Milan M Jovanovic

Author:

Milan Jovanovic

ISBN #:

8675580797

Author:

Milan Jovanovic

ISBN #:

8675581491

Author:

Milan Jovanovic

ISBN #:

8675582137

Author:

Milan N. Jovanovic

ISBN #:

8674190642

Author:

Milan N. Jovanovic

ISBN #:

8675490704

US Patent:

6353547, Mar 5, 2002

Filed:

Mar 29, 2001

Appl. No.:

09/819699

Inventors:

Yungtaek Jang - Apex NC
Milan M. Jovanovic - Cary NC

Assignee:

Delta Electronics, Inc. - Taipei

International Classification:

H02M 75387

US Classification:

363132, 363 16, 363 17

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.

US Patent:

6356462, Mar 12, 2002

Filed:

Feb 5, 2001

Appl. No.:

09/775636

Inventors:

Yungtaek Jang - Apex NC
Milan M. Jovanovic - Cary NC

Assignee:

Delta Electronics, Inc. - Taipei

International Classification:

H02M 3335

US Classification:

363 17, 363132

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.

US Patent:

6388898, May 14, 2002

Filed:

Jan 22, 2001

Appl. No.:

09/767637

Inventors:

Heng-Chia Fan - Chungli, TW
Ko-Yu Hsiao - Chungli, TW
Milan Jovanovic - Cary NC

Assignee:

Delta Electronics, Inc. - Taipei

International Classification:

H02M 3335

US Classification:

363 20, 363 17, 363 89

Abstract:

A technique, which substantially reduces the number of power-stage and control circuit components in an isolated DC/DC converter with parallel current-doubler rectifier stages, includes on the primary side transformers with serially connected primary windings each having a corresponding secondary winding coupled to one of the voltage-doubler stages. In one embodiment, the primary and secondary windings and filter inductors of the current-doubler rectifier stages are provided on an integrated magnetic core. The filter inductors in each current-doubler rectifier stage can be provided as coupled inductors. In one embodiment, an X-shaped magnetic core is provided to achieve coupled or uncoupled filter inductors.

US Patent:

6392902, May 21, 2002

Filed:

Aug 31, 2000

Appl. No.:

09/652869

Inventors:

Yungtaek Jang - Apex NC
Milan M. Jovanovic - Cary NC

Assignee:

Delta Electronics, Inc. - Neihu

International Classification:

H02M 3335

US Classification:

363 17, 363 5602, 363132

Abstract:

A soft-switched full-bridge pulse-width modulated (âFB PWMâ) 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.

US Patent:

6504497, Jan 7, 2003

Filed:

May 16, 2001

Appl. No.:

09/855715

Inventors:

Yungtaek Jang - Apex NC
Milan M. Jovanovic - Cary NC

Assignee:

Delta Electronics, Inc. - Taiwan

International Classification:

H03M 100

US Classification:

341125, 363 21, 363 39, 363 89

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.

US Patent:

6906930, Jun 14, 2005

Filed:

Jun 26, 2003

Appl. No.:

10/608314

Inventors:

Yungtaek Jang - Apex NC, US
Milan M. Jovanovic - Cary NC, US

Assignee:

Delta Electronics, Inc. - Taipei

International Classification:

H02M003/335

US Classification:

363 17, 363 5602

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.

US Patent:

6934167, Aug 23, 2005

Filed:

May 1, 2003

Appl. No.:

10/426721

Inventors:

Yungtaek Jang - Cary NC, US
Milan M. Jovanovic - Cary NC, US

Assignee:

Delta Electronics, Inc. - Taipei

International Classification:

H02M003/335

US Classification:

363 2102, 363 2103, 363 97

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.

US Patent:

6950319, Sep 27, 2005

Filed:

May 13, 2003

Appl. No.:

10/438265

Inventors:

Laszlo Huber - Cary NC, US
Milan M. Jovanovic - Cary NC, US
Chien-Chung Chang - Taoyuan, TW

Assignee:

Delta Electronics, Inc. - Taipei

International Classification:

H02M003/335
H02H007/122

US Classification:

363 2112, 363 5609

Abstract:

A single-stage input-current-shaping (SICS) flyback converter achieves substantially reduced conduction losses in the primary side of the SICS 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 SICS 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 SICS 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.