With Protection Patents (Class 219/668)
  • Patent number: 11831271
    Abstract: A medium voltage inrush current (MVIC) regulator and interconnection control system for interposing between a distributed power generation facility and a utility grid. The facility has a designated generator step-up (GSU) transformer and is connected to the utility grid at a point of interconnect. The system includes a pre-insertion impedance injection transformer, a low voltage first switch connected between the pre-insertion transformer and secondary coils of the designated GSU transformer, a medium voltage second switch connected inline between the pre-insertion transformer and primary coils of the designated GSU transformer, and a controller. In response to restoration of the utility grid following a loss-of-grid event, the controller opens and closes the first and second switches according to an automated pre-energization switching sequence such that magnetic flux in the designated GSU transformer occurs at a reduced rate, thereby reducing inrush of current and undesirable power quality phenomena.
    Type: Grant
    Filed: June 9, 2022
    Date of Patent: November 28, 2023
    Assignee: ADERIS ENERGY, LLC
    Inventors: Adam Will Foodman, Bradley Allan Micallef, Olee Joel Olsen, Jr.
  • Patent number: 11704991
    Abstract: Disclosed is a power failure detection device and method capable of issuing a power failure alert early. The device includes a voltage reduction circuit, a detection voltage generating circuit, a detection circuit, and a transmitting circuit. The voltage reduction circuit is or includes at least one active electronic component, and generates an output voltage according to an input voltage higher than the output voltage. The detection voltage generating circuit is coupled between the voltage reduction circuit and a low voltage terminal, and generates a detection voltage according to the output voltage that is between the output voltage and the voltage of the low voltage terminal. The detection circuit generates a detection result according to the detection voltage and a trigger voltage. The transmitting circuit sends a power failure alert to a far-end device on condition that the detection result indicates that the detection voltage is lower than the trigger voltage.
    Type: Grant
    Filed: May 11, 2021
    Date of Patent: July 18, 2023
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventors: Chia-Lung Wang, Min-Hung Huang, Chien-Yi Li
  • Patent number: 11690142
    Abstract: An induction heating device includes: a working coil, an inverter, a current transformer, a current detecting circuit, a voltage detecting circuit, an AND circuit, and a controller. The induction heating device may detect presence or absence of an object and a material of the object based on a magnitude of resonance current applied to the working coil and a phase difference between the resonance current and a voltage applied to a switching element of the inverter.
    Type: Grant
    Filed: July 21, 2020
    Date of Patent: June 27, 2023
    Assignee: LG Electronics Inc.
    Inventors: Kyung Hoon Jung, Dooyong Oh, Byeong Wook Park
  • Patent number: 9665117
    Abstract: A method to provide high resolution power control in SCR based power supplies utilizing dithering designed to introduce perturbations in the control signal to the power supply controller or firing circuit+, and to thereby control the output of the power supply with increased resolution.
    Type: Grant
    Filed: October 21, 2015
    Date of Patent: May 30, 2017
    Assignee: Warner Power Acquisition, LLC
    Inventor: Souheil Benzerrock
  • Patent number: 9006624
    Abstract: An induction heating system includes an induction heating coil operable to inductively heat a load with a magnetic field, a detector for detecting a current feedback signal corresponding to a current flowing through the induction heating coil, and a controller for detecting a switching transient in the current feedback signal and determining a resonant frequency of the system based on a characteristic of the switching transient.
    Type: Grant
    Filed: July 22, 2010
    Date of Patent: April 14, 2015
    Assignee: General Electric Company
    Inventors: Daniel Brosnan, Mariano Filippa, Kresimir Odorcic
  • Patent number: 8784738
    Abstract: An electrical device for performing a particular function includes a system circuit for performing the function, and a dedicated power supply for providing power to the circuit. Both the system circuit and the power supply are hermetically sealed within a housing. The device within the housing is intended to be sterilized using high temperature, reaching a sterilization temperature. According to the invention, the device includes a thermal switch which is electrically connected between the system circuit and the power supply. With the present invention, the electrical components of a device are automatically protected from thermal damage during sterilization.
    Type: Grant
    Filed: April 30, 2013
    Date of Patent: July 22, 2014
    Assignee: Codman Neuro Sciences Sarl
    Inventors: Benito Valencia Avila, Alec Ginggen
  • Publication number: 20140076876
    Abstract: The invention relates to a method for operating a motor vehicle with a hybrid drive (10), in which at least one operating medium of the motor vehicle is heated to a predefined desired temperature by a dielectric heating device (36, 38). In this way, immediately following a cold start of the motor vehicle, components through which the operating medium flows can be brought particularly rapidly to their optimum operating temperature so that a particularly energy-saving operation of the motor vehicle is possible.
    Type: Application
    Filed: April 26, 2012
    Publication date: March 20, 2014
    Applicant: Audi AG
    Inventor: Jens Papajewski
  • Patent number: 8617472
    Abstract: An electrical device for performing a particular function includes a system circuit for performing the function, and a dedicated power supply for providing power to the circuit. Both the system circuit and the power supply are hermetically sealed within a housing. The device within the housing is intended to be sterilized using high temperature, reaching a sterilization temperature. According to the invention, the device includes a thermal switch which is electrically connected between the system circuit and the power supply. The thermal switch is switchable between an open position wherein the system circuit is electrically isolated from the power supply and receives no power therefrom and a closed position wherein the system circuit is electrically connected to the power supply and receives power therefrom. The thermal switch switches from its closed position to its open position in response to the temperature within the housing rising to a predetermined switch-open temperature value.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: December 31, 2013
    Assignee: Codman Neuro Sciences SARL
    Inventors: Benito Valencia Avila, Alec Ginggen
  • Patent number: 8502123
    Abstract: An apparatus to protect a half or full bridge circuit including a first switching unit and a second switching unit in an image forming apparatus performing induction heating, the apparatus including a switching control unit to control operations of the first switching unit and the second switching unit by generating and outputting a first driving signal to turn on or off the first switching unit and a second driving signal to turn on or off the second switching unit; and an arm-short detecting unit to output a disable signal to stop operation of the switching control unit in response to the first driving signal and the second driving signal simultaneously being signals to turn on the first switching unit and the second switching unit.
    Type: Grant
    Filed: April 22, 2010
    Date of Patent: August 6, 2013
    Assignee: SAMSUNG Electronics Co., Ltd.
    Inventors: An-sik Jeong, Kyung-hwan So
  • Patent number: 8064233
    Abstract: A supplying power adjusting apparatus has excellent temperature response and excellent stabilities to power supply change and load change. The apparatus is provided with a semiconductor inverter for high-speed switching power control, which converts a direct current rectified by a rectifying circuit (10) into alternating current power in response to a control signal and supplies a heater (7) with the power; a temperature change detecting circuit (24) for detecting the temperature change of the heater (7); a power supply change detecting circuit (22) for detecting the power change of the rectifying circuit (10); a load change detecting circuit (23) for detecting the change of the alternating current power supplied to the heater (7); and a power control signal generating circuit (15) which calculates a power quantity to be supplied to the heater (7) and controls the frequency or duty ratio of a control signal to be added to the power controlling semiconductor inverter in response to the calculated results.
    Type: Grant
    Filed: August 12, 2005
    Date of Patent: November 22, 2011
    Assignees: Kokusai Electric Semiconductor Service Inc., Sanko Co., Ltd.
    Inventors: Hideo Ishizu, Masayuki Suzuki
  • Publication number: 20110058826
    Abstract: An apparatus to protect a half or full bridge circuit including a first switching unit and a second switching unit in an image forming apparatus performing induction heating, the apparatus including a switching control unit to control operations of the first switching unit and the second switching unit by generating and outputting a first driving signal to turn on or off the first switching unit and a second driving signal to turn on or off the second switching unit; and an arm-short detecting unit to output a disable signal to stop operation of the switching control unit in response to the first driving signal and the second driving signal simultaneously being signals to turn on the first switching unit and the second switching unit.
    Type: Application
    Filed: April 22, 2010
    Publication date: March 10, 2011
    Applicant: Samsung Electronics Co., Ltd
    Inventors: An-sik JEONG, Kyung-hwan So
  • Patent number: 7825357
    Abstract: This invention provides a power supply which supplies an AC electric current to the coil of a heating unit employing the electromagnetic induced heating method via a connector connecting a plurality of wires, and a method for the power supply. The method includes the steps of supplying electric currents to the coil via 1st and 2nd wires from 1st and 2nd electric current supply units and detecting feedback electric currents via 3rd and 4th wires through the coil. Whether an electric current is abnormally supplied to the coil is monitored on the basis of these detected electric currents. It is controlled in accordance with the monitoring result to stop driving the 1st and 2nd electric current supply units and supply an electric current to the coil.
    Type: Grant
    Filed: July 8, 2009
    Date of Patent: November 2, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Junji Ishikawa
  • Patent number: 7713471
    Abstract: An electrical device for performing a particular function includes a system circuit for performing the function, and a dedicated power supply for providing power to the circuit. Both the system circuit and the power supply are hermetically sealed within a housing. The device within the housing is intended to be sterilized using high temperature, reaching a sterilization temperature. According to the invention, the device includes a thermal switch which is electrically connected between the system circuit and the power supply. The thermal switch is switchable between an open position wherein the system circuit is electrically isolated from the power supply and receives no power therefrom and a closed position wherein the system circuit is electrically connected to the power supply and receives power therefrom. The thermal switch switches from its closed position to its open position in response to the temperature within the housing rising to a predetermined switch-open temperature value.
    Type: Grant
    Filed: October 31, 2005
    Date of Patent: May 11, 2010
    Assignee: Codman Neuro Sciences Sarl
    Inventors: Benito Valencia Avila, Alec Ginggen
  • Patent number: 7624597
    Abstract: Apparatus for making glass fibers has AC induction coils for AC inductive heating of a spinner for spinning molten glass into molten glass fibers, an enclosure that at least partially surrounds the AC induction coils to protect a human worker, and electrically insulating shielding reducing AC power drain by being positioned between the AC induction coils and the enclosure to reduce inductive heating of the enclosure.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: December 1, 2009
    Assignee: CertainTeed Corporation
    Inventor: Michael J. Lembo
  • Patent number: 7573007
    Abstract: This invention provides a power supply which supplies an AC electric current to the coil of a heating unit employing the electromagnetic induced heating method via a connector connecting a plurality of wires, and a method for the power supply. The method includes the steps of supplying electric currents to the coil via 1st and 2nd wires from 1st and 2nd electric current supply units and detecting feedback electric currents via 3rd and 4th wires through the coil. Whether an electric current is abnormally supplied to the coil is monitored on the basis of these detected electric currents. It is controlled in accordance with the monitoring result to stop driving the 1st and 2nd electric current supply units and supply an electric current to the coil.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: August 11, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventor: Junji Ishikawa
  • Patent number: 7339143
    Abstract: The present invention relates to an expansion system using a plasma discharge in which in which a charged electric energy is fast discharged, so that a high pressure is generated within liquid based on an impact wave, which can be used in various industrial fields as a simple expanding method. The expansion system using a plasma discharge comprises a capsule for sealingly storing a certain liquid therein; a cable of which one end is connected with an expansion wire within a liquid of the capsule, and other end is connected to the outside of the capsule; and a controller that converts an external AC power inputted through a terminal into a DC power and indicates the power on a lamp and a voltage meter and applies a high voltage energy to the cable in cooperation with an operation of the push button, wherein an expansion is instantly achieved in the interior of the liquid.
    Type: Grant
    Filed: January 18, 2005
    Date of Patent: March 4, 2008
    Assignee: Swell Tech Co., Ltd.
    Inventor: Yong-So Cho
  • Patent number: 7157674
    Abstract: A detector is operable to detect a displacement of a load by an ascending force based on a period of time from a time a heating output of an inverter drops from a predetermined level to a first level, to a time the heating output returns back to a second level larger than first level. Thereby, the detector distinguishes an intentional removal of the load from the displacement of the load by the ascending force. An induction heater including the detector reduces the displacement of the load by the ascending force and stops the heating of the load when the load is removed intentionally.
    Type: Grant
    Filed: November 18, 2003
    Date of Patent: January 2, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takahiro Miyauchi, Koji Niiyama, Yuji Fujii, Atsushi Fujita, Izuo Hirota
  • Patent number: 7075044
    Abstract: An induction-heating cooking apparatus, operation of which is interrupted by container eccentricity is disclosed. Upon receiving an input signal varying with the degree of eccentricity of a container, the apparatus changes a reference signal for determining the presence or absence of a small load in proportion to a pulse-width control signal controlling the width of an inverter driving pulse. Although the eccentricity of the container occurs in a normal heating operation and completely escapes from a cook zone, the apparatus determines the occurrence of a no-load state, and interrupts an operation of an inverter circuit, resulting in increased stability of a circuit and a product.
    Type: Grant
    Filed: September 7, 2005
    Date of Patent: July 11, 2006
    Assignee: LG Electronics Inc.
    Inventors: Seung Hee Ryu, Eui Sung Kim, Byeong Wook Park
  • Patent number: 7049564
    Abstract: The present invention offers an induction heating apparatus in which the infrared sensor performs stable temperature detection without undergoing the influence of leakage magnetic flux from the induction heating means.
    Type: Grant
    Filed: July 1, 2004
    Date of Patent: May 23, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kiyoyoshi Takada, Naoaki Ishimaru, Tamotsu Izutani
  • Patent number: 7041946
    Abstract: An induction heat treating process with a remote sensor for monitoring the duration of energization of an induction heating coil each time the induction heating coil is consecutively cycled. An identifying tag is preferably attached to, embedded within the induction heating coil or within the surrounding area of the induction coil and transmits a signal to a remote counting sensor that is preferably triggered by and responds to the change in voltage generated as the coil is energized. Alternative means of measuring a cycle may be implemented. The output data from the sensor provides useful information for determining the lifespan of an induction heating coil. Predicting the lifespan of a coil optimizes production by anticipating failure and replacement of a coil during a predetermined down time, limiting on-site inventory, and revolutionizing the billing cycle based on a per cycle cost while decreasing overall production costs and improving inductor coil quality.
    Type: Grant
    Filed: October 26, 2004
    Date of Patent: May 9, 2006
    Inventor: Kathleen M. Bartz
  • Patent number: 7021084
    Abstract: An energy-efficient inductive heater operable to heat a rotary glass fiber discharging spinner. The heater includes shielding disposed between the induction coil and the metal guard plates of the heater. The shielding may comprise any electrically insulative or dielectric material that is capable of withstanding the high operating temperatures occurring in a glass making environment.
    Type: Grant
    Filed: December 9, 2002
    Date of Patent: April 4, 2006
    Assignee: Certainteed Corporation
    Inventor: Michael J. Lembo
  • Patent number: 7019270
    Abstract: A method and apparatus for reducing electrical noise in an electrical signal from a temperature feedback device to an induction heating system. The induction heating system has an electrical connector that is adapted to electrically couple a temperature feedback device to a system controller and to ground via a capacitor circuit. The capacitor circuit shunts electrical noise to ground but allows a temperature signal from the temperature feedback device to be received by the system controller. A shielded extension cable to electrically couple the temperature feedback device to an induction heating system may be used. The shielding of the extension cable is electrically coupled to ground.
    Type: Grant
    Filed: February 23, 2004
    Date of Patent: March 28, 2006
    Assignee: Illinois Tool Works Inc.
    Inventor: Paul D. Verhagen
  • Patent number: 7009159
    Abstract: An induction heating apparatus with high safety is provided in which leakage current is prevented from flowing to the human body and there is no possibility of an electric shock even when an electrostatic shielding member does not sufficiently perform its function. The driving apparatus of the present invention is an induction heating apparatus in which the electrostatic shielding member is provided between an object to be heated and an induction heating coil where sensing portion for sensing the conduction condition of the electrostatic shielding member is provided, and driving portion for driving the induction heating coil is controlled through sensing by the sensing portion.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: March 7, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Akira Kataoka, Izuo Hirota, Katsuyuki Aihara, Nobuyoshi Makio
  • Patent number: 6965098
    Abstract: An induction heat treating process with a sensor for monitoring the duration of energization of an induction heating coil each time the induction heating coil is consecutively cycled. The sensor is preferably a counting mechanism attached to or embedded within the induction heating coil and is preferably triggered by and responds to the change in voltage generated as the coil is energized. Alternative means of measuring a cycle may be implemented. The output data from the sensor provides useful information for determining the lifespan of an induction heating coil. Predicting the lifespan of a coil optimizes production by anticipating failure and replacement of a coil during a predetermined down time, limiting on-site inventory, and revolutionizing the billing cycle based on a per cycle cost while decreasing overall production costs and improving inductor coil quality.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: November 15, 2005
    Inventor: Kathleen M. Bartz
  • Patent number: 6956189
    Abstract: An induction heating system having a fluid cooling unit, a power source, an induction heating device, a controller, and an alarm system to place the system in a safe condition when an improper operating condition is detected. The induction heating system may have a flow switch to detect fluid flow through the system. The system may operate to secure power to the induction heating device when cooling flow is inadequate. Alternatively, the system may increase fluid flow to provide adequate cooling flow. The controller may have a visual indicator of inadequate flow or an improper power source operating condition.
    Type: Grant
    Filed: November 26, 2001
    Date of Patent: October 18, 2005
    Assignee: Illinois Tool Works Inc.
    Inventor: Paul D. Verhagen
  • Patent number: 6861626
    Abstract: An induction heating roller device that keeps leakage current within specifications and prevents the occurrence of erroneous operations caused by common mode noise. The induction heating roller device includes an induction coil, a grounded heating roller magnetically coupled to the induction coil and heated by electro-magnetic induction. A power factor improving capacitor is connected in parallel to and near the induction coil and has a grounded intermediate point. A high-frequency power source biases the induction coil. The leakage current produced by distributed capacitance between the induction coil and the heating roller is returned to the high-frequency power source via the power factor improving capacitor. Thus, the leakage current does not flow out of the induction heating roller device.
    Type: Grant
    Filed: December 11, 2003
    Date of Patent: March 1, 2005
    Assignee: Harison Toshiba Lighting Corp.
    Inventors: Takayuki Ogasawara, Hiroyuki Doi, Ichiro Yokozeki, Manabu Kika, Toshiya Suzuki, Takaaki Tanaka, Syouhei Maeda
  • Patent number: 6815650
    Abstract: An induction heat treating process with a sensor for counting the amount of cycles attributable to an inductor coil. The sensor is preferably a counting mechanism attached to or embedded within the induction coil and is preferably triggered by and responds to the change in voltage generated as the coil is energized. Alternative means of measuring a cycle may be implemented. The output data from the sensor provides useful information for determining the lifespan of an induction coil. Predicting the lifespan of a coil optimizes production by anticipating failure and replacement of a coil during a predetermined down time, limiting on-site inventory, and revolutionizing the billing cycle based on a per cycle cost while decreasing overall production costs and improving inductor coil quality.
    Type: Grant
    Filed: January 2, 2004
    Date of Patent: November 9, 2004
    Inventor: Kathleen M. Bartz
  • Patent number: 6806447
    Abstract: A spatula heating apparatus with excellent usability which overcomes drawbacks inherent to conventional gas burner type and electro-thermal type apparatuses. A spatula heating apparatus for heating spatulas 9, 9a for wax molding includes a heating coil 8 for induction-heating of spatulas 9, 9a, a heating amount setting switch 5, and an inverter control circuit 21 for supplying high frequency current to the heating coil 8 to perform heating at a preset heating amount. When high frequency current is applied to the heating coil 8, the spatulas 9, 9a are heated at the preset heating amount through electromagnetic induction.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: October 19, 2004
    Assignee: Toshiba Home Technology Corporation
    Inventors: Hiroaki Kawaguchi, Osamu Hommura, Yoshinori Watanabe, Yoshio Kato
  • Patent number: 6801443
    Abstract: A method and apparatus for providing welding-type power supply is disclosed. It includes an inverter power circuit, a bus inductor, a snubber circuit a snubber capacitor voltage feedback circuit, and a control circuit. The inverter circuit includes a bus, switches, and an output. The bus inductor is connected to the inverter and the bus. The snubber circuit is connected to the switches. Also, the snubber circuit includes a snubber inductor, a snubber capacitor, a recovery switch connected to the snubber inductor and the snubber capacitor. At least one freewheeling circuit includes the snubber inductor and at least one freewheeling switch. The snubber capacitor voltage feedback circuit is connected to the snubber capacitor and provides a snubber capacitor voltage feedback output to the control circuit. The control circuit includes a comparison circuit that compares the snubber capacitor voltage feedback and a threshold. The output of the comparison controls the recovery switch.
    Type: Grant
    Filed: November 19, 2002
    Date of Patent: October 5, 2004
    Assignee: Illinois Tool Works Inc.
    Inventor: Alan Manthe
  • Patent number: 6713737
    Abstract: A method and apparatus for reducing electrical noise in an electrical signal from a temperature feedback device to an induction heating system. The induction heating system has an electrical connector that is adapted to electrically couple a temperature feedback device to a system controller and to ground via a capacitor circuit. The capacitor circuit shunts electrical noise to ground but allows a temperature signal from the temperature feedback device to be received by the system controller. A shielded extension cable to electrically couple the temperature feedback device to an induction heating system may be used. The shielding of the extension cable is electrically coupled to ground.
    Type: Grant
    Filed: November 26, 2001
    Date of Patent: March 30, 2004
    Assignee: Illinois Tool Works Inc.
    Inventor: Paul D. Verhagen
  • Patent number: 6590190
    Abstract: The invention concerns an induction system for heating, re-heating and keeping warm a food container combining an armature beneath the container, an induction device supporting the container optimised for the safety of the user, the electromagnetic compatibility, and preserving the induction device since the induction is activated only in the presence of an appropriate armature.
    Type: Grant
    Filed: October 19, 2001
    Date of Patent: July 8, 2003
    Assignee: Biotronics S.A.
    Inventor: Jannick Simeray
  • Patent number: 6472748
    Abstract: A system and method for maintaining desired circuit component attributes is shown. According to a preferred embodiment, a high frequency circuit component, such as a MMIC, is retained in a circuit using a degradeable material, such as silver filled epoxy, wherein a portion of the degradeable material remains exposed. A protective coating of resin is applied to the exposed portion of the degradeable material by preferably depositing a predetermined amount of protective material, such as an epoxy resin, a void near the exposed portion of the degradeable material. The protective material preferably migrates to fully cover the exposed portion of the degradeable material without covering the circuit component. Accordingly, the circuit component is protected from substantial changes in operation characteristics due to the protective material and likewise is protected from changes in operation characteristics due to degradation of the degradeable material resulting from exposure.
    Type: Grant
    Filed: March 6, 2000
    Date of Patent: October 29, 2002
    Assignee: Harris Broadband Wireless Access, Inc.
    Inventor: Carl Edward Calvert
  • Patent number: 6359269
    Abstract: A heating device for heating a material to be heated according to a magnetic-induction heating method includes a magnetic-field generator for generating a magnetic field, an electromagnetic-induction heating member for performing electromagnetic-induction heating by the magnetic field generated by the magnetic-field generator, a current detector for detecting a current flowing in the magnetic-field generator, a controller for controlling electric power supplied to the magnetic-field generator based on a result of detection of the current detector, and a current limiter for limiting a maximum current flowing in the magnetic-field generator based on the result of detection of the current detector.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: March 19, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Minoru Hayasaki, Hiroshi Mano
  • Patent number: 5880436
    Abstract: An oven assembly having a housing enclosing a cooking compartment and a blower compartment, and having a blower for circulating air within the cooking compartment, a door mounted to the housing, and a failsafe switch that is capable of deactivating the blower when the door is opened beyond a set point in the range between at least about 10% to 50%.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: March 9, 1999
    Assignee: Garland Commercial Industries, Inc.
    Inventor: Alan Keogh
  • Patent number: 5397878
    Abstract: A power transistor driving circuit for use in an electromagnetic induction heating device comprises an induction coil circuit and a driving circuit. The induction coil circuit is provided with an induction connected with an oscillating circuit made up of capacitances and resistances. The oscillating circuit is provided with at least one power transistor for producing a high frequency switching. The driving circuit comprises at least one quick switching circuit provided with two transistors between which a resistance and an inductance are connected therewith in series. One end of the inductance is connected with the gate of the power transistor for accelerating the reverse current flow of the gate so as to shorten the switching time of the power transistor and to reduce the switching power loss of the power transistor at the time when the power transistor is turned off.
    Type: Grant
    Filed: February 18, 1994
    Date of Patent: March 14, 1995
    Assignee: Superluck Electrics Corp.
    Inventor: Su-Min Chen