Mark A Jacobs

US Patent:

6351396, Feb 26, 2002

Filed:

Mar 4, 2000

Appl. No.:

09/518527

Inventors:

Mark Elliott Jacobs - Dallas TX 75248

International Classification:

H02M 3335

US Classification:

363 216, 363 217

Abstract:

A method and apparatus for dynamically adjusting operation of a converter device to improve conversion efficiency. The converter device includes an inverter and a synchronous rectifier, and is driven by a plurality of drive signals having a duty cycle. The method comprises the steps of: (a) varying timing of a first drive signal a first amount; (b) observing the duty cycle of the conversion device; (c) further varying the first drive signal appropriately to alter the duty cycle toward an extremum; and (d) continuing to operate the converter device with the duty cycle proximate the extremum. In its most preferred embodiment, the method of the present invention includes the further step of: (e) periodically effecting steps (a)-(c) varying a drive signal other than the first drive signal. The comprises: (a) a drive varying means for varying timing of selected individual drive signals of the plurality of drive signals; and (b) a measuring means connected with the drive varying means for measuring the duty cycle. In its most preferred embodiment, the apparatus further comprises: (c) a control means for controlling the drive varying means.

US Patent:

6356461, Mar 12, 2002

Filed:

Jun 8, 2000

Appl. No.:

09/589970

Inventors:

Mark E. Jacobs - Dallas TX 75248

International Classification:

H02M 3335

US Classification:

363 17, 363132

Abstract:

A system and method for estimating magnetic flux in an isolation transformer and a power converter employing the system or the method. The power converter has a full bridge switching circuit coupled across a primary winding of an isolation transformer. In one embodiment, the system includes a conductive path, including an observer, established across at least a portion of the primary winding. A voltage developed by the observer depends upon a value of the magnetic flux in at least the portion of the primary winding.

US Patent:

6377476, Apr 23, 2002

Filed:

Apr 4, 2000

Appl. No.:

09/543022

Inventors:

Simon Fraidlin - Plano TX 75093
Mark Elliott Jacobs - Dallas TX 75248
Allen Frank Rozman - Richardson TX 75082
Vijayan Joseph Thottuvelil - Plano TX 75023

International Classification:

H02M 3335

US Classification:

363 20

Abstract:

An impedance network for passive shoot-through protection of active switches in clamp-mode topologies. In one exemplary embodiment a switch-mode converter, includes: a primary switch; an auxiliary switch coupled in series with a capacitor; and an impedance network, coupled to the primary switch and the auxiliary switch; configured to limit current during simultaneous conduction of the primary and auxiliary switches. The impedance network includes a resistor coupled in series to a diode and both in parallel with an inductor. The impedance network permits the design of a clamp-mode converter without the need for a delay between switch turn-off and turn-on of primary and auxiliary switches.

US Patent:

6396725, May 28, 2002

Filed:

Jul 31, 2000

Appl. No.:

09/638183

Inventors:

Mark E. Jacobs - Dallas TX 75248
Allen F. Rozman - Richardson TX 75082

International Classification:

H02M 7537

US Classification:

363131

Abstract:

A system and method for improving response of a control loop of a power supply. The power supply is configured to drive a load having at least one characteristic associated therewith. In one embodiment, the system includes: (1) a sensing circuit, associated with the power supply, configured to sense the characteristic; and (2) a compensation circuit, coupled to the sensing circuit, configured to adaptively adjust the control loop based on the characteristic to improve the response.

US Patent:

6400580, Jun 4, 2002

Filed:

Oct 10, 2000

Appl. No.:

09/685540

Inventors:

Wayne C. Bowman - Allen TX 75002
Mark E. Jacobs - Dallas TX 75248
Allen F. Rozman - Richardson TX 75082

International Classification:

H02M 3335

US Classification:

363 17, 363 98, 363132

Abstract:

A system and method for reducing a DC magnetic flux bias in a transformer and a power converter employing the system or the method. The power converter has a full bridge switching circuit coupled across a primary winding of a transformer and a hybridge rectifier circuit coupled across a secondary winding of the transformer. The transformer is subject to the DC magnetic flux bias as a result of an imbalance in the hybridge rectifier circuit. In one embodiment, the system includes: (1) a sensor configured to develop a signal representing the DC magnetic flux bias in the transformer; and (2) a controller, coupled to the sensor, configured to operate the full bridge switching circuit as a function of the signal thereby to reduce the DC magnetic flux bias.

US Patent:

6445597, Sep 3, 2002

Filed:

Jun 28, 2001

Appl. No.:

09/894328

Inventors:

Jeffrey J. Boylan - Richardson TX
Mark E. Jacobs - Dallas TX
Li Li - Richardson TX

Assignee:

Tyco Electronics Logistics AG - Steinbach

International Classification:

H02M 3335

US Classification:

363 2106, 363 70, 363 89

Abstract:

A local loop control system and method of operating the same for use with a power converter. The power converter includes a first output coupled to a first synchronous rectifier circuit and a second output coupled to a second synchronous rectifier circuit. The power converter employs a main controller configured to regulate a voltage proportional to a weighted sum of the first and go second outputs. In one embodiment, the local loop control system includes: (1) a first output controller configured to regulate a voltage at the first output and (2) a second output controller configured to regulate a voltage at the second output, one of the first and second output controllers configured to reduce a drive signal to a corresponding one of the first and second synchronous rectifier circuits when a corresponding voltage at one of the first and second outputs exceeds a voltage proportional to the weighted sum.

US Patent:

6606258, Aug 12, 2003

Filed:

Nov 2, 2001

Appl. No.:

10/004420

Inventors:

Mark E. Jacobs - Dallas TX
Thomas G. Wang - Plano TX

Assignee:

Tyco Electronics Power Systems, Inc. - Mesquite TX

International Classification:

H02J 102

US Classification:

363 39

Abstract:

For use with an electronic circuit having first and second reference nodes, a voltage reference translation system and a method of converting signals between the first and second reference nodes are provided. In one embodiment, the voltage reference translation system includes first and second inductors coupled to a common magnetic core and interposed between the first and second reference nodes. Additionally, the voltage reference translation system includes a conversion path coupled through a portion of the common magnetic core configured to substantially convert a signal associated with the first reference node into a signal associated with the second reference node.

US Patent:

6646895, Nov 11, 2003

Filed:

Oct 25, 2001

Appl. No.:

10/057326

Inventors:

Mark E. Jacobs - Dallas TX
Robert J. Murphy, Jr. - Quinlan TX
Ramanujam Ramabhadran - Rowlett TX
Thomas G. Wang - Plano TX
Shashank S. Wekhande - Garland TX

Assignee:

Tyco Electronics Power Systems, Inc. - Mesquite TX

International Classification:

H02M 3335

US Classification:

363 2108

Abstract:

A bias supply circuit and a method of operating a bias supply circuit for use with a switching power supply employing a main switch and an auxiliary switch and having an input voltage and a voltage across a clamp capacitor coupled to a transformer. In one embodiment, the bias supply circuit includes a bias supply winding associated with the transformer and configured to provide a first voltage dependent on at least one of the input voltage and the voltage across the clamp capacitor during a conduction period of the main switch or the auxiliary switch. Additionally, the bias supply circuit further includes a bias supply storage capacitor coupled to the bias supply winding and configured to provide a second voltage dependent on at least another of the input voltage and the voltage across the clamp capacitor during a conduction period of another of the main switch or the auxiliary switch. A sum of the first voltage and the second voltage provides a bias supply voltage.