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. 22, 1993
Filed:
May. 03, 1991
Eduardo M Molieri, Mesa, AZ (US);
Susan D Stephens, Chandler, AZ (US);
Andrew W Hardell, Seguin, TX (US);
David L Barron, Scottsdale, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A low-power dual voltage drive circuit and method which includes controlling a stepper motor overdriven with a high voltage. The stepper motor drive circuit includes a high voltage supply for overdriving the stepper motor, a low voltage supply, and an overdrive switch mechanism connected between the high voltage supply means and the stepper motor input. The method includes repetitively triggering the overdrive switch in response to a control signal, overdriving the stepper motor with the high voltage, producing an overdrive current, sensing the overdrive current, producing an additional control signal when the overdrive current reaches a preset value, switching off the overdrive current in response to the second control signal, resetting the overdrive switch to enable the overdrive switch to again receive the first control signal, and driving the stepper motor with a nominal low voltage.