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. 07, 1981
Filed:
May. 16, 1977
David T Cavil, Menomonee Falls, WI (US);
William R Krueger, Hartford, WI (US);
Outboard Marine Corporation, Waukegan, IL (US);
Abstract
Disclosed herein is a control for a direct current motor including a field weakening solenoid switch including a solenoid coil, which control includes an electronic switch connected in series with the coil for selectively connecting the coil to a source of direct current, and a device adapted for providing an electronic digital signal having a frequency proportional to motor speed. The control also includes a first electronic comparator adapted for receiving the digital signal and for providing an output cut-in signal for operating the electronic switch so as to connect the solenoid coil to the source of direct current to effect field weakening when the motor speed increases to a predetermined field weakening cut-in speed, and a second electronic comparator adapted for receiving the digital signal and for providing an output cut-out signal for operating the electronic switch to disconnect the coil from the source of direct current so as to prevent field weakening when the motor speed increases to a predetermined field weakening cut-out speed greater than the predetermined field weakening cut-in speed.