on.
Abstract: An air-core meter having a two-piece bobbin enclosing and surrounding a moveable magnet within a sealed cavity containing a damping fluid. The magnet is rotated about the axis of a supporting shaft by a plurality of orthogonally related windings disposed about the outer surface of the bobbin. The air-core meter provides improved and simplified assembly, improved reliability and reduced damage in routine operation and service through novel bearing design and bobbin structure. Furthermore, improved meter performance is provided by specific winding geometries and magnetic structure design.
Abstract: A moving coil measuring instrument wherein at least one end of the axis (3) of rotation of the moving coil (1) is supported so as to permit adjustment of that end of the axis (3) in a direction substantially perpendicular to the axis (3), such adjustment correcting for non-ideal operation of the instrument. The adjustment is effected by rotation of a support member (5, 7), defining the one end, rotatably mounted in a frame member (9) of the instrument, the support member (5,7) defining the one end at a location displaced from the axis (31, 37) of rotation of the support member (5, 7).
Abstract: A wye-type air-core gauge system provides magnitude indications of measurands in response to PWM signals generated by a control unit that receives electrical signals from a sensor that represents magnitude variations of the measurand. The size of the stator coils of the gauge makes possible a very low profile gauge suitable for mounting in an instrument cluster.
November 3, 1989
Date of Patent:
April 2, 1991
Paul A. Markow, William Nolle, Charles L. Bell
Abstract: Apparatus for measuring an electrical quantity comprises a fixed body and a movable device having a pivot shaft fixed to an indicator needle which moves in front of a graduated scale. The movable device is pivotably mounted in the fixed body by pivot pins and corresponding bearings. The pivot pins are provided at the ends of the shaft while the bearings face the pins on the fixed body. The movable device is further supported relative to the fixed body by knives and corresponding bearings which receive edges of the knives. The knives are fixed to the movable device and the bearings are provided near the ends of the shaft. The edges of the knives and the pivot pins together with the corresponding bearings are aligned with each other.
Abstract: A taut band meter movement assembly comprising a one piece movement frame functioning to hold and center a magnet core, and hold and center spring members for supporting a ligament wire about which a moving coil rotates. The molded one piece frame holds and centers the magnet with a snap fit between two side members having slot engaging edges for engaging slots in the magnet. For holding and centering the spring members, two pairs of circular flat discs are provided having ring receiving slots between each pair of discs for receiving ring members of said spring members. Rotation of said spring members 90.degree. seat the spring members within a magnet ring which serves to protect the movement assembly from physical damage and shields the magnet from any magnetic influences outside the magnet ring.
Abstract: A drive apparatus for a cross-coil type meter has cross-coils formed of a first and a second coil disposed intersecting at the center thereof. A magnet rotor is disposed in a magnetic field set up by the cross coils, and a measurement is represented in terms of a rotational angle of the magnet rotor. The drive apparatus comprises a first supply means for supplying the first coil with a first square wave current having a duty cycle of a% in accordance with the measurement; a second supply means for supplying the second coil with a second square wave current having a duty cycle of (100-a)% complementary to the first square wave current; and a polarity setting means for setting in accordance with the measurement polarities of the first square wave current and the second square wave current.
Abstract: In the moving magnet type meter of the present invention, the coil mounting portions of a bobbin body are projected outwards in a generally arched shape on the central side to form circular arc-like or inclined surfaces, whereby the bobbin body can be made strong against the external pressure induced by the mounting of coils thereon and can be prevented from being deformed. Further, the upper portion of a movable magnet is centrally formed with an upwardly projecting shaft support portion for supporting a pointer shaft, and a thrust bearing portion is formed in the lower surface of an upper bobbin body portion in an opposed relation to the upper end face of the said shaft support portion through a predetermined slight gap, whereby the pointer shaft can be formed in the shape of a straight rod without forming a reduced-diameter portion serving as a thrust bearing, so the fabrication of the pointer shaft is easy and it is possible to maintain the strength of the pointer shaft itself.
Abstract: A disk for an electric meter includes a solid annulus of a conductive material with a center of the annulus filled with a non-conducting material. The non-conducting material is preferably molded in place both to capture the annulus and to secure a disk shaft into a unitary assembly. The annulus distorts eddy currents at distances from sets of potential and current stators of the electric meter to minimize radial components of eddy currents in the vicinity of neighboring sets of potential and current stators. The reduced radial components of eddy currents reduces the constructive or destructive interaction of the eddy currents with their neighboring sources of flux. Increasing the angular separation of the sets of potential and current stators further reduces interaction.
Abstract: A taut band instrument having a moving coil hung by a pair of taut bands to measure electrical current and the like by way of rotating a moving coil in magnetic field. A pair of boss members are provided to hold the moving coil and the boss members include center holes and projections which are provided under the holes respectively, thereby positioning the taut bands at an accurate position. Balance of the moving portion is obtained by cutting off a part of an arm member belonging to the boss member which is made of synthetic resin to be an integral body.
Abstract: A detection signal of a frequency corresponding to a rotational frequency is applied to a frequency-voltage converter and its converted voltage signal is provided to a sine-cosine current generator, from which sine-wave and cosine-wave currents having sine and cosine values corresponding to the voltage value of the voltage signal are supplied to a cross-coil rotary magnet type indicator for providing an indication of the rotational frequency by a pointer. When the power source is cut off, interruption of the power source voltage supply to the frequency-voltage converter and the sine-cosine current generator is delayed by delay means and, in the delay time, the input to the sine-cosine current generator is reduced, returning the pointer to the zero point. The indicator further includes a zero-resetting magnet which interacts with the rotary magnet to force the pointer to move to said zero point.
Abstract: A taut band type instrument comprising a support member supporting thereon a moving coil, a pair of clips electrically connected to the moving coil and mounted on the support member in mutually spaced relation, a pair of upper and lower boss stoppers each having an integral cylindrical portion with a recess defined axially therein and mounted on a bridge, a pair of tension springs mounted respectively on the boss stoppers, a taut band attached to and disposed between the tension springs under a predetermined tension, and soldered to the clips so as to be positioned in the cylindrical portions of the boss stoppers through the recesses therein, a pointer attachment joined to the support member, and a pointer attached to the pointer attachment. The taut band is cut between the clips after it has been soldered to the clips.
Abstract: In accordance with the invention there is provided an electrical resistance measuring indicating device including a bridge network having on one side thereof a first resistance arm connected to a second resistance arm and on the other side thereof, first voltage arm connected to a second voltage arm, there being between the junction of the first and second resistance arms and the junction of the first and second arms are transisterized amplifier circuit and an undamped indicating means responsive to changes in the balance of the bridge networks so as to indicate or measure the resistance or variation in resistance of a subject such as a body are part connected to the network across one of the resistance arms. The indicating means includes a moving coil meter which includes a metal frame of zero conductivity having a meter coil wound thereon and an indicating needle coupled to the frame.
Abstract: An improved viscous dampening arrangement for a taut-band suspension system in an electrical indicating instrument includes a hub associated with the stator and a turret associated with the rotor. The hub and turret each have central openings for receiving the taut-band. The hub and turret are arranged, in use, in a spaced-apart facing relationship with the facing portions of hub and turret being tapered in a controlled fashion. A viscous dampening fluid is provided between the hub and turret and an anti-wetting agent is applied to the surfaces of the hub and turret where the dampening fluid is not desired. The geometry of the tapers is chosen so as to minimize the effects of longitudinal and radial shocks and vibrations on the electrical indicating instrument.
Abstract: The invention relates to a limited rotation galvanometer having a shaft adapted to be deflected in accordance with an electrical drive signal applied to the galvanometer, the galvanometer comprising a stator assembly formed of at least one stationary permanent magnet and at least one pole piece cooperatively arranged about a hollow bore, a rotor associated with the shaft and mounted to turn in the hollow bore, and an electrical winding wound about the pole piece and adapted to receive the drive signal, this stator assembly and rotor defining magnetic circuitry for operation of the galvanometer, the deflection of the rotor being dependent upon the rigidity of the stator assembly and the value of the torque applied between the stator assembly the rotor by the application of the drive signal to the winding.
Abstract: A time-constant circuit is employed for gradually decreasing the voltage of an input signal carrying information to be indicated by a deflecting coil type meter so that the voltage of an input signal applied to the following driving stage does not abruptly drop to zero although the power switch of the driving circuit is turned off. A timer circuit responsive to the power switch energizes a relay or a switching circuit to supply the driving stage with electrical power not only for the time that the power switch is on but also for an additional interval after the power switch is turned off so that the driving stage is capable of being responsive to the gradually decreasing voltage causing the pointer of the meter to return to the zero point.
Abstract: A compact and symmetrically arranged construction for electrical current indicating meters of small size. The meter construction comprises a concentrically pivoted coil which encircles a rounded magnetic fluxplate.
Abstract: A compact and symmetrically arranged construction for electrical current indicating meters of small size. The novel construction for a meter comprises combinations of magnet components including the matching of a permanent magnet with a flux conducting non-permanent magnetic body.
October 2, 1978
Date of Patent:
February 17, 1981
General Electric Company
William J. Schultz, Carl F. Van Bennekom
Abstract: An electric meter particularly characterized by a small number of moving parts and simplified assembly by virtue of fixed cooperating locating surfaces on the elements and sub-assemblies of the meter. A magnetic circuit including a yoke and magnet are constructed to snap into an insulating base in a predetermined position on the base. A coil assembly initially including integral elements for connection of pivot bearings or taut bands is accurately positioned for rotation on the supporting base by inserting the assembly into the base. Cooperating locating surfaces provide for accurate predetermined positioning of the axis of rotation of the coil relative to the magnetic circuit.
Abstract: A compact and symmetrically arranged construction for electrical current indicating meters of small size. The novel construction for a meter comprises a unitary frame member combined with concentrically arranged components.
October 2, 1978
Date of Patent:
December 2, 1980
General Electric Company
Carl F. Van Bennekom, Donald E. Rogers, Edward F. Scannell
Abstract: Adjustment of an electrical measuring instrument of the D'Arsonval type is achieved by rotation of an annular leaf spring contact mounted to rotate between an annular plate and a flanged eyelet extending through the plate and leaf spring. A conducting coil spring attached to the spring contact transmits rotary orientation of the spring contact to an armature assembly disposed for rotation against the return force of the coil spring in an magnetic field.
Abstract: A meter rotor includes a preferably hollow shaft for caging filaments or ribbons, means such as openings on the shaft for engaging a coil, a pair of axially movable end caps engaging opposing ends of the shaft, a spring associated with each end cap for holding the filaments or ribbons taut but without necessarily deflecting the springs, and means on the end caps for engaging a stator.The rotor cooperates with a stator which has rotor-engaging means corresponding to the stator-engaging means on the end caps. The rotor engaging means are separated by a first distance which is greater than a second distance between the stator engaging means. The first and second distances are in a predetermined relationship so that when the rotor is positioned in the stator and the end caps are moved axially, the stator engaging means engage the stator, thereby deflecting the springs to apply tension to the filaments or ribbons.
Abstract: Adjustment of the zero point of an instrument is achieved by rotation of a rotary element extending through the casing of the instrument. The rotary motion of the rotary element is translated into a lateral motion of an intermediate adjustment element. The lateral motion is a side to side motion within the instrument relative to the sides of the instrument casing. The lateral motion of the intermediate element is in turn translated into a pivot motion of a suspension element of the instrument. The pivoting of the suspension element causes deflection and adjustment of the indicating element of the instrument from which readings of the instrument mechanism are taken.
Abstract: A vibrating coil assembly for mirror galavanometers, light-beam oscillographs and the like having a mirror and a moving coil suspended by taut wires or ribbons. The ends of the wires nearest the moving coil are provided with eyes and a mounting wire is brought through the eyes and a window in the moving coil to form a figure 8 and clamp the moving coil within it. A stiffening tube for receiving the mirror is pushed over a section of the wire adjacent to one eye. The stiffening tube is cast together with the moving coil and the mounting wire by means of a setting compound.
Abstract: The suspension of movable system instruments, for example, a galvanometer, introduces elastic reset torques upon deflection. To compensate for such torques and render the apparatus essentially independent of the deflection torques, an opto-electronic device provides an output signal representative of the deflection which is combined with the deflection voltage applied to the galvanometer to at least in part compensate for the reset torque introduced by the moving system suspension.
Abstract: A compact meter with a unitary bridge including magnet support legs to which a magnet is clamped by a magnetically permeable plate and a U-shaped magnet support. Locating surfaces on the bridge cooperate with locating surfaces on the magnet, on the plate, and on the magnet support to locate these elements with respect to the bridge and the rotor. The magnetically permeable plate extends through the coil, and the region below the magnet is substantially unobstructed so that magnets of different thicknesses can be substituted, while using the same bridge, rotor and coil assembly, and plate. In a preferred embodiment the magnetically permeable plate has offset ends which permit inverting the plate to accommodate magnets of two different thicknesses while alowing the use of the same magnet support. The rotor is of composite, solder-free and cement free construction, and includes a unique clamp together arrangement for securing the several parts of the rotor together in proper positional relationship.
Abstract: An improvement to an electrical measuring instrument having a rotary moving part capable of longitudinal movement in relation to the remainder of the instrument and including a damping arrangement comprising co-operating pads fitted respectively to the moving part and an adjacent fixed part to define a gap between the adjacent surfaces of the pads containing viscous liquid held in position by surface tension, the improvement comprising one of the pads being formed of glass-filled plastics material and the gap, when seen in cross-section, having substantially parallel sides which diverge at the edge of the gap, preferably to define a wide-angled V. Preferably the second pad has a smooth surface and may be formed of a light metal.
Abstract: A pen recorder driving mechanism for deflecting a recorder pen on a writing medium in response to electrical input signals is disclosed. The improved pen recorder driving mechanism includes a novel laminar coil assembly rotatably mounted in a precision air gap between a permanent inner core magnet and a highly permeable outer shell. The coil assembly comprises a coil frame having an inner frame around which the windings of a driving coil are wound and an outer frame overlayered on the windings and the inner frame. The coil frame laminations are rigidified by a bonding material applied to the windings during their assembly. The coil frame is subsequently shaped into a generally rectangular concave convex configuration by stretching the laminations during manufacture with a forming tool. Half shafts and end pieces are attached to the transverse legs of the coil frame after shaping to define the rotational axis of the coil assembly and to provide a mounting structure.
Abstract: A device for providing a displacement representative of the magnitude of a signal. The device typically includes a rotor having a plurality of sections of high permeability material separated by areas of high reluctance. A magnetic flux is applied to a section of the rotor to produce an elastic restraint torque varying with angle, while another high permeability section responds to variations in the magnetic flux caused by the signal to produce a torque representative of the signal magnitude. This latter torque moves the rotor to the point where the restraint torque increases sufficiently to balance the signal torque. The resultant angle of rotation represents signal magnitude. The device may also be operated to provide a signal output representative of an input torque or force.
March 17, 1975
Date of Patent:
August 23, 1977
The Charles Stark Draper Laboratory, Inc.
Abstract: A moving coil instrument with a unique base of nonmagnetic sheet metal construction so arranged that sides of the base can flex to receive and clampingly retain a magnetic circuit, without causing movement of end portions of the base which support the moving coil for pivotal movement. Projections of a casing cooperate with circular mounting ears on the sides of the base to exert an inward force to assist the clamping action of the sides to securely hold the magnetic circuit against movement. A unique unitary sheet metal balance cross and a terminal plate assembly provide for connecting inner ends of taut bands which support the coil for movement. Cooperating tabs and slots on the coil, balance cross, and terminal assembly provide for securing the terminal plate and balance cross at opposite ends of the coil in predetermined locations with respect to the coil.
Abstract: A long-scale moving coil instrument of the type comprising a frame, means including an arcuate core member secured to the frame for forming a magnetic circuit path, and a mounting member carrying a moving coil over the core member and being suspended for rotation relative to the frame by means of tension bands secured to bosses on the mounting member. The instrument is characterized by a pair of boss-stoppers made of an elastic, electrically insulating material. Each boss-stopper supports a tension spring, lies in a through-hole provided in the frame, and has a central passage through which the tension bands extend for connection to the tension springs, the passages additionally receiving the bosses on the coil mounting member to limit movement thereof. With this arrangement, electrical connections to the moving coil may be effected by means of the tension bands while maintaining the electrical connections isolated from the frame with the electrically insulating boss-stoppers.
Abstract: An electric meter particularly characterized by a small number of moving parts and simplified assembly. A coil assembly initially including integral support elements which permit connection of pivot bearings or taut bands is adapted to be accurately positioned for rotation on the supporting base by inserting the assembly into the base. Cooperating locating surfaces on the base and coil assembly provide for accurate positioning of the support elements so the axis of rotation of the coil is in a predetermined position relative to a magnetic circuit of the meter. After insertion of the coil assembly, the bridging elements are severed. A coil support form of unique construction includes motion limiting elements which cooperate with surfaces of the magnetic circuit to limit the permissible extent of movement of the coil, in the event of shock or impact, to positions well within the elastic limit of the supports which mount the coil for rotation.
Abstract: A galvanometer structure is disclosed for high speed deflection of a light beam, such as that from a laser source. A flexible member is secured at one end in a mount of electrically insulating and magnetically inert material, for example, a plastic block. At the free end of the flexible member, a rotor is secured and this, in turn, has fixed thereto a reflecting element, such as a mirror. The flexible member also carries a variable magnetic field producing means which is arranged relative to the flexible member and at the back side of the mirror. A controllable variable current source is connected to the coil on the flexible member. A portion of the flexible member is reduced in cross section at a distance that is intermediate the ends thereof for greater flexibility in the direction of the reduced cross section.