Peter H Shen

US Patent:

50685767, Nov 26, 1991

Filed:

Aug 13, 1990

Appl. No.:

7/565711

Inventors:

Feng-Kang Hu - Torrance CA
Chung M. Lau - Torrance CA
Kevin Yang - Torrance CA
Joshau S. Zhu - Torrance CA
Peter S. Shen - Rancho Palos Verdes CA
Thomas C. Jednacz - Gastonia NC

Assignee:

Electronic Ballast Technology, Inc. - Torrance CA

International Classification:

G05F 100
H05B 4136

US Classification:

315291

Abstract:

A dimming ballast system wherein the light output of the lamp is controlled by a remote source. The ballast output voltage is regulated by a voltage control feedback loop, the dimming function being achieved by varying the set point of the control loop. The remote control signal, coded by interrupting the current flow to the ballast for a short period, is processed digitally by a microcomputer which generates information to vary the control set point. Circuit means are provided to control the filament voltage of the fluorescent lamps such that as the lamps are dimmed down, the filament voltage is maintained or slightly increased, thus prolonging lamp life and stabilizing the lamp light output.

US Patent:

43565654, Oct 26, 1982

Filed:

Nov 26, 1979

Appl. No.:

6/097286

Inventors:

Peter I. Shen - San Pedro CA

Assignee:

Hughes Aircraft Company - Culver City CA

International Classification:

H01S 303

US Classification:

372 61

Abstract:

A laser beam flow tube arrangement is disclosed in which the Ranque-Hilsch effect is advantageously utilized to reduce thermal blooming in a laser beam. The arrangement includes a tubular member through which the laser beam is propagated longitudinally and a vortical flow generator in gas flow communication with the interior of the tubular member. The flow generator produces vortical flow of a gas having low absorption properties at the wavelength of the laser beam and introduces the vortically flowing gas into the tubular member. The gas flows along a helical path within the tubular member with a tangential velocity selected to provide a negative temperature gradient between the wall and axis of the tubular member which is substantially equal in magnitude to the positive temperature gradient therebetween due to the thermal blooming.

US Patent:

51071843, Apr 21, 1992

Filed:

Aug 13, 1990

Appl. No.:

7/565688

Inventors:

Feng-Kang Hu - Torrance CA
Chung M. Lau - Torrance CA
Kevin Yang - Torrance CA
Joshua S. Zhu - Torrance CA
Peter S. Shen - Rancho Palos Verdes CA
Thomas C. Jednacz - Gastonia NC

Assignee:

Electronic Ballast Technology, Inc. - Torrance CA

International Classification:

H05B 4136

US Classification:

315291

Abstract:

A dimming ballast system wherein the light output of the lamp is controlled by a remote source. The ballast output voltage is regulated by a voltage control feedback loop, the dimming function being achieved by varying the set point of the control loop. The remote control signal, coded by interrupting the current flow to the ballast for a short period, is processed digitally by a microcomputer which generates information to vary the control set point. Circuit means are provided to control the filament voltage of the fluorescent lamps such that as the lamps are dimmed down, the filament voltage is maintained or slightly increased, thus prolonging lamp life and stabilizing the lamp light output.

US Patent:

42075424, Jun 10, 1980

Filed:

Apr 20, 1978

Appl. No.:

5/898049

Inventors:

Peter I. Shen - Torrance CA

Assignee:

The United States of America as represented by the Secretary of the Air
Force - Washington DC

International Classification:

H01S 300

US Classification:

331 945G

Abstract:

A multiple shock aerodynamic window for use within a laser system. The aerodynamic window provides separation between the pressure within the laser cavity and the ambient pressure adjacent thereto. Making up the aerodynamic window is an entrance duct and a capture duct situated transverse to a laser beam output passageway leading from the laser cavity. A wedge-shaped element is located in the entrance duct, partially protruding into the passageway. A diffuser vane is located in the capture duct. Upon the passing of a supersonic flow of gas through the entrance duct at least two shock waves are generated at the wedge-shaped element and cross the passageway. The diffuser vane intersects at least one of the shock waves thereby substantially reducing flow separation in the capture duct. In addition, the entrance wall of the capture duct may be inclined at an angle of approximately 16. degree. in order to assist the diffuser vane in the reduction of flow separation in the capture duct.

US Patent:

50557467, Oct 8, 1991

Filed:

Aug 13, 1990

Appl. No.:

7/565689

Inventors:

Feng-Kang Hu - Torrance CA
Chung M. Lau - Torrance CA
Kevin Yang - Torrance CA
Joshua S. Zhu - Torrance CA
Peter S. Shen - Rancho Palos Verdes CA
Thomas C. Jednacz - Gastonia NC

Assignee:

Electronic Ballast Technology, Incorporated - Torrance CA

International Classification:

H05B 4136

US Classification:

315291

Abstract:

A dimming ballast system wherein the light output of the lamp is controlled by a remote source. The ballast output voltage is regulated by a voltage control feedback loop, the dimming function being achieved by varying the set point of the control loop. The remote control signal, coded by interrupting the current flow to the ballast for a short period, is processed digitally by a microcomputer which generates information to vary the control set point. Circuit means are provided to control the filament voltage of the fluorescent lamps such that as the lamps are dimmed down, the filament voltage is maintained or slightly increased, thus prolonging lamp life and stabilizing the lamp light output.