Voltage Or Current Level Discriminators Patents (Class 361/187)
  • Patent number: 5268811
    Abstract: A refrigerator controller which can positively lock and unlock a door thereof in accordance with a command signal from a host-computer connected therewith. The refrigerator controller includes a power supply voltage indicating device. A DC power supply is charged by a DC power source and energizes a door lock mechanism activating device to lock and unlock the door. DC voltage generated by the DC power supply rises as it is charged by the DC power source. The door lock mechanism activating device can be energized to positively lock and unlock the door by being fed with a predetermined lower limit voltage. Only when the DC voltage generated by the DC power supply is no lower than the predetermined lower limit voltage is the door lock mechanism activating device energized by the DC power supply to lock and unlock the door of the refrigerator in accordance with the command signal.
    Type: Grant
    Filed: December 9, 1991
    Date of Patent: December 7, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Masahiko Maeda
  • Patent number: 5251093
    Abstract: A simplified self-latching relay switching circuit includes a switch, a power shunt circuit including a power node and a shunting device for shunting power from the node to ground, a relay for latching power into the circuit, and a passive circuit which operates the shunting device. When the switch is activated a first time, power is applied to the power shunt circuit, and the node voltage rises according to an RC time constant. The passive circuit is clamped to the node, so a voltage in the passive circuit is prevented from rising rapidly. When the node voltage reaches a threshold value, the relay is activated, latching power into the power shunt circuit. If the switch is then activated a second time, the clamp no longer restrains the passive circuit voltage from rising rapidly. The rapid rise of the passive circuit voltage activates the shunting device, which deactivates the relay to unlatch power to the power shunt circuit, and shunts the node voltage to ground.
    Type: Grant
    Filed: May 24, 1991
    Date of Patent: October 5, 1993
    Assignee: SpaTron Corporation
    Inventor: John A. Dickey
  • Patent number: 5247419
    Abstract: A low voltage switchgear with a single or multipole contact arrangement (1) with a corresponding number of fixed contacts (2) and movable contacts (3), a magnet armature (4) that moves the movable contacts (3), at least one magnet coil (5) that is energized by direct current and a setpoint switch release (9).
    Type: Grant
    Filed: October 28, 1991
    Date of Patent: September 21, 1993
    Inventor: Ernst H. Grundmann
  • Patent number: 5241218
    Abstract: A solenoid valve includes a monitoring circuit adapted to sense the current drop that occurs through the solenoid coil when the solenoid armature moves correctly, sensing of the drop being used to cause a neon to glow continuously so as to indicate correct operation of the solenoid. If the drop is not sensed, the neon is caused to blink so as to indicate incorrect operation of the solenoid. The circuit may in addition or alternatively be arranged to generate a voltage signal, upon correct operation of the solenoid, for transmission to a remotely located programmable logic controller used to control operation of the valve and like valves that form part of a pneumatically controlled machine.
    Type: Grant
    Filed: February 10, 1992
    Date of Patent: August 31, 1993
    Assignee: Norgren Martonair Limited
    Inventor: Michael Page
  • Patent number: 5218509
    Abstract: An electrically operated control device and system for an appliance and method of operating the same are provided, the system comprising a power source of alternating electrical current that has a repeating voltage wave cycle and a repeating current wave cycle, a load for using the electrical current to provide an output of the load for the appliance, a relay having normally open contacts and a coil for closing the contacts only when the coil is energized, an electrical circuit for interconnecting the power source to the load through the contacts only when the contacts are closed, and a control unit for causing the coil to close the contacts substantially at a certain point on the voltage wave cycle each time the relay coil closes the contacts from the open condition thereof whereby the current flow through the contacts at each closing thereof is at substantially a desired level thereof.
    Type: Grant
    Filed: November 15, 1991
    Date of Patent: June 8, 1993
    Assignee: Robertshaw Controls Company
    Inventor: Daniel L. Fowler
  • Patent number: 5214561
    Abstract: A current control circuit for controlling a current supplied to the coil 3 of an electromagnetic type actuator includes a power transistor 2 and a current detecting resistor 4 coupled in series with the coil 3. The voltage across the current detecting resistor 4 is amplified by a differential amplifier 10 and held by a capacitor 8 of a peak hold circuit 6. The input pulse signal A is smoothed by a smoothing circuit 14. A differential amplifier 18 compares the outputs C of the smoothing circuit 14 with that D of the peak hold circuit 6. The output of an OR gate 20 turns on the power transistor 2 either when the input pulse A or the output of the differential amplifier 18 is at the high level. The voltage held across the capacitor 8 is reset by the transistor 9 in response to the output of the OR gate 20. The duty factor of the power transistor 2 is automatically adjusted to compensate for the variations in the circuit characteristics.
    Type: Grant
    Filed: October 29, 1991
    Date of Patent: May 25, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Shigeki Morita
  • Patent number: 5204633
    Abstract: An electromagnetic contactor assembly with a sensing circuit for determining contactor state based upon the reluctance of the contactor coil. The coil has an electromagnetic coil and a movable contact separated from the coil by a gap when the coil is not energized. Energizing the coil causes the movable contact to close the gap and contact the coil. The determination of the relationship between the reluctance in the coil when the gap is in an open and closed state allows contactor gap status to be measured by measuring the coil inductance. A sensing circuit is added to the drive circuit to measure changes in AC current during the pulse cycle which holds the contacts in this closed position. The sensing circuit measures the AC current and is able to signal contactor status based on that value.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: April 20, 1993
    Assignee: International Business Machines Corporation
    Inventors: Steven J. Ahladas, Edward J. Seminaro
  • Patent number: 5196983
    Abstract: A shutter, positioned between an electronic imaging device (such as a laser printer) and a film processor, is actuated by a solenoid which is driven by a driver network which isolates the solenoid coil when it is deactuated. If, after deactuation, a jam occurs, such that the shutter does not close completely, the jam is detected by a solenoid engagement sensing circuit. The sensing circuit includes a function generator, an operational amplifier having the solenoid coil connected between its input and output, an envelope detector and a comparator. The comparator produces a jam signal in response to an increase in the voltage detected by the presence of the solenoid plunger within the solenoid coil.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: March 23, 1993
    Assignee: Eastman Kodak Company
    Inventor: Paul B. Stumpf
  • Patent number: 5142435
    Abstract: An apparatus is provided for precharging a filter capacitor to prevent damage to a set of contacts resulting from arcing across the contacts. Included is a coil, a set of contacts, and a battery, such that the contacts and filter capacitor are connected in series and the series connected combination is connected in parallel across the battery. Also included is a switch, and a microprocessor for producing a triggering signal responsive to the closure of the switch. A driving circuit receives the triggering signal and responsively produces a charging signal. A charging circuit receives the charging signal and responsively charges the filter capacitor. Thereafter, the microprocessor produces an energizing signal causing the coil to become energized and the contacts to responsively close. By precharging the filter capacitor before the closure of the contacts, the voltage potential across the contacts is reduced. Therefore, no damage occurs due to arcing across the contacts.
    Type: Grant
    Filed: June 4, 1990
    Date of Patent: August 25, 1992
    Assignee: Caterpillar Industrial Inc.
    Inventors: Kenneth A. Baumgartner, William Pickering, Arthur Wild
  • Patent number: 5113308
    Abstract: An actuator with a built-in reed switch includes a solenoid, a plunger made of magnetic material and movable within a coil of the solenoid, a plunger receiver made of magnetic material and fixedly mounted in the solenoid coil, a magnetic responsive reed switch connected in series to the solenoid coil and disposed near a gap between the plunger and the plunger receiver, and a sensor terminal branched from a junction between the solenoid coil and the reed switch, whereby contacts of the reed switch are closed by a magnetic field generated when a current flows through the sensor terminal in the solenoid coil. The actuator shifts from high sensitivity to lower sensitivity and supplies a sufficient driving force as an actuator.
    Type: Grant
    Filed: August 31, 1990
    Date of Patent: May 12, 1992
    Assignee: Uchiya Thermostat Co.
    Inventor: Hideaki Takeda
  • Patent number: 5099187
    Abstract: A power connect safety and connection interlock system is shown for use with inverters and other DC loads (16) which include capacitor filter banks (14) at their DC inputs. A safety circuit (20) operates a spring (26) biased, solenoid (22) driven mechanical connection interference (24) which prevents mating and therefore electrical connection between the power contactor halves (11, 13) of the main power contacts (12) until the capacitor bank is safely precharged through auxiliary contacts (18). When the DC load (16) is shut down, the capacitor bank (14) is automatically discharged through a discharging power resistor (66) by a MOSFET transistor (60) through a discharging power resistor (66) only when both the main power contacts and auxiliary contacts are disconnected.
    Type: Grant
    Filed: March 21, 1990
    Date of Patent: March 24, 1992
    Assignee: California Institute of Technology
    Inventor: Wally E. Rippel
  • Patent number: 5055962
    Abstract: The operation of an electromechanical relay is synchronized with the power line waveform where an electrical power supply is supplied from a source to an electrical load. The current voltage supplied to the load is characterized by a power line waveform. An electromechanical relay is positioned between the power supply and the load where contacts of the relay are opened and closed to interrupt and supply power to the load. A microcontroller is positioned between a power source and the electromechanical relay and actuates the relay so that the contacts are closed or opened at a preselected point on the power line waveform. Closure of the contacts at the preselected point is accelerated by supplying an increased power signal to the relay coil and thereafter returning the signal to the rated power.
    Type: Grant
    Filed: February 21, 1989
    Date of Patent: October 8, 1991
    Assignee: Digital Appliance Controls, Inc.
    Inventors: Gregory A. Peterson, Timothy Graff
  • Patent number: 5053911
    Abstract: A method and apparatus for electronically detecting when a solenoid has closed, or nearly closed, indirectly senses changes in the inductance of the solenoid's coil as the solenoid closes. When the inductance has changed by a selected amount, the solenoid is assumed to have closed, or nearly closed, and current through the coil is promptly reduced. Preferably, changes in the inductance of the coil are sensed by establishing a plurality of current peaks in the coil, and sensing the current's decay time between peaks. When the decay time of a measured current peak exceeds the decay time of a previously measured current peak by a selected amount, it is assumed that the solenoid has closed, or nearly closed.
    Type: Grant
    Filed: June 2, 1989
    Date of Patent: October 1, 1991
    Assignee: Motorola, Inc.
    Inventors: James W. Kopec, Philip Herbert
  • Patent number: 5040089
    Abstract: A relay including an internal power reducing mechanism for automatically reducing the relay's power consumption without the need for any periphral power reducing circuits. The relay includes a pair of relay contacts for alternately opening and closing an elctromagnetic coil for generating a magnetic force, a switch member and at least one coil terminal for controlling the resistance of, and thus the current level in, the electromagnetic coil, after the relay is energized. To reduce the power consumption of the relay, in response to the magnetic force of the electromagnetic coil, the movable contact plate simultaneously moves one of the relay contacts with respect to the other and the switch member with respect to the coil terminal. By this movement of the movable contact plate, the pair of relay contacts are closed and an additional electromagnetic coil or a resistor is connected in series with the electromagnetic coil, thus increasing the effective electrical resistance of the electromagnetic coil.
    Type: Grant
    Filed: September 23, 1987
    Date of Patent: August 13, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Akimasa Sasaki
  • Patent number: 5029040
    Abstract: An output circuit having a fail-safe function with: a control signal generating circuit which generates a control signal to control the current of a load and includes an operational amplifier which amplifies a difference between a control value and a feedback value to produce the control signal; a drive circuit which drives a load according to the control signal from the operational amplifier; an output current detecting circuit for detecting a current in a load solenoid and adding an offset current to the detected current, with the output of the output current detecting circuit being fed back to the control voltage generating circuit as the feedback value.
    Type: Grant
    Filed: March 27, 1989
    Date of Patent: July 2, 1991
    Assignee: Aisin Seiki K.K.
    Inventors: Naoyuki Ito, Nobuyasu Suzumura
  • Patent number: 5018043
    Abstract: A removable modular control device for a contactor apparatus having in a casing, power switches actuated by an electromagnet, the coil of which is connected to two external connecting terminals accessible from the exterior through two respective openings provided on the upper face of the casing, each of these terminals having one clamping screw accessible through one opening formed in the front face of the casing. The control device includes a selector which is lodged in an insulating case provided with two rigid projecting pins adapted to be clamped in the connecting terminals, this selector being connected between the projecting pins and input terminals disposed on the upper face of the insulating case.
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: May 21, 1991
    Assignee: Telemecanique
    Inventor: Dominique Moreau
  • Patent number: 5014157
    Abstract: An apparatus for controlling an electric installation is obtained by assembling a removable modular control device on a contactor. The lower face of this control device is provided with two rigid projecting pins located so as to be engaged and clamped in two respective control terminals of the contactor. These projecting pins are connected to two respective input terminals provided on the upper face of the control device, by an electric circuit having an elementary function.
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: May 7, 1991
    Assignee: Telemecanique
    Inventor: Dominique Moreau
  • Patent number: 5008773
    Abstract: A solenoid valve control circuit for operatively connecting a battery to a solenoid to energize the solenoid to actuate a valve includes a coulomb controlling circuit for controllably supplying electric charge to the solenoid in accordance with predetermined criteria.
    Type: Grant
    Filed: November 21, 1988
    Date of Patent: April 16, 1991
    Assignee: Toto, Ltd.
    Inventors: Takao Yoshida, Toshio Ikeda, Takhiro Douke, Toshio Eki
  • Patent number: 4980794
    Abstract: A motor controller or contactor is disclosed which utilizes a non-saturating current transformer for sensing the amount of current flowing in the electrical conductor connected to the contactor. The current sensor is made of homogeneous sintered powdered metal having evenly distributed microscopic air gaps therein which increase the reluctance of the magnetic circuit but resist the influence of stray magnetic flux. This increased reluctance prevents magnetic saturation over a wide range of input current and allows the secondary of the transducer to produce a voltage which is proportional to the derivative of the primary current, that is the current being sensed by the transducer. The aforementioned voltage is linearly proportional to the derivative of the current over a wide range of primary current values. This voltage is integrated to produce an output signal which is directly proportional to the aforementioned primary current over the wide range of current values.
    Type: Grant
    Filed: April 20, 1989
    Date of Patent: December 25, 1990
    Assignee: Westinghouse Electric Corp.
    Inventor: Joseph C. Engel
  • Patent number: 4975801
    Abstract: An automatic bypass for studio TV operation of linear devices (noise suppressors correction, etc.) having the advantage, unlike the known devices in this field, of reacting in case of processing unit supply failures and taking into consideration the change of the output signal parameters as a result of deteriorated operation or dropping of the output signal due to defect. The system provides stable switching when there is unstable or intermittent supply which may comprise the signal transmission. The electromagnetic relay of the bypass is connected to negative and positive supply poles connected to a two-stage differential amplifier coupled to the signal output of a processing unit, and the actuation of the electromagnetic relay is actuated across a voltage translator and electronic switches connected in series, the output of the first switch is also connected to the control input of voltage translator and to ground across a capacitor.
    Type: Grant
    Filed: January 9, 1989
    Date of Patent: December 4, 1990
    Assignee: Bulgarska Televisia Kam Komitet SA Televisia I Radio
    Inventors: Emil P. Vladkov, Dobri D. Mihaylov
  • Patent number: 4972293
    Abstract: A code system for a device (30) that exhibits an input-output relationship characterized by an off-set and substantially linear performance (gain) comprising a resistor network (20) in cirucit with the device's coil (22), indicative of the device's GAIN and OFF-SET wherein the values of GAIN and OFF-SET are intrinsically coded within the value of a single resistor.
    Type: Grant
    Filed: July 31, 1989
    Date of Patent: November 20, 1990
    Assignee: Allied-Signal Inc.
    Inventor: Douglas R. Verner
  • Patent number: 4970623
    Abstract: A circuit and method which are operative to activate a peripheral device, such as a printer, in response to a current surge in a parent device, such as a computer or word processor. The circuit includes a detector which is operative to detect a surge in current demanded by the parent device and further comprises electronic switching circuity, including a comparator, connectec to the detector and responsive to an output signal from the detector for activating the peripheral device immediately after the occurrence of the current surge in the parent device. in this manner, the present invention allows the peripheral device to remain inoperable and quiet and consume no power until such time that it is needed and without requiring an operator to expend the time and effort to turn on a power switch for the peripheral device.
    Type: Grant
    Filed: December 29, 1988
    Date of Patent: November 13, 1990
    Assignee: Hewlett-Packard Company
    Inventor: Robert R. Pintar
  • Patent number: 4967309
    Abstract: A driver circuit for an inductive load, such as a solenoid winding, includes flyback and energization current sensors which respectively sense the current through the coil during flyback and energization. The flyback current sensor includes a flyback current resistor disposed in the flyback current path of the winding for producing a flyback signal proportional to the flyback current. The energization current sensor includes an energization current resistor disposed within the energization current path of the winding. The energization current resistor is adapted to produce an energization signal in response to the energization current flowing through the winding. Control of the solenoid winding is effected by a switch which connects and disconnects the winding from a power source in response to the duty factor of a control signal. A first summing amplifier receives the flyback and energization signals and produces an actual current signal in response to the received signals.
    Type: Grant
    Filed: December 26, 1989
    Date of Patent: October 30, 1990
    Assignee: Caterpillar Inc.
    Inventor: John P. Hoffman
  • Patent number: 4964014
    Abstract: A solenoid current control system includes a microprocessor which periodically generates a desired peak current value and which energizes the solenoid coil. Current through the coil is sensed via a series resistor and the sensed current is compared to the desired peak current by comparator. The comparator generates an interrupt signal when the sensed current reaches the desired peak value. The interrupt signal is applied to the microprocessor which responds by de-energizing the coil.
    Type: Grant
    Filed: January 6, 1989
    Date of Patent: October 16, 1990
    Assignee: Deere & Company
    Inventors: Thomas E. Boe, Vijay M. Dharia
  • Patent number: 4961051
    Abstract: By providing control logic for initiating a predetermined test sequence depending upon the known state of a relay, a unique testing circuit is attained whereby the relay drivers connected to the opposed sides of the relay coil are fully evaluated without causing the relay to be activated. In the preferred embodiment, the relay comprises a latching-type relay and the relay drivers comprise separate high-power CMOS devices. In this configuration, the control logic separately activates each transistor of each of the high-power CMOS devices without causing the relay to be switched between its two alternate configurations. Furthermore, the control logic originally sets the latching-type relay into one of its two configurations and then shuts off the power until activated for initiating the test sequence. In addition, the control logic is employed to check each transistor during the test sequence and assure its operation.
    Type: Grant
    Filed: November 14, 1989
    Date of Patent: October 2, 1990
    Assignee: Alcatel NA, Inc.
    Inventor: Michael O. Tjebben
  • Patent number: 4959746
    Abstract: A contact protective circuit for a relay detects a transient in the relay operating coil and turns on a low resistance power MOSFET in shunt relation with the contacts before the contacts close or open whereby arcing or deposition of metal on the contracts is avoided. Timing circuitry is provided for controlling the MOSFET to conduct large direct currents for short periods of time. In one embodiment, a ramp up circuit responds to a voltage level in a control signal to drive the operating coil and power a DC-to -DC converter and a timing circuit. The invention provides for hot side switching as well as cold side switching of a load.
    Type: Grant
    Filed: August 29, 1988
    Date of Patent: September 25, 1990
    Assignee: Electronic Specialty Corporation
    Inventor: Chester C. Hongel
  • Patent number: 4954924
    Abstract: A switch is mounted in a housing of a high-intensity static magnetic field generator and the housing includes a rotation shaft supported on the housing, a coil mounted relative to rotation shaft, an arm energized by the coil, arm energized by that arm, a rod energized by the arm, a latching/snapping element energized by the rod, a rod moved by the element and a movable electrode plate energized by the rod and movable into and out of engagement with a fixed electrode plate and holding their engaged and disengaged states. Almost every member of the switch is made of non-magnetic material, such as plastics and copper.
    Type: Grant
    Filed: November 16, 1988
    Date of Patent: September 4, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Motoji Haragashira, Yoshimi Maekawa
  • Patent number: 4937703
    Abstract: A relay driver circuit which protects a relay against contact degradation. A detector circuit within the relay driver circuit receives an AC signal at a random phase. The detector circuit correspondingly provides a detector signal to a threshold responsive circuit, such as a timer, which drives the relay. The threshold responsive circuit responds substantially the same to a detector signal provided on a positive cycle and to a detector signal provided on a negative cycle. The relay driver circuit is applied to control a blower fan in an air conditioning system.
    Type: Grant
    Filed: December 12, 1988
    Date of Patent: June 26, 1990
    Assignee: Honeywell Inc.
    Inventor: John T. Adams
  • Patent number: 4930040
    Abstract: A current regulator for an inductive load especially for a coil of an electromagnetic solenoid valve. The current flow through the coil is regulated and compared by means of an operational amplifying nominal current value. The inductive load comparator is initially controlled by a first conductive diode. A second diode having a higher voltage rating than that of the first diode is rendered conductive whenever the nominal current value in an inductive coil decreases rapidly. The current regulator ensures that the magnetic energy in the inductive load remains unchanged when the nominal current value remains constant or changes in small amounts. When a rapid decrease of the coil current occurs, the second diode is rendered conductive.
    Type: Grant
    Filed: November 14, 1988
    Date of Patent: May 29, 1990
    Assignee: WABCO Westinghouse Fahrzeugbremsen GmbH
    Inventors: Jurgen Binarsch, Jurgen Bode, Lutz Danne, Norbert Lissel
  • Patent number: 4920448
    Abstract: An ultra-fast contact breaker is described which includes an ultra-fast cut-off mechanism provided with a repulsion disk fitted with moving contacts (7, 7'), the said mechanism also including fixed contacts (9, 9'), to the input and output terminals (1, 3) of which there is connected an assistance circuit (10) including a capacitor (21) and a coil (23) as well as a group of semiconductors (13, 15, 17, 19), the coil (23) wholly or partly constituting the repulsion coil of the said ultra-fast mechanism, which includes at least two parallel branches (CD, EF), a first branch (CD) including two opposed diodes (13, 15) or similar in series, each directed in the non-conducting direction for the current entering the circuit, a second branch (EF) including two opposed thyristors or similar (17, 19), each directed in the conducting direction for the current entering the circuit, and the LC oscillating circuit (21, 23) which connects the common point of the two diodes (13, 15) or similar and the common point of the two
    Type: Grant
    Filed: January 6, 1988
    Date of Patent: April 24, 1990
    Assignee: Acec Transport S.A.
    Inventor: Henri Bonhomme
  • Patent number: 4905120
    Abstract: A driver circuit for first and second coils includes first and second selector switches coupled in series between first terminals of the coils and a first common junction, first and second diodes coupled in series between second terminals of the first and second coils, respectively, and a second common junction and a source of first potential coupled to the first common junction. A modulation switch is coupled between the second common junction and a source of second potential. The selector switches and modulation switches are operated to cause currents of controlled magnitude to flow through the coils. The circuit has improved fault immunity whereby at least one coil can be energized even when another coil has been subjected to a chassis ground fault.
    Type: Grant
    Filed: October 20, 1988
    Date of Patent: February 27, 1990
    Assignee: Caterpillar Inc.
    Inventors: Conrad G. Grembowicz, Brad Harrell
  • Patent number: 4905121
    Abstract: An operation confirming device for electromagnetic actuator according to the present invention is applied to an electromagnetic actuator comprising a stationary core, a movable core facingly arranged with respect to the stationary core so that the movable core can be moved close to or apart from the stationary core and formed in a closed magnetic circuit together with the stationary core, and an electric coil wound around the closed magnetic circuit. This operation confirming device is provided with a movable core shift detector for detecting time when shift operation of the movable core with respect to the stationary core by applying DC current to the electric coil is completed, by means of transitional fluctuating wave of the applied DC current. This operation confirming device is simply constructed, so that it can be formed in a compact size and a light weight with low manufacturing cost, and the reliability of operation confirming for electromagnetic actuator can be improved.
    Type: Grant
    Filed: May 27, 1987
    Date of Patent: February 27, 1990
    Assignee: Mitsubishi Mining & Cement Co., Ltd.
    Inventors: Tokio Uetsuhara, Kenji Iio
  • Patent number: 4901184
    Abstract: When a voltage (V) of a D.C. power source having an internal resistance (5a) exceeds an "exciting voltage" (FIG. 2), transistors (21, 28 and 33) turn ON, and a transistor (30) turns OFF, and then a tripping winding 16 is excited to close a circuit breaker; on the other hand when the voltage (V) is lowered under a "tripping voltage", the transistor (33) turns OFF and the transistor (30) turns ON, and thereby a load resistor (31) which is less than a resistance 34 of the tripping winding 16 is connected to the D.C. power source; consequently, the voltage V is further lowered by the internal resistance (5a), and a voltage difference is produced between the exciting voltage and the tripping voltage, thus making a "hysteresis characteristic" between the exciting voltage and the tripping voltage.
    Type: Grant
    Filed: August 8, 1988
    Date of Patent: February 13, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazuhiro Ishii, Yoshihiro Hatakeyama, Kazushi Sato, Akira Takao
  • Patent number: 4893212
    Abstract: A power integrated-circuit device is protected against load voltage surges. This is done by providing an alternate current-carrying path that is activated only in response to the occurrence of such surges. This alternate path is independent of and separate from the connection that extends between the device and its power supply source. In addition, circuitry is connected to the device to limit the portion of the surge voltage that can appear across critical elements of the device.
    Type: Grant
    Filed: December 20, 1988
    Date of Patent: January 9, 1990
    Assignee: North American Philips Corp.
    Inventors: Stephen L. Wong, Satyendranath Mukherjee
  • Patent number: 4890183
    Abstract: The invention relates to a device for detecting cutoff and short circuit defects in at least one electrical circuit portion. The detecting device (10) is intended to verify a circuit portion (11) connected to the terminals of a source of direct current (T1) and including a passive element (E, r) interposed between two switch devices (P, Q) comprises on the one hand four differential amplifiers (AD1, AD2, AD3 and AD4) each having one of their inputs connected to the common terminal (F) of the passive element (E, r) and to the first switch device (P) and their other input connected to a reference potential (V3 or V.sub.
    Type: Grant
    Filed: May 2, 1989
    Date of Patent: December 26, 1989
    Assignee: Bull S.A.
    Inventor: Robert Champiau
  • Patent number: 4878147
    Abstract: In an electromagnetic coil drive device an operation coil excites an electromagnet. A switching element is turned on and off by application of a pulse signal thereto and supplies the operation coil with a power supply voltage. A voltage detecting circuit detects the power supply voltage and a gain circuit delivers a closing level signal in accordance with the voltage detected by the voltage detecting circuit. The gain circuit also delivers a holding level signal based on the detected voltage after a predetermined period of time. The level of the holding level signal is higher than that of the closing level signal. A reference wave generating circuit generates a triangular wave. A comparing circuit compares the triangular wave with the closing level signal to thereby generate a closing pulse signal having a predetermined cycle.
    Type: Grant
    Filed: June 28, 1988
    Date of Patent: October 31, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Sakan Oyama, Koji Omori
  • Patent number: 4873606
    Abstract: A safety control device for an actuator of a flap solenoid valve, such as for an automatic transmission. The device includes a current control device which is connected to a shunt resistor for measuring the current through the solenoid valve and the current control device. It also includes a control package which measures the time between the starting of the power to the solenoid valve and the moment when the current reaches a threshold intensity. The control package compares this time with a time range which indicates the proper operation of the solenoid valve so that if the time falls outside this time range, the control package instructs the current control device to cut power to the solenoid valve.
    Type: Grant
    Filed: June 22, 1988
    Date of Patent: October 10, 1989
    Assignee: Regie Nationale des Usines Renault
    Inventor: Gerard Pannier
  • Patent number: 4864457
    Abstract: The invention provides a device for controlling an electromagnet having a coil (L) connected to an AC supply source, through a switch (T) controlled by a control circuit.This control circuit comprising a member for determining the voltage zeros of the AC current (R.sub.4, C.sub.3, D.sub.3, IN.sub.1, C.sub.4, R.sub.6, IN.sub.2), a delay element adjusted for obtaining a delay time which corresponds to the privileged control angle of the electromagnet and a switch-over device (FL) controlled by the delay element for delivering to the switch (T), following a control order, a control signal delayed by said delay time. The invention applies particularly to contactors and electromagnetic valves.
    Type: Grant
    Filed: January 19, 1988
    Date of Patent: September 5, 1989
    Assignee: La Telemecanique Electrique
    Inventors: Bataille Christian, Belbel Elie, Jean-Noel Gast, Lauraire Michel
  • Patent number: 4851952
    Abstract: A switching module having a plurality of switching channels responsive to a microcontroller for coupling electrical power to a load, and decoupling electrical power in the event an undesired operating condition is sensed. Each switching channel includes a switching transistor and transistor driver. Monitoring circuitry senses the actual voltage drop across the load to provide the controller with an indication of undesired operation. A limiting resistor limits the transistor drive such that the transistor is forced out of satuaration during a high power condition, thereby avoiding undesired power dissipation which would otherwise occur if operation in the saturated condition continued.
    Type: Grant
    Filed: April 15, 1988
    Date of Patent: July 25, 1989
    Assignee: Ford Motor Company
    Inventor: Roger J. Cook
  • Patent number: 4833563
    Abstract: An integrated protection unit is a circuit breaker which includes basic overcurrent protection facility along with selective electrical accessories. A molded plastic accessory access cover secured to the integrated protection unti cover protects the accessory components contained within the integrated protection unit cover from the environment. A combined overcurrent trip actuator and multiple accessory module is either field-installed or factory-installed within the integrated protection unit. A separate actuator-accessory module is selected for different combinations of accessory functions.
    Type: Grant
    Filed: April 1, 1988
    Date of Patent: May 23, 1989
    Assignee: General Electric Company
    Inventor: Ronald R. Russell
  • Patent number: 4833565
    Abstract: An electromagnetic contactor or controller is taught in which the voltage which is impressed across the electromagnetic armature winding is controlled with an algorithm to enhance the closing operation. A microprocessor is utilized to implement the algorithm.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: May 23, 1989
    Assignee: Westinghouse Electric Corp.
    Inventors: James A. Bauer, Denis A. Mueller, Robert T. Basnett, Joseph C. Engel
  • Patent number: 4812945
    Abstract: A method for providing a power management for a DC solenoid actuator includes the steps of initially supplying a first number of DC current pulses to the actuator and after a first time interval reducing the number of pulses applied to the solenoid in direct proportion to an output voltage of a source of the DC power. The method further includes the step of changing the duration of the first time period in direct proportion to the output voltage of the source of the DC power.
    Type: Grant
    Filed: May 4, 1987
    Date of Patent: March 14, 1989
    Assignee: Honeywell Inc.
    Inventor: Anthony D'Onofrio
  • Patent number: 4763222
    Abstract: A motor vehicle suspension control includes a solenoid actuator having an actuating coil connected in series with a transistor across an electric power source and circuit protection apparatus for the transistor. The voltage across the transistor is monitored, after a short time delay following turn-on, as a signal indicative of excessive current therethrough. If the signal so indicates, the transistor is turned off for a period of time and then turned on again for another try. This continues for a predetermined maximum number of attempts. Specific clocked digital circuitry is disclosed for controlling the operation and producing the different required time delays or counts.
    Type: Grant
    Filed: April 13, 1987
    Date of Patent: August 9, 1988
    Assignee: General Motors Corporation
    Inventors: Bruce A. Heaston, Jeff A. Foust
  • Patent number: 4757420
    Abstract: A motor controller system is taught in which an overload relay board utilizes a current monitor which produces an output signal which is related to the current being sensed thereby over a wide range of currents which may vary for instance between 1 and 1,000 amperes. This indicative signal is converted to a DC voltage level which is then provided to the analog-to-digital portion of a microprocessor for being converted to a digital number for being processed by the microprocessor for causing the contacts of the motor controller to open at appropriate current values. The system utilizes an integrating capacitor which samples the output current from the sensor 32 times in succession providing a voltage which is proportional to the line current. This voltage which may exceed the input voltage level of the analog-to-digital converter is nevertheless supplied to the analog-to-digital converter and sampled internally by the microprocessor at double the line cycle time period until the 32 samplings have expired.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: July 12, 1988
    Assignee: Westinghouse Electric Corp.
    Inventors: Gary F. Saletta, Joseph C. Engel, John G. Leddy
  • Patent number: 4754362
    Abstract: A magnetically latching switch assembly adapted for use with a motor including first and second serially connected coils wound around a frame to generate oppositely directed magnetic flux through the frame. The coils are arranged so that for the normal run current of the motor, the net magnetic flux is sufficient to magnetically latch the switch against the restoring force of a spring. When the motor is stalled, the increased current is sensed and a portion of the current is diverted from one of the coils to reduce the net magnetic flux and terminate the latching effect. Current sensing and diverting is accomplished by a diode connected across the one coil.
    Type: Grant
    Filed: March 7, 1986
    Date of Patent: June 28, 1988
    Assignee: Eaton Corporation
    Inventor: Wilbert E. Beller
  • Patent number: 4736145
    Abstract: Electric control apparatus (20) for equipment (1) comprising a driving circuit (5) for generating a signal (S.sub.1) to drive the equipment as installed in a vehicle, the driving circuit including circuitry having a first specified working voltage range, and a breaking circuit (6) operatively interposed between the driving circuit and the equipment, the breaking circuit including a first switching circuit (100) for operatively interrupting the supply of the drive signal to the equipment under a condition that the supply voltage (Vdd) is lowered below a first predetermined level (V.sub.
    Type: Grant
    Filed: October 21, 1986
    Date of Patent: April 5, 1988
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Hidetoshi Sakurai, Tomoaki Abe, Shigeo Takemura
  • Patent number: 4731691
    Abstract: A symmetry sensing safety circuit for automatically stopping electrical current flow through a thyristor to an electrical device which is supplied by a source of alternating current electrical energy.
    Type: Grant
    Filed: June 6, 1986
    Date of Patent: March 15, 1988
    Assignee: National Technical Systems
    Inventor: Ned Padwa
  • Patent number: 4707760
    Abstract: A mains protection device for a.c. mains comprises a circuit for detecting whether or not the mains voltage is within an amplitude window. When the voltage goes above or below the window, the mains is disconnected from an appliance and when the voltage returns to within the window for a preset time, the mains is reconnected to the appliance.
    Type: Grant
    Filed: September 27, 1985
    Date of Patent: November 17, 1987
    Assignee: Sollatek Limited
    Inventor: Janan E. Allos
  • Patent number: 4706158
    Abstract: A molded case circuit breaker provides both overcurrent protection as well as accessory protection function by means of a self-contained electronic trip actuator module. Undervoltage release function is provided by a separate undervoltage release assembly that includes the undervoltage coil and an electronic control circuit. Shunt trip facility is provided by the shunt trip coil and a shunt trip control circuitry. The overcurrent, shunt trip and undervoltage release coils are arranged on a magnetic circuit within the electronic actuator module.
    Type: Grant
    Filed: September 24, 1986
    Date of Patent: November 10, 1987
    Assignee: General Electric Company
    Inventors: Frank A. Todaro, John J. Dougherty
  • Patent number: 4702094
    Abstract: A solenoid activated locking system primarily for hood and trunk manual release systems for vehicles. The solenoid is connected to a cable tied to the latch of a conventional hood or trunk release system. Unless activated, the solenoid prevents manual release of the trunk or hood lids to prevent access to the truck or engine compartment to someone who has obtained unauthorized access to the vehicle interior. The solenoid is automatically actuated for a preselected period of time whenever the ignition is turned on or off or when a reset switch is closed for more than a minimum and less than a maximum period of time. In addition, the solenoid is activated automatically during closure of the hood or trunk lid to permit secure engagement of the corresponding latch mechanism. An emergency release cable, hidden in an obscure location external of the vehicle, is provided for enabling manual release of the solenoid in the event of vehicle battery failure or other otherwise disabling event.
    Type: Grant
    Filed: November 27, 1985
    Date of Patent: October 27, 1987
    Assignee: Crimestopper Security Products, Inc.
    Inventor: Larry O. Peterson