David L Perreault

US Patent:

6912142, Jun 28, 2005

Filed:

Oct 22, 2001

Appl. No.:

10/086069

Inventors:

Thomas A. Keim - Boxborough MA, US
David J. Perreault - Brookline MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H02M005/42

US Classification:

363 89

Abstract:

An alternator system having an alternating current (ac) voltage source includes a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system, and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the (ac) voltage source to activate and deactivate the switched-mode rectifier. The controller further includes a PWM generator having a first input to receive a total duty ratio signal synchronized with an angular rotor position of the (ac) voltage source. The switched mode rectifiers are controlled to increase power output levels at lower speeds near idle. The controller combines improved idle speed power output levels with load matching improvements from PWM control for more efficient operation when compared to circuits using conventional control or PWM load matching control alone.

US Patent:

8643347, Feb 4, 2014

Filed:

Jun 4, 2012

Appl. No.:

13/487781

Inventors:

David M. Giuliano - Cambridge MA, US
David J. Perreault - Brookline MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

G05F 1/00

US Classification:

323266, 323271

Abstract:

A converter circuit and related techniques for providing high power density power conversion includes a reconfigurable switched capacitor transformation stage coupled to a magnetic converter (or regulation) stage. The circuits and techniques achieve high performance over a wide input voltage range or a wide output voltage range. The converter can be used, for example, to power logic devices in portable battery operated devices.

US Patent:

20020089866, Jul 11, 2002

Filed:

Oct 22, 2001

Appl. No.:

10/080819

Inventors:

Thomas Keim - Boxborough MA, US
David Perreault - Brookline MA, US

International Classification:

H02M005/42

US Classification:

363/089000

Abstract:

An alternator system having an alternating current (ac) voltage source includes a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system, and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the (ac) voltage source to activate and deactivate the switched-mode rectifier. The controller further includes a PWM generator having a first input to receive a total duty ratio signal synchronized with an angular rotor position of the (ac) voltage source. The switched mode rectifiers are controlled to increase power output levels at lower speeds near idle. The controller combines improved idle speed power output levels with load matching improvements from PWM control for more efficient operation when compared to circuits using conventional control or PWM load matching control alone.

US Patent:

55106986, Apr 23, 1996

Filed:

Aug 5, 1993

Appl. No.:

8/102629

Inventors:

Aleksandar M. Stankovic - Cambridge MA
George C. Verghese - Newton MA
David J. Perreault - Brookline MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

G05F 144

US Classification:

323282

Abstract:

Markov chain controlled random modulation of switching signal sequences of for a power converter. The control is implemented in a power converter having an energy storage device which receives an input power from a source and provides an output power to a load. The converter includes a switching device for coupling the input power source to the energy storage device or coupling the storage device to the load in response to receiving a sequence of control signals generated from a control signal generator. The control signal generator includes a switching signal generator for providing a nominal switching signal sequence which achieves steady state between the input power to the converter and the output power supplied to the load, a modulator for modulating the nominal switching signal sequence with a source of non-deterministic signals to produce a time modulated switching signal sequence, and a control device for controlling the modulator in response to determining the previous modifications performed to the nominal switching signal sequence to maintain a predetermined range of deviation between the time modulated switching signal sequence and the nominal switching signal sequence.

US Patent:

49374141, Jun 26, 1990

Filed:

Sep 12, 1988

Appl. No.:

7/242996

Inventors:

David J. Perreault - Exeter NH
Arun K. Chaudhuri - Florence SC
Roy White - Exeter NH
Richard A. Harris - Hampton Falls NH

International Classification:

B23H 710
B28B 1112

US Classification:

219 6912

Abstract:

A wire guide for EDM machining apparatus comprises a vacuum hot pressed titanium diboride block having a groove on a curved side of the block for positioning EDM wire. The block has a mounting hole therethrough lined with an electrically insulating sleeve.

US Patent:

20220216832, Jul 7, 2022

Filed:

Mar 24, 2022

Appl. No.:

17/703230

Inventors:

- Cambridge MA, US
David J. PERREAULT - Cambridge MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H03F 1/02
H03F 3/24
H03F 1/56
H03F 3/217
H03F 3/193
H03F 3/21
H03F 3/19
H03K 7/08

Abstract:

Described are concepts, systems, circuits and techniques directed toward methods and apparatus for generating one or more pulse width modulated (PWM) waveforms with the ability to dynamically control pulse width and phase with respect to a reference signal.

US Patent:

20230054485, Feb 23, 2023

Filed:

Oct 20, 2022

Appl. No.:

18/048075

Inventors:

- Kyoto, JP
David J. PERREAULT - Cambridge MA, US
Yevgeniy A. TKACHENKO - Belmont MA, US

Assignee:

Murata Manufacturing Co., Ltd. - Kyoto

International Classification:

H03F 1/02
H03F 3/19
H03F 1/32

Abstract:

A power supply modulator circuit includes a multi-output power supply that generates multiple power output signals; at least one power modulator circuit generates a modulated power output signal from the multiple power output signals of the multi-output power supply; at least one pulse shaping network (PSN) having at least one passive element, the PSN configured to shape the modulated power output signal; at least one power amplifier coupled to receive the modulated power signal; and a switching network having a plurality of switches to create or modify power signal paths from the at least one power modulator circuit to the at least one power amplifier.

US Patent:

20230057037, Feb 23, 2023

Filed:

Aug 19, 2022

Appl. No.:

17/820978

Inventors:

- Kyoto, JP
David J. PERREAULT - Cambridge MA, US
Yevgeniy A. TKACHENKO - Belmont MA, US
Aaron COOK - Deerfield NH, US
Kapil KESARWANI - Bedford NH, US

Assignee:

Murata Manufacturing Co., Ltd. - Kyoto

International Classification:

H02M 3/07
H02M 3/158

Abstract:

A circuit configured to receive a first and second voltages and generate an output voltage, the circuit comprising: a first capacitor configured to charge to a voltage equal a difference between the first voltage and the output voltage; a second capacitor configured to charge to a voltage equal to a difference between the first voltage and the second voltage; and a plurality of conductive paths coupled to the first and second capacitors. In a first state, the conductive paths are configured to cause the second capacitor to charge to the voltage equal to the difference between the first voltage and the second voltage. In a second state, the conductive paths are configured to cause the second capacitor to be connected in parallel with the first capacitor to cause the first capacitor to charge to the voltage equal to the difference between the first voltage and the output voltage.