Patents by Inventor Milan M. Jovanovic

Milan M. Jovanovic has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20090257257
    Abstract: Control device for a switching converter structure comprising at least a first and a second interleaved converter, wherein the control device is configured to designate one converter as master and at least the other converter as slave, to set a time delay of the operating cycle of the slave converter and to synchronize the master and the at the least one slave converter.
    Type: Application
    Filed: April 10, 2008
    Publication date: October 15, 2009
    Applicants: STMicroelectronics S.r.I., Delta Electronics, Inc.
    Inventors: Claudio Adragna, Aldo Novelli, Antonio Borrello, Laszlo Huber, Brian T. Irving, Milan M. Jovanovic
  • Publication number: 20090244944
    Abstract: A power converter system supplies power to one or more loads. The power converter system comprises at least one power converter operating at a desired efficiency; and a power storage system coupled to the at least one power converter for receiving power supplied from the at least one power converter and storing power therein when the at least one power converter operates at an efficiency that is below the desired efficiency.
    Type: Application
    Filed: March 24, 2009
    Publication date: October 1, 2009
    Applicant: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic, Bruce C.H. Cheng
  • Publication number: 20090187925
    Abstract: A light-emitting diode (LED) driver according to the present invention consists of a voltage pre-regulator and multiple linear current regulators with an adaptively-controlled drive voltage. In this LED driver, the efficiency maximization is achieved by eliminating the sensing of the voltage drops across the linear regulators, i.e., by removing the external voltage feedback for the adjustment of the output voltage of the pre-regulator. In the LED driver of the present invention, the self-adjustment of drive voltage is achieved by relying on a relatively strong dependence between the gate-to-source and drain-to-source voltages of a current-regulating transistor, e.g., a MOSFET, operating in the linear region. The driver powers all LEDs in a string with a constant current and provides consistent illumination and optimum operating efficiency at low cost over a wide range of input/output voltage and temperature.
    Type: Application
    Filed: January 17, 2008
    Publication date: July 23, 2009
    Applicant: Delta Electronic Inc.
    Inventors: Yuequan Hu, Milan M. Jovanovic, Colin Weng
  • Publication number: 20090122582
    Abstract: A robust decoder generates an output state from input signals related to the line-voltage signals of a three-phase power system, using a segment identification method based on zero-crossings derived from line-voltage difference signals. The robust decoder includes a basic decoder that provides a current output state based on the input signals, a state table that provides a presumed previous state based on the current output state of the basic decoder, a binary feed back loop including a state element for storing a previous output state, and a selector for providing the output state based on the stored previous output state and the presumed previous state. The robust decoder may be implemented as hardware or software in a digital power converter.
    Type: Application
    Filed: November 8, 2007
    Publication date: May 14, 2009
    Inventors: Zhen Z. Ye, Milan M. Jovanovic
  • Patent number: 7218081
    Abstract: The present invention includes multiple power converters for driving one or more loads via an input power source, AC or DC. A first switching power converter has first one or more windings coupled to an input power source, and a second switching power converter having second one or more windings coupled to one or more loads. A magnetic device comprising a single integrated magnetic core couples the first one or more windings to the second one or more windings for reducing switching loss.
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: May 15, 2007
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Patent number: 6987675
    Abstract: A soft-switched boost converter includes an active snubber to provide soft switching of all semiconductor components. Specifically, the current (“turn-off current”) in the rectifier is switched off at a controlled rate, the main switch is closed under zero-voltage switching (ZVS) condition, and the auxiliary switch in the active snubber is opened under zero-current switching (ZCS) condition. As a result, switching losses are reduced with beneficial effects on conversion efficiency and EMC performance.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: January 17, 2006
    Assignee: Delta Electronics, Inc.
    Inventors: Milan M. Jovanovic, Yungtaek Jang, Yu-ming Chang, Kung-Hui Fang
  • Patent number: 6950319
    Abstract: A single-stage input-current-shaping (S2ICS) flyback converter achieves substantially reduced conduction losses in the primary side of the S2ICS flyback converter by connecting a bypass diode between the positive terminal of a full-bridge rectifier and the positive terminal of an energy-storage capacitor. An effective current interleaving between an energy-storage inductor and the bypass diode is thus obtained in the S2ICS flyback converter around the peak of the rectified line voltage, resulting in a significantly reduced input-current ripple and reduced current stress on the switch. Further, by rearranging the rectifiers in the ICS part of the S2ICS flyback converter in such a way that the energy-storage capacitor and the ICS inductor are connected to the ac line voltage through only two rectifiers, one diode forward-voltage drop is eliminated, which results in a substantially reduced conduction loss in the primary-side rectifiers.
    Type: Grant
    Filed: May 13, 2003
    Date of Patent: September 27, 2005
    Assignee: Delta Electronics, Inc.
    Inventors: Laszlo Huber, Milan M. Jovanovic, Chien-Chung Chang
  • Patent number: 6934167
    Abstract: A contactless electrical energy transmission system includes a transformer having a primary winding that is coupled to a power source through a primary resonant circuit and a secondary winding that is coupled to a load through a secondary resonant circuit. The primary and secondary resonant circuits are inductively coupled to each other. A primary control circuit detects current changes through the primary resonant circuit to control the switching frequency of a controllable switching device for maintaining a substantially constant energy transfer between the primary winding and secondary winding in response to at least one of a power source voltage change and a load change. As a result, excessive circulating energy of the CEET system is minimized providing a tight regulation of the output voltage over the entire load and input voltage ranges without any feedback connection between the primary side and the secondary side.
    Type: Grant
    Filed: May 1, 2003
    Date of Patent: August 23, 2005
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Patent number: 6906930
    Abstract: An isolated boost converter includes first and second switches that are switched simultaneously, a transformer and an energy storage capacitor on the primary side of the transformer for storing energy received from input power source. In one embodiment, when the first and second switches are closed, the energy in the capacitor is transferred to the output load while a boost inductor is charged, and when the first and second switches are open, the boost inductor provides energy from the input voltage source to supply the load and to charge the capacitor, In one embodiment, a third switch is provided to relieve the voltage stress on the secondary side.
    Type: Grant
    Filed: June 26, 2003
    Date of Patent: June 14, 2005
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Publication number: 20040264224
    Abstract: An isolated boost converter includes first and second switches that are switched simultaneously, a transformer and an energy storage capacitor on the primary side of the transformer for storing energy received from input power source. In one embodiment, when the first and second switches are closed, the energy in the capacitor is transferred to the output load while a boost inductor is charged, and when the first and second switches are open, the boost inductor provides energy from the input voltage source to supply the load and to charge the capacitor, In one embodiment, a third switch is provided to relieve the voltage stress on the secondary side.
    Type: Application
    Filed: June 26, 2003
    Publication date: December 30, 2004
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Publication number: 20040252529
    Abstract: A single-stage input-current-shaping (S2ICS) flyback converter achieves substantially reduced conduction losses in the primary side of the S2ICS flyback converter by connecting a bypass diode between the positive terminal of a full-bridge rectifier and the positive terminal of an energy-storage capacitor. An effective current interleaving between an energy-storage inductor and the bypass diode is thus obtained in the S2ICS flyback converter around the peak of the rectified line voltage, resulting in a significantly reduced input-current ripple and reduced current stress on the switch. Further, by rearranging the rectifiers in the ICS part of the S2ICS flyback converter in such a way that the energy-storage capacitor and the ICS inductor are connected to the ac line voltage through only two rectifiers, one diode forward-voltage drop is eliminated, which results in a substantially reduced conduction loss in the primary-side rectifiers.
    Type: Application
    Filed: May 13, 2003
    Publication date: December 16, 2004
    Inventors: Laszlo Huber, Milan M. Jovanovic, Chien-Chung Chang
  • Publication number: 20040218406
    Abstract: A contactless electrical energy transmission system includes a transformer having a primary winding that is coupled to a power source through a primary resonant circuit and a secondary winding that is coupled to a load through a secondary resonant circuit. The primary and secondary resonant circuits are inductively coupled to each other. A primary control circuit detects current changes through the primary resonant circuit to control the switching frequency of a controllable switching device for maintaining a substantially constant energy transfer between the primary winding and secondary winding in response to at least one of a power source voltage change and a load change. As a result, excessive circulating energy of the CEET system is minimized providing a tight regulation of the output voltage over the entire load and input voltage ranges without any feedback connection between the primary side and the secondary side.
    Type: Application
    Filed: May 1, 2003
    Publication date: November 4, 2004
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Patent number: 6504497
    Abstract: The stored energy in the energy-storage capacitors of a power supply during the hold-up time is improved by providing two groups of energy storage capacitors, and by connecting one group of capacitors to the input of a hold-up-time extension circuit that has its output connected to the other group of energy-storage capacitors. Each group of energy-storage capacitors may consist of a single capacitor, or a number of capacitors connected in parallel. The hold-up-time extension circuit is designed so that its output is regulated at a voltage that is lower than the minimum regulation voltage of the output-stage dc/dc converter. As a result, the hold-up-time extension circuit is inactive during the normal operation mode. i.e., when the input voltage is present. In fact, during the normal operation mode both groups of capacitors are effectively connected in parallel so that their voltages are equal.
    Type: Grant
    Filed: May 16, 2001
    Date of Patent: January 7, 2003
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Publication number: 20020071300
    Abstract: The stored energy in the energy-storage capacitors of a power supply during the hold-up time is improved by providing two groups of energy storage capacitors, and by connecting one group of capacitors to the input of a hold-up-time extension circuit that has its output connected to the other group of energy-storage capacitors. Each group of energy-storage capacitors may consist of a single capacitor, or a number of capacitors connected in parallel. The hold-up-time extension circuit is designed so that its output is regulated at a voltage that is lower than the minimum regulation voltage of the output-stage dc/dc converter. As a result, the hold-up-time extension circuit is inactive during the normal operation mode. i.e., when the input voltage is present. In fact, during the normal operation mode both groups of capacitors are effectively connected in parallel so that their voltages are equal.
    Type: Application
    Filed: May 16, 2001
    Publication date: June 13, 2002
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Patent number: 6392902
    Abstract: A soft-switched full-bridge pulse-width modulated (“FB PWM”) converter includes a coupled inductor provides ZVS conditions over a wide range of input voltages and output loads. Further, the FB PWM converter of the present invention requires neither a large leakage inductance in the transformer, nor an external inductor, to achieve ZVS.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: May 21, 2002
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Publication number: 20020044461
    Abstract: A family of soft-switched, full-bridge pulse-width-modulated (FB PWM) converters provides zero-voltage-switching (ZVS) conditions for the turn-on of the bridge switches over a wide range of input voltage and output load. The FB PWM converters of this family achieve ZVS with the minimum duty cycle loss and circulating current, which optimizes the conversion efficiency. The ZVS of the primary switches is achieved by employing two magnetic components whose volt-second products change in the opposite directions with a change in phase shift between the two bridge legs. One magnetic component always operates as a transformer, where the other magnetic component can either be a coupled inductor, or uncoupled (single-winding) inductor. The transformer is used to provide isolated output(s), whereas the inductor is used to store the energy for ZVS.
    Type: Application
    Filed: February 5, 2001
    Publication date: April 18, 2002
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Patent number: 6356462
    Abstract: A family of soft-switched, full-bridge pulse-width-modulated (FB PWM) converters provides zero-voltage-switching (ZVS) conditions for the turn-on of the bridge switches over a wide range of input voltage and output load. The FB PWM converters of this family achieve ZVS with the minimum duty cycle loss and circulating current, which optimizes the conversion efficiency. The ZVS of the primary switches is achieved by employing two magnetic components whose volt-second products change in the opposite directions with a change in phase shift between the two bridge legs. One magnetic component always operates as a transformer, where the other magnetic component can either be a coupled inductor, or uncoupled (single-winding) inductor. The transformer is used to provide isolated output(s), whereas the inductor is used to store the energy for ZVS.
    Type: Grant
    Filed: February 5, 2001
    Date of Patent: March 12, 2002
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Patent number: 6353547
    Abstract: Three-level, constant-frequency, soft-switched isolated converters provide zero-voltage-switching (ZVS) conditions for the turn-on of all primary switches over a wide range of input voltage and output load. These converters achieve ZVS with the minimum duty cycle loss and circulating current, which optimizes the conversion efficiency. The ZVS of the primary switches is achieved by the energy stored in an inductor on the primary side of the isolation transformer. The inductor and transformer are arranged so that a change in the phase shift between the outer and inner pair of switches of the series connection of four switches changes the volt-second product on the windings of the transformer and the windings of the inductor in opposite directions. In some embodiments the primary-side inductor is coupled inductor with two windings, whereas in the other embodiments the inductor has only one winding.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: March 5, 2002
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Patent number: 6246599
    Abstract: A constant frequency, DC/AC inverters that employs a coupled inductor to achieve ZVS in a wide range of load current and input voltage with a reduced circulating energy. In the circuits of the invention, the two windings of the coupled inductors are connected in series and their common terminal is connected to one end of the primary winding of the isolation transformer, which has the other end of the primary winding connected to ground. Each of the other two terminals of the coupled inductors is coupled to the midpoint of the corresponding bridge leg through a series connection of the resonant inductor and a resonant or blocking capacitor. For non-isolated inverter implementations, the common terminal of the coupled inductor is connected directly to the load. The output voltage regulation in the inverters is achieved by a constant-frequency phase shifted control.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: June 12, 2001
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic
  • Patent number: 6239584
    Abstract: A two-switch, two-inductor boost converter achieves output-voltage regulation in a wide input-voltage and load-current range using a constant-frequency by employing an auxiliary transformer to couple current paths of the two boost inductors so that both inductors carry the same current. By forcing the current through the boost inductors to be the same, the energy in both inductors is forced to change in unison, i.e., both inductors increase the energy when both switches are turned on simultaneously and decrease (transfer) energy when either of the converter's two switches is turned off. As a result, the stored and transferred energy of both inductors can be controlled in a wide input-voltage and load range using a constant-frequency control by controlling the time duration that the two switches are simultaneously on.
    Type: Grant
    Filed: June 20, 2000
    Date of Patent: May 29, 2001
    Assignee: Delta Electronics, Inc.
    Inventors: Yungtaek Jang, Milan M. Jovanovic