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David Bulgher Phones & Addresses

  • 1722 Saddle Dr, Gambrills, MD 21054 (410) 987-8935
  • Ocean City, MD
  • Merry Hill, NC
  • Columbia, MD

Publications

Us Patents

Gate Drive For Wide Bandgap Semiconductor Device

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US Patent:
7782118, Aug 24, 2010
Filed:
Apr 30, 2007
Appl. No.:
11/790973
Inventors:
John Vincent Reichl - Ellicott City MD,
David Everett Bulgher - Gambrills MD,
Ty R. McNutt - Columbia MD,
Assignee:
Northrop Grumman Systems Corporation - Los Angeles CA
International Classification:
H03K 17/687
US Classification:
327427, 327108, 327109, 327110, 327111, 327112
Abstract:
A gate drive circuit for a wide bandgap semiconductor junction gated transistor includes a gate current limit resistor. The gate current limit resistor is coupled to a gate input of the wide bandgap semiconductor junction gated transistor when in use and limits a gate current provided to the gate input of the junction gated transistor. An AC-coupled charging capacitor is also included in the gate drive circuit. The AC-coupled charging capacitor is coupled to the gate input of the wide bandgap semiconductor junction gated transistor when in use and is positioned parallel to the gate current limit resistor. A diode is coupled to the gate current limit resistor and the AC-coupled charging capacitor on one end and an output of a gate drive chip on the other end When in use, the diode lowers a gate voltage output from the gate drive chip applied to the gate input of the wide bandgap semiconductor junction gated transistor through the gate current limit resistor. The gate drive circuitry provides a small, efficient, and cost effective control circuitry for a wide bandgap semiconductor junction gated transistor.

Converter

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US Patent:
H3352, Sep 1, 1987
Filed:
Mar 27, 1987
Appl. No.:
7/032406
Inventors:
Walter E. Milberger - Severna Park MD
Donald C. Lewns - Severna Park MD
David E. Bulgher - Ellicott City MD
Assignee:
The United States of America as respresented by the Secretary of the Army - Washington DC
International Classification:
H02N 3335
US Classification:
363 16
Abstract:
An electrical power converter comprising two current-fed square wave chops the outputs of which are combined and rectified to yield a variable and regulated output voltage. The phase relationship of the choppers are varied to achieve output voltage control and regulation. The chopper outputs are combined in such a way that the choppers never experience the open-circuit inductance of their output transformers. This enhances frequency agility. A novel choke feed system is provided in which the choke flyback energy is absorbed and then transferred to the input of the other chopper.

High-Voltage Milberger Slip Slide Power Conditioner

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US Patent:
4698742, Oct 6, 1987
Filed:
Aug 1, 1986
Appl. No.:
6/891821
Inventors:
Franklin B. Jones - Baltimore MD
Walter E. Milberger - Severna Park MD
David E. Bulgher - Ellicott City MD
Charles S. Kerfoot - Pasadena MD
Assignee:
The United States of America as represented by the Secretary of the Air
Force - Washington DC
International Classification:
H02M 700
US Classification:
363124
Abstract:
A high-voltage converter circuit which uses a slip slide power conditioner to reduce non-monotonic non-linearities in the converter output signal is disclosed. The slip slide power conditioner includes: a choke feed D. C. circulator; two radio frequency (RF) power pumps; a phase detector; a phase controller; and a combiner. The choke feed D. C. circulator receives the D. C. input signal and produces therefrom two voltage output signals which are each sent to one of the two RF power pumps. The two RF power pumps produce two out-of-phase square wave output signals which are algebraically combined in the combiner to form an output signal whose amplitude is a function of phase difference. The phase detector and phase controller sample this output signal and adjust the phase of the two power pumps to remove non-linearities due to secondary ranging (resonance) that beats with harmonics of their square wave signals.
David E Bulgher from Gambrills, MD, age ~64 Get Report