David C Petruska

US Patent:

6738239, May 18, 2004

Filed:

Feb 26, 2001

Appl. No.:

09/795045

Inventors:

David C. Petruska - Fort Collins CO

Assignee:

Woodward Governor Company - Fort Collins CO

International Classification:

H02H 504

US Classification:

361 23, 361 30

Abstract:

A novel motor driver with an active snubber circuit. The motor driver is interposed between an external electrical power source and an electrical motor. The electrical motor is driven in first and second states such that the electrical motor produces an inductive flyback current when it switches torque direction. The motor driver comprises a reverse voltage protector in series between the power source and the electrical motor allowing flow of electrical power to the motor; and a capacitor arranged in parallel circuit with the motor between the motor and the diode (or other reverse voltage protector). The active snubber circuit is in parallel circuit with the motor between the diode and the electrical motor. The active snubber circuit comprises a switch having a sensor responsive to increases in the bus voltage resulting from the inductive flyback current and a resistor in series with the switch regulating electrical current flow.

US Patent:

8276564, Oct 2, 2012

Filed:

Aug 18, 2009

Appl. No.:

12/542794

Inventors:

David C. Petruska - Fort Collins CO, US

Assignee:

Woodward, Inc. - Fort Collins CO

International Classification:

F02P 5/00
F23Q 3/00

US Classification:

12340612, 123605, 361263

Abstract:

A multiplexing drive circuit for an AC ignition system having a common leg that includes two switches coupled in series, and one or more dedicated legs, wherein each leg includes two switches coupled in series. The multiplexing drive circuit also includes a transformer for each of the one or more dedicated legs, each transformer having a primary winding coupled between one of the one or more dedicated legs and the common leg, and wherein each transformer has a secondary winding coupled in parallel to a spark plug, and a pulse-width modulated (PWM) switch controller configured to operate the common leg and dedicated leg switches to control characteristics of the spark discharge for the spark plug.

US Patent:

8461844, Jun 11, 2013

Filed:

Oct 1, 2010

Appl. No.:

12/896370

Inventors:

David C. Petruska - Fort Collins CO, US

Assignee:

Woodward, Inc. - Fort Collins CO

International Classification:

F02P 17/00

US Classification:

324399, 324393, 324402, 324459, 324464, 73 3508, 7311408, 7311462

Abstract:

A self charging ion current sensing circuit is provided. The self charging ion current sensing circuit is coupled to spark generation circuitry, and utilizes the spark plug electrodes as the ion current sensing electrodes. The self charging is achieved by utilizing the spark current during an ignition event to charge an ion bias capacitor. After the ignition event, the charge voltage build up on the ion bias capacitor is used to provide an ion current across the spark plug gap. The ion current is passed through an offset stage that translates the ion current sense voltage to a voltage that can be buffered and amplified from a single power source available in automotive and vehicular applications. The output of the circuit provides tri-state information, including spark current, null current, and linear representation of ion sense current.

US Patent:

20020118497, Aug 29, 2002

Filed:

Feb 13, 2002

Appl. No.:

10/074864

Inventors:

David Petruska - Fort Collins CO, US

Assignee:

Woodward Governor Company - Fort Collins CO

International Classification:

H02H005/04

US Classification:

361/023000

Abstract:

A reverse voltage protector for a motor drive is presented. The circuit is in series with an external electrical power source and the motor drive or electrical motor. The reverse voltage protector comprises a switch having a zener diode to protect the switch from overvoltage and a resistor regulating electrical current flow in the control terminal of the switch.

US Patent:

20040000878, Jan 1, 2004

Filed:

Jun 28, 2002

Appl. No.:

10/185765

Inventors:

David Petruska - Fort Collins CO, US
Jeffrey Barrett - Bolton MA, US
Mark Woolston - Bolton MA, US

Assignee:

Woodward Governor Company

International Classification:

H05B037/02

US Classification:

315/2090CD, 315/276000

Abstract:

An ignition system for an engine includes an exciter circuit for use with an igniter, the exciter circuit having a step-up transformer the utilizes a relatively low voltage in its primary to produce a high voltage pulse that is applied to the igniter to create ionization and breakdown. The system also utilizes a low voltage high energy circuit to provide high current energy to the igniter after initial breakdown and during the plasma arc phase. The high energy circuit is decoupled from the step-up transformer so that high current is conducted through a bypass diode rather than through the transformer.

US Patent:

20110255208, Oct 20, 2011

Filed:

Jul 1, 2011

Appl. No.:

13/175311

Inventors:

David C. Petruska - Fort Collins CO, US
Doyle Kent Stewart - LaPorte CO, US
Monte Lee Wegner - Bellvue CO, US
Gerald Michael Eberhardt - Fort Collins CO, US

Assignee:

WOODWARD, INC. - Fort Collins CO

International Classification:

F23Q 3/00

US Classification:

361263

Abstract:

A multiplexing drive circuit for an AC ignition system having a common leg that includes two switches coupled in series, and one or more dedicated legs, wherein each leg includes two switches coupled in series. The multiplexing drive circuit also includes a transformer for each of the one or more dedicated legs, each transformer having a primary winding coupled between one of the one or more dedicated legs and the common leg, and wherein each transformer has a secondary winding coupled in parallel to a spark plug, and a pulse-width modulated (PWM) switch controller configured to operate the common leg and dedicated leg switches to control characteristics of the spark discharge for the spark plug. Wherein the switch controller is capable of real time diagnostic checks by monitoring the time at which a spark discharge event takes place.

US Patent:

20120125287, May 24, 2012

Filed:

Jan 10, 2012

Appl. No.:

13/347448

Inventors:

Domenico Chiera - Fort Collins CO, US
David C. Petruska - Fort Collins CO, US
Gregory James Hampson - Boulder CO, US

Assignee:

Woodward, Inc. - Fort Collins CO

International Classification:

F02B 19/12
F02B 19/16

US Classification:

123254, 123266

Abstract:

A pre-chamber spark plug that includes a shell. Additionally, the pre-chamber spark plug includes an insulator disposed within the shell. In a particular embodiment, a center electrode has a first portion surrounded by the insulator, and a second portion that extends from the insulator into a pre-chamber. The pre-chamber defined by the shell. In a further embodiment, a ground electrode is attached to the insulator. In particular embodiments, the ground electrode is tubular in shape and includes an inner spark surface ring spaced in surrounding relation to the center electrode to create a spark gap, an outer ring attached to the shell, and a plurality of rounded spokes connecting the inner and outer rings. In a particular embodiment, the ground and center electrodes accommodate attachment of precious metal alloys to increase electrode surface life. In another embodiment the ground electrode and insulator is coaxial to the center electrode.

US Patent:

20170044970, Feb 16, 2017

Filed:

Oct 24, 2016

Appl. No.:

15/332718

Inventors:

- Fort Collins CO, US
David C. Petruska - Fort Collins CO, US
Gregory James Hampson - Boulder CO, US

International Classification:

F02B 19/12
F02P 13/00
F02P 23/04
F02P 15/00
F02P 21/02

Abstract:

A pre-chamber spark plug that includes a shell. Additionally, the pre-chamber spark plug includes an insulator disposed within the shell. In a particular embodiment, a center electrode has a first portion surrounded by the insulator, and a second portion that extends from the insulator into a pre-chamber. The pre-chamber defined by the shell. In a further embodiment, a ground electrode is attached to the insulator. In particular embodiments, the ground electrode is tubular in shape and includes an inner spark surface ring spaced in surrounding relation to the center electrode to create a spark gap, an outer ring attached to the shell, and a plurality of rounded spokes connecting the inner and outer rings. In a particular embodiment, the ground and center electrodes accommodate attachment of precious metal alloys to increase electrode surface life. In another embodiment the ground electrode and insulator is coaxial to the center electrode.