Patrick Michael Keegan

US Patent:

20070262734, Nov 15, 2007

Filed:

Jul 22, 2004

Appl. No.:

10/565662

Inventors:

Rama Venkat - Aurora IL, US
Patrick Keegan - La Grange Park IL, US
Ernesto Mendoza - Elgin IL, US

International Classification:

H05B 41/295

US Classification:

315360000

Abstract:

The invention provides a filament cutout circuit for a fluorescent lamp (). The filament cutout circuit includes a filament transformer () with a primary winding () and at least one secondary winding (), and a cutout transistor () serially connected to the primary winding (). The secondary winding () provides a filament voltage to a filament () in the fluorescent lamp (). A filament control input () turns on the cutout transistor () for a predetermined time period to preheat the filament ().

US Patent:

57898669, Aug 4, 1998

Filed:

Jul 11, 1997

Appl. No.:

8/893741

Inventors:

William L. Keith - Algonquin IL
Patrick J. Keegan - Schaumburg IL
Bruce R. Rhodes - Inverness IL

Assignee:

Energy Savings, Inc. - Schaumburg IL

International Classification:

H05B 3700

US Classification:

315105

Abstract:

An electronic ballast includes a series resonant inductor and capacitor and a filament winding magnetically coupled to said inductor. The filament winding forms a closed circuit with a filament in a gas discharge lamp, wherein the current induced in the winding opposes a portion of the current through the inductor to reduce the net voltage on the filament during normal lamp operation. In accordance with another aspect of the invention, the filament winding is reversely wound with the inductor on a common core to reverse the phase of the current induced in the filament winding from the current through the inductor.

US Patent:

60231327, Feb 8, 2000

Filed:

Oct 12, 1998

Appl. No.:

9/170144

Inventors:

Kent E. Crouse - Hanover Park IL
Peter W. Shackle - Arlington Heights IL
Patrick J. Keegan - Schaumburg IL
Ronald J. Bezdon - Antioch IL

Assignee:

Energy Savings, Inc. - Schaumburg IL

International Classification:

H05B 3702

US Classification:

315307

Abstract:

An ballast includes a variable frequency boost circuit and a driven half-bridge inverter having a series resonant, direct coupled, parallel output. A control circuit includes a variable frequency driver section, a multivibrator section, and a sensing section. The variable frequency driver changes frequency smoothly, i. e. without discontinuities. The multivibrator section acts as a switch that is enabled or disabled by the sensing section for controlling the frequency of the inverter. Lamp current is required for continued operation of the control circuit. The multivibrator section controls starting by causing the inverter to produce an output signal having a trapezoidal envelope. In the event of an arc, the control circuit quenches the arc and the multivibrator periodically pulses the lamp to attempt to re-start the lamp.

US Patent:

59259906, Jul 20, 1999

Filed:

Dec 19, 1997

Appl. No.:

8/995278

Inventors:

Kent E. Crouse - Schaumburg IL
Ronald J. Bezdon - Schaumburg IL
Michael W. Bandel - Elk Grove Village IL
Patrick J. Keegan - Schaumburg IL
Boyko Boykov - Schaumburg IL
Peter W. Shackle - Arlington Heights IL
William L. Keith - Algonquin IL

Assignee:

Energy Savings, Inc. - Schaumburg IL

International Classification:

G05F 100

US Classification:

315307

Abstract:

An electronic ballast includes an AC to DC converter for power factor correction, a bulk capacitor for storing energy from the converter, and a microprocessor controlled, half-bridge inverter including a series resonant, direct coupled output. Input ports of the microprocessor are coupled to several locations within the ballast to monitor the operation of the ballast or the operation of a gas discharge lamp coupled to the ballast. An analog voltage limiter overrides the microprocessor to limit output voltage under fault conditions. A storage capacitor, connected in series with the bulk capacitor, stores energy at low voltage for powering the microprocessor. The microprocessor is programmed to provide lamp protection features, lumen maintenance, and a warm-up period for a lamp. The microprocessor is also programmed to meet the operating requirements of world markets and of different lamp types.

US Patent:

59363576, Aug 10, 1999

Filed:

Jul 24, 1998

Appl. No.:

9/122231

Inventors:

Kent E. Crouse - Schaumburg IL
Patrick J. Keegan - Schaumburg IL
Ronald J. Bezdon - Schaumburg IL

Assignee:

Energy Savings, Inc. - Schaumburg IL

International Classification:

H05B 3702

US Classification:

315247

Abstract:

A microprocessor controlled, electronic ballast operates a lamp at nominal settings and shifts the operation of the ballast away from nominal settings to reduce interference. The shift is randomized by a test--flip--�shift! routine that prevents all ballasts from attempting the same correction at the same time. On DC input voltage, the frequency of the boost controller is varied to reduce EMI. The ballast operates in bands according to the input voltage. Some bands correspond to full brightness, some to a fixed amount of dimming, and some to a variable amount of dimming. In the event of an abrupt change in load, the microprocessor changes the frequency of the inverter, thereby reducing output power and gradually unloading the boost circuit and maintaining power to the microprocessor.

US Patent:

59821132, Nov 9, 1999

Filed:

Jun 20, 1997

Appl. No.:

8/879181

Inventors:

Kent E. Crouse - Hanover Park IL
Peter W. Shackle - Arlington Heights IL
Patrick J. Keegan - Schaumburg IL
Ronald J. Bezdon - Antioch IL

Assignee:

Energy Savings, Inc. - Schaumburg IL

International Classification:

H05B 3702

US Classification:

315291

Abstract:

An instant start ballast includes a variable frequency boost circuit and a driven half-bridge inverter having a series resonant, direct coupled, parallel output. A control circuit includes a variable frequency driver section, a multivibrator section, and a sensing section. The variable frequency driver changes frequency smoothly, i. e. without discontinuities. The multivibrator section acts as a switch that is enabled or disabled by the sensing section for controlling the frequency of the inverter. Lamp current is required for continued operation of the control circuit. The multivibrator section controls starting by causing the inverter to produce an output signal having a trapezoidal envelope. In the event of an arc, the control circuit quenches the arc and the multivibrator periodically pulses the lamp to attempt to re-start the lamp.

Author:

Patrick Keegan

ISBN #:

0131876201

Author:

Patrick Keegan

ISBN #:

0132395525

Author:

Patrick Keegan

ISBN #:

0851396038