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:
Jun. 16, 1987
Filed:
Jan. 31, 1985
David J Shero, South Park Township, Allegheny County, PA (US);
Habib Dadpey, Atlanta, GA (US);
C Scott Magee, Houston, TX (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
An arrangement of interconnected timers is provided for operation with a microprocessor programmed to determine time delay counts that are fed out to these timers such that the timers can take care of the actual task of firing GTO inverter switches or not firing GTO inverter switches coupled with an AC traction motor for a vehicle. It is necessary to have correct transitions between the minus GTO switch and the plus GTO switch being ON for providing the desired motor voltage conditions with minimum electromagnetic interference in relation to the power supply. In addition the use of timer queues in complicated synthesis modes like the PWM and the quasi six-step operates to give the microprocessor adequate operating time for reasonable control signal time duration calculations. The timers are synchronized in hardware by a single crystal frequency, and they are synchronized in software such that the three phase independent waveforms stay 120.degree. apart.