Abstract: A control circuit drives the coil of a contactor in response to a control voltage being applied. The control circuit includes a power supply that produces a regulated output voltage from the control voltage. The onset of the regulated output voltage starts a timer which controls the width of pulses produced by a PWM controller. The pulses control a transistor that applies the control voltage to the coil. Initially the pulses cause a high current to flow through the coil to close the contactor and after an interval of time the timer signals the PWM controller to shorten the pulses which applies lesser current to the coil to keep the contacts closed. A flyback circuit provides a relatively low reverse voltage drop path in parallel with the coil to maintain the electromagnetic field during the periods between the pulses. When the control voltage is removed to open the contactor, the flyback circuit provides a high reverse voltage drop path to promptly dampen the coil current.

Abstract: A control circuit is provided for transferring power and communication signals through a wireless coupling device in a vehicle steering column. The device can comprise a rotary transformer having a primary and secondary magnetic structure respectfully associated with the wheel side and column side of the steering column. A squib power circuit transforms a high energy power signal suitable for firing an air bag from the column side to the wheel side. A low energy power circuit generates a signal from the column side to the wheel side suitable for operating isolated wheel side electronics, such as cruise control and the like. A tone encoder and decoder circuit communicates low level control signals suitable for signalling wheel side commands from the wheel side to the column side. The low energy power circuit and the tone encoder circuit operate simultaneously and continuously without signal debilitating interaction.

Abstract: A system for enabling a vehicle operator to control the speed or rate of raising and lowering of a powered lift window. The actuator or switch includes a pressure responsive variable impedance device comprising a variable resistance in one embodiment and a variable capacitance in another embodiment. Increasing force directly on the variable impedance device by the user's finger or an actuator decreases the impedance which is sensed by a voltage divider which outputs a voltage which increases with increasing force. This latter voltage is compared with the output of a triangle wave oscillator and the output of the comparator is a pulse width modulated signal with pulse-width proportional to applied force. The pulses are applied to a power device (Mosfet) which modulates the duty cycle (%) of the current to the window lift mechanism drive motor to give variable motor speed.

Abstract: A control circuit is provided for transferring power and communication signals through a wireless coupling device in a vehicle steering column. The device can comprise a rotary transformer having a primary and secondary magnetic structure respectfully associated with the wheel side and column side of the steering column. A squib power circuit transforms a high energy power signal suitable for firing an air bag from the column side to the wheel side. A low energy power circuit generates a signal from the column side to the wheel side suitable for operating isolated wheel side electronics, such as cruise control and the like. A tone encoder and decoder circuit communicates low level control signals suitable for signalling wheel side commands from the wheel side to the column side. The low energy power circuit and the tone encoder circuit operate simultaneously and continuously without signal debilitating interaction.

Abstract: A bypass clutch for use in an hydrodynamic torque converter (10) includes a viscous coupling (30) driveably engaged with the torque converter input shell (12) and turbine (18), and a friction clutch (24) driveably engaged with said input shell (12) and turbine (18) in parallel to the viscous coupling (30).

Abstract: A power tool has a variable speed control circuit that comprises a user switch, a motor and a thyristor connected in series between a pair of power supply terminals. A manually variable resistor is connected between a first electrode of the thyristor and a circuit node. A capacitor is coupled between the circuit node and the second thyristor electrode. A bleed-off resistor is connected between second thyristor electrode and the circuit node to provide a path for discharging the capacitor when the user switch is open. A semiconductor trigger device, such as a diac or silicon trigger switch, couples the circuit node to the thyristor gate electrode. The circuit operation ensures that the capacitor charges from substantially the same voltage level at the start of each half-cycle during which the thyristor is to be turned on.

Abstract: A current transformer device is formed on a ceramic substrate which is provided with a plurality of planar conductive tracks formed on a surface of the substrate where the conductive tracks extend substantially radially from an imaginary point on the surface of the substrate. A structure of permeable material layers is then tape cast or epitaxially formed by vapor deposition of a thick film of magnetic ceramic over the major portion of each of the conductive tracks to form a permeable toroidal core. A lead frame is then placed over the core and a plurality of metal conductors are soldered to each of the respective exposed ends of the metal conductive tracks on the substrate to form a toroidal coil surrounding the toroidal core. The required electrical elements to complete the current transformer device are mounted to a second side of the ceramic substrate and electrically connected to the toroidal coil for powering and/or receiving signals therefrom.

Abstract: A current transformer device is formed on a ceramic substrate which is provided with a plurality of planar conductive tracks formed on a surface of the substrate where the conductive tracks extend substantially radially from an imaginary point on the surface of the substrate. A structure of permeable material is then tape cast or epitaxially formed by vapor deposition of a thick film of magnetic ceramic over the major portion of each of the conductive tracks to form a permeable toroidal core. A lead frame is then placed over the core and a plurality of metal conductors are soldered to each of the respective exposed ends of the metal conductive tracks on the substrate. The required electrical elements to complete the current transformer device are mounted to a second side of the ceramic substrate and electrically connected to the toroidal coil for powering and/or receiving signals therefrom.

Abstract: A vibration damper having a rotary input member connectable to the output of an engine and a driven member connectable to the input of a transmission. The vibration damper has a plurality of springs resiliently connecting the rotary input member to the driven member. A first pressure plate is disposed between the rotary input member and the driven member and a second pressure plate is disposed between the driven member and a retainer plate. A spring produces a lateral force urging the first and second pressure plate into frictional engagement with the rotary input member and the driven member. The first and second pressure plates have elongated circumferential slots which receive drive pins attached to the rotary input member and permit the rotary input member to torsionally vibrate relative to the driven member through a predetermined angle with a low frictional lag permitting the springs to absorb a substantial portion of the low amplitude torsional vibrations.

Abstract: An arc detection method and apparatus is provided for an electric circuit having an electrified conductor (46) connecting a voltage source (26) to a load (30). The arc detector includes a field sensor (62) sensing an electromagnetic field established about the conductor by the occurrence of an electrical arc in the circuit, and generating a field responsive signal in response thereto. Arc discrimination circuitry responds to the field sensor and generates a tentative arc signal in response to a given characteristic of the field responsive signal. Arc timing window circuitry responds to the arc discrimination circuitry and generates a confirmed arc signal in response to a given timing characteristic of the tentative arc signal.

Abstract: An arc detection method and apparatus is provided for an electric circuit having an electrified conductor (46) connecting a voltage source (26) to a load (30), the conductor having a line side extending from the arc detector to the voltage source, and a load side extending from the arc detector to the load. The arc detector includes a field sensor (62) sensing the electromagnetic field established about the conductor by the occurrence of an electrical arc in the circuit, and generating a field responsive signal in response thereto. Direction sensing circuitry detects whether the arc is from the load side or the line side, and generates a direction indicative signal.

Abstract: A well work-over drilling rig uses a single cylindrical column forming a mast for assembly and disassembly of a casing, pipe or rod forming a well string in a well bore.The mast supports a hydraulic ram for elevating a crown block having arms radially extending equal distances from the axis of the ram. Cables are supported by sheaves at the outer ends of the arms to permit equal and opposite forces (moments) to be applied to the column by the weight of pipe sections or the complete well string. The column is stabilized by racking pipe sections, including up to the full length of a well string, annularly around the column mast on a rotatable fingerboard, with substantially the full weight of pipe sections on the lower annular support. This avoids the need for lateral guy wires to stabilize the column mast.

Abstract: A controller for a batter-drive DC motor controls the average motor current by switching a series-connected FET on and off with a pulse-width-modulated gate signal. Motor speed is changed by chaning the duty cycle of the signl, which is generated by an oscillator. An undervoltage protection circuit senses the battery voltage and compares it with a reference system that has hysteresis. An overload protection circuit senses the motor current, integrates the sensed signal, and comprares the result with a Zener reference diode that is connected in an amplifier circuit for positive feedback. The oscillators's pulse-width-modulated output, the undervoltage protection circuits's output, and the overload protection circuit's output are input to a "NOR" Logic gate, whose output drives the gate of the FET.

Abstract: The present invention is a current sensor employing a magneto resistive sensor having high fidelity of output. This current sensor includes a magnetic flux concentrator substantially encircling the electrical conductor having magnetic sensing, a magnetic device generating a magnetic field component along an axis offset from the principle axis, a magneto resistive device disposed in the magnetic sensing region, a constant current source supplying a predetermined constant current to said magneto resistive device, and a voltage sensing circuit connected to said magneto resistive device for measuring resistance by measuring a difference voltage induced by said constant current. This measured voltage corresponds to the current through the conductor. The magneto resistive device is formed as a Wheatstone bridge having a first and second pair of opposite terminals.

Abstract: A controller for a battery-driven DC motor controls the average motor current by switching a series-connected FET on and off with a pulse-width-modulated gate signal. Motor speed is changed by changing the duty cycle of the signal, which is generated by an oscillator. An undervoltage protection circuit senses the battery voltage and compares it with a reference system that has hysteresis. An overload protection circuit senses the motor current, integrates the sensed signal, and compares the result with a Zener reference diode that is connected in an amplifier circuit for positive feedback. The oscillator's pulse-width-modulated output, the undervoltage protection circuit's output, and the overload protection circuit's output are input to a "NOR" logic gate, whose output drives the gate of the FET.

Abstract: A current sensor (10) comprising spaced pole pieces (62, 64) and a magnetic shunt (80) bridging the pole pieces within an insulating housing assembly (12) which also contains a magnetoresistive transducer (90) and electronic circuitry (16) for sensing magnetic field intensity between the pole pieces and relating that intensity as electric signals provided at terminals (26) at the exterior of the housing. The transducer senses magnetic field intensity along a principal axis (88). Permanent magnets (94, 96) or induction coils (276, 278) are provided to establish a biasing component of magnetic field intensity along an axis (98) substantially normal to the principal axis to improve sensor sensitivity, range of operation and immunity to current overload.

Abstract: A holder for fishing leaders which permits organizing a tackle box to hold such leaders and prevent the leaders from being tangled up, and in particular is adaptable for use with leaders of substantial lengths and having spinners, double hooks, bait harnesses and other accessories thereon. The leaders are stored in a compact manner and are quickly accessed. The holder has a plurality of retainers arranged so that the hook has to be fastened to a retainer through a tension link and then the leader extended and wrapped around additional posts, and finally the opposite end of the leader can be coupled to a second retainer. The tension link will provide a tension on the leader and keep it properly positioned. The leader holder can be molded directly into a tackle box or can be made as a separate unit.

Abstract: A fully mobil and totally contained well servicing and drilling rig is disclosed having equipment on the rig for automatically handling well elements (pipe, tubing and rods) going into and coming out of a well. The rig provides well element storage racks, cranes for moving well elements onto and off the tracks, transfer means for moving well elements from horizontal to vertical position, well element conveying means for moving elements to and from the transfer means, an automatic manipulator for moving elements into alignment with the well being serviced, automatic hoisting means, means for connecting and disconnecting elements from the element string within the well, driving means for all of the equipment, and control means for sequencing and operating all of the means so that the entire well servicing or drilling can be accomplished without human handling of well elements in the vicinity of the well head and rig.

Abstract: An electrical power shutdown system for an aircraft includes a battery (B), a battery relay (BR), a plurality of aircraft status sensor switches (SSW), an electrical bus (EB) leading to the power utilization system, a main battery switch (BSW), and a control unit (CS). When the status sensor switches indicate shutdown of the aircraft, the control unit activates a timer (TMR) that controls disconnect elements (Q1, IR) to cause deenergization of the battery relay after a time interval if the pilot forgets to open the main battery switch. The control unit (CS) prevents resetting (closing of the battery relay) on momentary interruption of the positive battery power under shutdown conditions but allows such resetting on momentary interruption of such positive power under normal operative conditions and prevents such resetting regardless of the status if the main battery switch is open.

Abstract: An engine starter protective and control module (PCM) and system having a 1/2 second start speed delay timer (DT) and a 30-second crank timer (CT) that are started when a start switch (SS) is closed to control a logic circuit (L) that operates a coil driver (CD) to energize the engine starter motor (ES). An engine speed signal from an engine-driven alternator (ALT) shaped in a wave shaping circuit (WSC) is detected by a crank frequency sensor (CFS) which by-passes the delay timer (DT) to continue the cranking if the engine attains an initial speed adequate for starting, otherwise, if the battery is too low, the delay timer (DT) terminates cranking. A run frequency sensor (RFS) receives the speed signal and provides a lockout signal to the logic circuit (L) when the engine speed reaches run RPM. A crank timer (CT) started by the start switch (SS) times a 30-second cranking cycle and a 2-minute cool-off lockout interval to prevent overheating of the starter motor (ES).