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:
May. 20, 1997
Filed:
Mar. 21, 1995
Christopher L Watson, Rock Hill, SC (US);
Homelite Inc., Charlotte, NC (US);
Abstract
A method for controlling an AC generator includes a first step of varying the duty cycle of a pulse width modulated signal as a function of an output voltage appearing across at least one output winding so as to increase the duty cycle as the output voltage decreases and to decrease the duty cycle as the output voltage increases. A second step controls the current flow within a rotor winding in accordance with the pulse width modulated signal so as to decrease the current flow when the output voltage increases and to increase the current flow when the output voltage decreases. The method further includes the steps of (a) monitoring a current flow through the at least one output winding so as to detect an unloaded condition and, in response to detecting an unloaded condition, (b) delaying a first predetermined period of time; and (c) initiating an idle condition by slowing the speed of the drive engine. Further in response to detecting an unloaded condition, the method includes the steps of (d) delaying a second predetermined period of time; and (e) automatically decreasing the duty cycle of the pulse width modulated signal so as to decrease the current flow within the rotor winding to thereby decrease the output voltage. Circuitry for accomplishing the method is also described.