Abstract: A heat sink includes a first surface including an attachment area to which a semiconductor module is attached and is installed such that a first side of the first surface extends in a vertical direction. Thermal grease containing oil is applied to the attachment area. A first groove extending in a horizontal direction is formed below the attachment area in the first surface. An inner wall of the first groove includes a groove top surface and a groove bottom surface spaced below the groove top surface. The length of the first groove in the horizontal direction is shorter than the length of the first surface in the horizontal direction. A wall includes a first wall extending in the horizontal direction and second walls respectively connected to both end portions of the first wall in the horizontal direction and inclined upward as the second walls extend away from the first wall.

Abstract: A system for metal detection comprises a single aperture comprising two or more sets of detection coils that surround the perimeter of the aperture. A flow path of materials passes through the aperture. Each set of detection coils comprises a transmitter and two receiver coils, with the transmitter coil located between the two receiver coils. Each set of detection coils is at a different angle relative to the flow path.

Abstract: A bidirectional switch switched to conduct and interrupt a bidirectional current between a pair of input terminals. An input device receives a dimming level representing a value of light output of the load. A controller controls the bidirectional switch according to the dimming level. The controller controls the bidirectional switch to keep the bidirectional switch in an off-state from a start point of a half cycle of the AC voltage of the AC power supply to a first time point when a first time period therefrom elapses, and to turn the bidirectional switch to an on-state at the first time point. The controller turns the bidirectional switch to the off-state at a second time point when a second time period elapses from the first time point. The controller keeps the bidirectional switch in the off-state from the second time point to an end point of the half cycle.

Abstract: An exemplary embodiment is disclosed of a relay turn-off control system for use with an alternating-current (AC) signal input. The system may include a relay, a relay current load sensor connected to the relay, and a rectifier circuit connected to the relay current load sensor and having an output. A microprocessor may be connected to the rectifier circuit output. The microprocessor may be configured to set a relay turn-off signal output time based on an empirically determined duration time for the relay to turn-off and further based on determining a zero-cross period via use of a modulo operation.

Abstract: A magnetic field sensor with a magnet is disposed proximate to a ferromagnetic target object having at least one ferromagnetic surface. The magnetic field sensor is operable to sense a relative location between the magnetic field sensor and the ferromagnetic target object along a movement line. In some embodiments, the target object is also spinning about a rotation axis parallel to the movement line. A corresponding method is described.

Abstract: A load control device may control power delivered to an electrical load from an AC power source. The load control device may include a controllably conductive device adapted to be coupled in series electrical connection between the AC power source and the electrical load, a zero-cross detect circuit configured to generate a zero-cross signal representative of the zero-crossings of an AC voltage. The zero-cross signal may be characterized by pulses occurring in time with the zero-crossings of the AC voltage. The load control device may include a control circuit operatively coupled to the controllably conductive device and the zero cross detect circuit. The control circuit may be configured to identify a rising-edge time and a falling-edge time of one of the pulses of the zero-cross signal, and may control a conductive state of the controllably conductive device based on the rising-edge time and the falling-edge time of the pulse.

Abstract: The invention relates to a method of controlling switchgear in order to estimate the remanent flux value of a power transformer during disconnection from a high-voltage electrical network using voltage measurements delivered by a capacitive voltage transformer by correcting the transfer function of the capacitive voltage transformer, and in which said value is delivered to a controller that determines the optimum switchgear switching instant.

Abstract: Some embodiments include a system to control when electricity is provided to an inductive load. Other embodiments of related systems and methods are also disclosed.

Abstract: An input circuit includes an interface structured to output a logic signal from an alternating current signal of a pair of elongated conductors. A load is switchable to the elongated conductors. A processor outputs a control signal to switch the load to the elongated conductors asynchronously with respect to the alternating current signal for a first predetermined time, inputs the logic signal, determines if the input logic signal is active a plurality of times during the first predetermined time and responsively sets a first state of the alternating current signal, and, otherwise, sets an opposite second state of the alternating current signal, and delays for a second predetermined time, which is longer than the first predetermined time, for the opposite second state before repeating the output, and, otherwise, delays for a third predetermined time, which is longer than the second predetermined time, for the first state before repeating the output.

Abstract: A target-closing phase-map generating section generates in advance a target closing phase map in consideration of a pre-arc characteristic and variations of a mechanical action of a breaker, and amplitude fluctuations of the load voltage. A target-closing time calculating section calculates a target closing time string from frequencies and phases of the power source voltage and the load voltage, respectively, of the breaker referring to the target closing phase map. A closing control section, when a close command 11 is inputted, controls the timing of outputting a closing control signal based on a predicted closing time and the target closing time string.

Abstract: A signal analyzer for calculating the power consumption and power factor of a three-phase power system driving a motor includes logic that determines whether the analyzer's own input terminals are wired in a proper or inverted manner. To do this, the signal analyzer observes a pattern of zero crossing slope values of the three line-to-line voltages of the three-phase power system and observes a pattern of zero crossing slope values of the current in the three power lines. The analyzer also compares the slope of a voltage signal as the signal passes through zero volts and the sign of a corresponding current signal that exists as the voltage signal crosses zero volts. Based on the observed voltage and current patterns and the voltage-to-current relationships, the analyzer can positively identify which of a plurality of inputs or signal wires are inverted.

Abstract: A method and an apparatus for optimizing switching operations executed by a switching device coupled to an AC power line, wherein signals related to the waveform of the electrical phases of the power line are acquired. When a command for executing a switching operation on one of the electrical phases is issued, the signals acquired are stored. Based on the signals stored, data indicative of the severity of switching transients occurred during the executed switching operation and second data indicative of the time occurred for the executed switching operation are calculated and correlated to each other. Based on the data calculated, it is determined whether a parameter representative of a target point on the waveform for executing future switching operations substantially synchronous with the waveform has to be adjusted.

Abstract: A heat dissipation apparatus includes a metal enclosure for an electronic device, at least one heat pipe secured to the enclosure, a fin assembly secured to the enclosure, a centrifugal blower secured to the enclosure for promoting heat dissipation for the fin assembly. The heat pipe has an evaporating section thermally connecting with a heat generating electronic component within the enclosure, and first and second condensing sections respectively connecting with the enclosure and the fin assembly. The enclosure absorbs and dissipates heat generated by the heat generating electronic component. The heat dissipation surface area is increased and as a result the heat dissipation efficiency of the heat dissipation apparatus is improved.

Abstract: The present invention relates to a multi-pulse HVDC system which is capable of minimizing the number of thyristors by providing a thyristor auxiliary circuit in a conventional 12-pulse thyristor HVDC(High Voltage Direct Current), not using an additional stack of a thyristor and which is implemented based on an auxiliary circuit having a multi-pulse thyristor HVDC system like 24-pulse/36-pulse/48-pulse converters. The multi-pulse HVDC system is characterized in that an upper side thyristor converter 12 and a lower side thyristor converter 13 are installed in a ?-?-Y transformer 11, and two current smoothing reactor 39 and a direct voltage dividing condenser 38 are installed between the upper side thyristor converter 12 and the lower side thyristor converter 13, and two thyristors 32, 33: T2 and T1 are connected to one double winding transformer 31.

Abstract: The present invention relates to a multi-pulse HVDC system which is capable of minimizing the number of thyristors by providing a thyristor auxiliary circuit in a conventional 12-pulse thyristor HVDC(High Voltage Direct Current), not using an additional stack of a thyristor and which is implemented based on an auxiliary circuit having a multi-pulse thyristor HVDC system like 24-pulse/36-pulse/48-pulse converters. The multi-pulse HVDC system is characterized in that an upper side thyristor converter 12 and a lower side thyristor converter 13 are installed in a &Dgr;-&Dgr;-Y transformer 11, and two current smoothing reactor 39 and a direct voltage dividing condenser 38 are installed between the upper side thyristor converter 12 and the lower side thyristor converter 13, and two thyristors 32, 33: T2 and T1 are connected to one double winding transformer 31.

Abstract: The relay obtains three-phase current signals from two power line sources thereof, typically two independent feeder lines. The two sets of signals are processed by a single processing means, which independently controls the circuit breakers associated with each feeder line, depending on the values of current obtained.

Abstract: An improved method for controlling a power relay of a microwave oven which is capable of reducing the generation of sparking which occurs when the contact points of the power relay are separated, by turning off the power relay at a time (2n-1) .pi.+3/4.pi.during the "+" cycle and at a time 2n.pi.+3/4.pi. during the "-" cycle in the voltage phase or the current phase, for separating the contact points when the flow of the current is decreased, thus extending the life span of the relay. The method includes judging whether the power relay was previously turned off during the "+" cycle of the power voltage or during the "-" cycle of the power voltage when a clock signal of 50 Hz/60 Hz is inputted, and turning off the power relay after an apex of the "+" or "-" cycle of the power voltage after delaying the output time of a relay driving signal for a predetermined time in accordance with the judgement.

Abstract: This invention pertains to sensorless measurement of electromagnetically induced displacement in actuators and similar units. Primarily, the device imposes a constant frequency and amplitude excitation sine wave on a coil through a fixed impedance of a drive isolation network. The amplitude and phase of the voltage across the coil fluctuate depending upon the coil's inductance. This variation in the value of the inductance is dependent upon the change in magnetic flux density generated by the coil current and the displacement in air gap between the coil pole and armature. Accordingly, a measurable magnitude of displacement can be controllably imposed upon a system of solenoids. The displacement is thus measured and set without the use of extrinsic sensors.

Abstract: A magnetic contactor including a phase switch and a phase angle adjusting device for adjusting the phase angle at which the phase switch provides for the supply of voltage to an electromagnet to energize the electromagnet. The phase angle is adjusted, via the phase angle adjusting device, to a position at which a collision velocity of a movable iron core against a fixed iron core of the magnetic contactor is lowered, and where the impact of the movable iron core is reduced to increase the life of the magnetic contactor.

Abstract: Method and apparatus for quickly and easily securing a computer device, such as a floppy disk drive, to a device carrier. In a preferred embodiment, the carrier contains a plurality of dowels that align with pre-existing screw holes on the device. When the device is placed into the carrier, a first dowel attached to a bottom panel of the carrier is inserted into a first screw hole of the device. The device is thereby partially secured to the carrier. The device is further secured to the carrier when both the device and the carrier together are inserted into a computer bay. As the carrier enters the computer bay, a second dowel flexibly attached to a side panel of the carrier is inserted into a second screw hole of the device. Therefore, whenever the device and carrier are in the computer bay, the device is completely secured to the carrier.

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.

Abstract: A phase detecting actuator for a steering system having a rotatable steering shaft and a rotatable output shaft coupled to the steering shaft so that the output shaft is rotatable relative to the steering shaft includes a cylindrical magnet attached to and rotatable with one of the steering shaft and the output shaft of the steering system. An electromagnetic system includes a magnetic coil and first and second cylindrical poles having opposite polarities and communicating with the magnetic coil, the first and second poles attached to and rotatable with the other of the steering shaft and the output shaft of the steering system.

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.

Abstract: A method of operating a relay includes shifting, by a predetermined time increment each time the relay coil is energized, the time in the sine wave of the applied AC power source at which the relay coil is energized. The method further provides for similarly shifting the time in the sine wave at which the relay coil is de-energized. When applied to a system having two relays, the method includes providing such shifting to both relays and further includes providing a predetermined time delay between the time one relay is de-energized and the other relay is energized.

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 when the contacts are closed or opened the contacts are not exposed to an undesired voltage. A feedback control circuit senses the opening and closure of the contacts so that in the event the contacts, for example close at an undesireable point on the load current waveform the microcontroller adjusts for the necessary delay to cause the actuation of the relay to occur such that the contact closure is at the desired point in the load current waveform.

Abstract: A control device and system for an appliance and methods of making the same are provided, the control device having a control unit to energize the coil of a relay with a power source at substantially a desired lead point on the voltage wave cycle thereof so as to tend to cause the contacts of the relay to subsequently close substantially at a certain point on the voltage wave cycle each time a load is to be interconnected to the power source whereby a lag time period exists between the desired lead point and a certain point, the control unit having a sensing unit to sense the lag time by detecting when the coil current of the relay coil decreases momentarily by the contacts initially closing during that particular cycle of operation of the control device, the control unit having a unit to automatically adjust the desired lead point should the sensed lag time on a certain previous cycle of operation not cause the contacts to close substantially at the certain point in order to tend to cause the contacts to clo

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.

Abstract: A driver circuit that is responsive to an input AC voltage provides a variable drive signal to a load circuit, such as, a solenoid coil, for each actuation of a switch where the variable drive signal duration is determined by the setting of a variable resistor. In one embodiment, a sine wave shaper produces a positive edge variably delayed square wave timing signal for a continuously clocked flip-flop. In response to the switch actuation, the clocked flip-flop generates a control signal for a selected period of time that is related to one cycle of the AC input voltage. In another embodiment, a one shot produces a positive edge variable delayed square wave timing signal in response to the switch, the signal then being received by another one shot which creates a control signal for a selected period of time that is related to one cycle of the AC input voltage. The selected period of time occurs only during the positive portion of the input AC voltage cycle.

Abstract: A driver circuit that is responsive to an input AC voltage provides a variable drive signal to a load circuit, such as, a solenoid coil, for each actuation of a switch. A sine wave shaper produces a positive edge variably delayed square wave timing signal for a continuously clocked flip-flop. In response to the switch actuation, the clocked flip-flop generates a control signal for a selected period of time that is related to one cycle of the AC input voltage. The selected period of time occurs only during the positive portion of the input AC voltage cycle. The control signal is employed to generate the drive signal for the load circuit. The driver circuit provides switch bounce rejection equal to one cycle of the AC input voltage.

Abstract: A control device and system for an appliance and methods of making the same are provided, the control device having a control unit to energize the coil of a relay with a power source at substantially a desired lead point on the voltage wave cycle thereof so as to tend to cause the contacts of the relay to subsequently close substantially at a certain point on the voltage wave cycle each time a load is to be interconnected to the power source whereby a lag time period exists between the desired lead point and a certain point, the control unit having a sensing unit to sense the lag time by detecting when the coil current of the relay coil decreases momentarily by the contacts initially closing during that particular cycle of operation of the control device, the control unit having a unit to automatically adjust the desired lead point should the sensed lag time on a certain previous cycle of operation not cause the contacts to close substantially at the certain point in order to tend to cause the contacts to clo

Abstract: A non-volatile memory circuit for use with an E.sup.2 PROM includes redundant, parallel connected, floating node MOSFET memory cells for storing complementary information. The non-volatile memory cells are connected in parallel to a volatile memory circuit via a voltage level shifter circuit for writing operations, and via twin mixed PMOS and NMOS transistors for reading operations. With the combined complementary non-volatile memory cells and the twin mixed pairs of transistors, the stored information is retained in the event that one of the memory cells fails.

Abstract: A driving device for a door lock-actuator includes a door locking switch, a control circuit, a drive device and a counter. This device is free from the malfunctions and the restrictions of detecting limits which are problems in conventional-mechanical one-way switches, and can detect the locking and unlocking action certainly. In this device, the control circuit detects the locking and unlocking direction, and the drive device can drive the door lock-actuator of all the doors adjacent a passenger's seat according to the output signal from the control circuit.

Abstract: A malfunction detector is connected to switches provided in a machine, such as a punch press, for actuation when a malfunction occurs. The detector is capable of supplying an alternating current test signal to the switches and determining whether the resistance of the switches to the test signal is greater than or less than a threshold value. The test signal preferably has a frequency which is equal to mains supply frequency or a harmonic thereof and the malfunction detector preferably only responds to changes of state of the switches during specific time windows.

Abstract: A power relay for a switching control device of a microwave oven, designed to prolong the life of the power relay by alternately carrying out the drive of the power relay used for controlling the power in a microwave oven at the positive (+) cycle and the negative (-) cycle of the alternating current input voltage, respectively. The output signal of the 50 Hz/60 Hz clock generator for generating the clock signal corresponds to the frequency of the alternating current input voltage and is combined with the output signal of the power relay ON/OFF generator. The power relay ON/OFF control part is composed so as to alternately realize the ON-point and the OFF-point of power relay at the positive cycle and the negative cycle of the alternating current input voltage, respectively, so that no potential difference takespace in one direction between contact of the power relay, and the life is thereby prolonged.

Abstract: In a hybrid relay circuit for supplying current to a load with a AC power supply, an electromagnetic relay is provided and the contact thereof is connected in series to the load and the AC power. The electromagnetic relay is driven by a driving circuit in accordance with an input control signal, thereby switching the supply of current to the load.

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.

Abstract: A three-phase rectifier utilizes three feedback controlled ferroresonant regulators to convert a three-phase signal into a regulated DC voltage. A monitoring circuit is included which responds to a signal loss at any input phase to actuate an alarm signal.

Abstract: A relay control circuit is disclosed in which a timer circuit is actuated by a reference clock pulse in synchronism with an AC voltage supplied by a commercial power supply. An output signal of the timer circuit causes current to flow in the coil of the relay thereby to close the contact of a relay. The invention further comprises a polarity-reversing device for reversing the polarity in accordance with the variations in the output signal of the timer circuit. The reference clock pulse is applied to the timer circuit through the polarity-reversing device.

Abstract: An alarm system for warning of unbalance or failure of one or more phases of a multi-phase load circuit which is convenient and practical to use even where the load circuit is drawing a large current and where the flow of power to the load may be controlled by various devices, said alarm system including a three-phase resistance bridge circuit with a phantom neutral point at the common juncture of three similar resistances connected in a Y-pattern and each shunted across a secondary winding of transformers having magnetic cores encircling the power leads to the load circuit and with the outer terminals of these resistors connected through resistance elements to the adjustable taps of three potentiometers included in the respective legs of a second Y pattern having the outer ends of these legs connected to the respective load phases for defining a second neutral point at their common junction.