The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 08, 2008
Filed:
Jun. 15, 2004
Theodore S. Wilmot, Fort Collins, CO (US);
Richard S. Brzostek, Rockford, IL (US);
John C. Driscoll, Raleigh, NC (US);
Theodore S. Wilmot, Fort Collins, CO (US);
Richard S. Brzostek, Rockford, IL (US);
John C. Driscoll, Raleigh, NC (US);
Woodward Governor Company, Fort Collins, CO (US);
Abstract
A turbine engine ignition exciter circuit applies energy stored in the exciter tank capacitor to the load (igniter plug) through a thyristor type semiconductor switching device that minimizes leakage current at elevated operating temperatures. The semiconductor switching device is periodically activated by a trigger circuit to initiate discharge of energy stored in exciter tank capacitor to mating ignition lead and igniter plug. The circuit operates at a modest, for example, approximately 1.8 kV, tank circuit voltage to further reduce switching device leakage current related stresses at elevated temperatures allowing relatively long capacitor charge cycles, increased upper operating temperature capability and improved reliability. The circuit uses a low side switch circuit topology for releasing energy from said capacitor to ground whereby negative polarity energy is applied to the exciter.