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| Number | Title | Issue Date |
| 7061743 | Multi-pulse HVDC system using auxiliary circuit 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 t... | 06/13/2006 |
| 6927959 | Method for operating an electromagnetic switching device and electromagnetic switching device Switching contacts of a switching device are provided to ensure optimum service life. An optimum switching point, in terms of the load of one of the switching contacts, is determined depending on a current path that is measured during the switching process and the s... | 08/09/2005 |
| 6567256 | Dual protective relay for power systems 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 wit... | 05/20/2003 |
| 5883366 | Method for controlling power relay of microwave oven 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) π+3/4πdur... | 03/16/1999 |
| 5841621 | Sensorless measurement of electromagnetic actuator displacement device 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 dr... | 11/24/1998 |
| 5684668 | Magnetic contactor having phase angle adjuster 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... | 11/04/1997 |
| 5452176 | Electrically operated control device and system for an appliance and method of operating the same 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 ... | 09/19/1995 |
| 5412530 | Phase detecting actuator 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 an... | 05/02/1995 |
| 5347420 | Electrically operated control device and system for an appliance and method of operating the same 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 ... | 09/13/1994 |
| 5329417 | Relay control circuit and method of operating same 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 simila... | 07/12/1994 |
| 5267120 | Relay control apparatus 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. ... | 11/30/1993 |
| 5224014 | Electrically operated control device and system for an appliance and methods of making the same 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 ... | 06/29/1993 |
| 5218509 | Electrically operated control device and system for an appliance and method of operating the same 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 ... | 06/08/1993 |
| 5146388 | Variable power drive circuit 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 res... | 09/08/1992 |
| 5144520 | Power solenoid drive circuit with switch bounce rejection 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... | 09/01/1992 |
| 5138514 | Electrically operated control device and system for an appliance and methods of making the same 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 ... | 08/11/1992 |
| 4858060 | Driving device for door lock-actuator 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... | 08/15/1989 |
| 4837656 | Malfunction detector 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 resi... | 06/06/1989 |
| 4833284 | Power relay switching control device for microwave oven 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... | 05/23/1989 |
| 4767944 | Hybrid relay circuit having electromagnetic relay for switching AC power supply 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... | 08/30/1988 |
| 4745515 | Electrically operated control device and system for an appliance and method of operating the same 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 ... | 05/17/1988 |
| 4159514 | Signal loss detector for three phase circuit 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... | 06/26/1979 |
| 4153922 | Relay control circuit 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 r... | 05/08/1979 |
| 4053876 | Alarm system for warning of unbalance or failure of one or more phases of a multi-phase high-current load 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 controll... | 10/11/1977 |
