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:
Oct. 15, 1996
Filed:
Nov. 02, 1994
Larry G Ball, Snow Camp, NC (US);
Patrick C Koehl, Fort Wayne, IN (US);
General Electric Company, Fort Wayne, IN (US);
Abstract
A method and apparatus for preventing overspeed of an electrically powered golf car having a shunt wound direct current electric motor with an armature winding and a field winding serially connected to respective switching devices and to a source of on-board direct current electric power. The golf car includes a control adapted and connected to regulate the current in each of the armature and field windings for controlling speed in response to an operator's command. The golf car incorporates overspeed detection by sensing the magnitude of current in each of the armature winding and the field winding and detecting when the current in the armature winding reverses direction. The magnitude of the armature winding current upon such reversal is compared to a preselected value and an overspeed signal generated when the reverse current magnitude exceeds the preselected value. The field current is then controlled, in response to the overspeed signal, to limit the speed of the golf car to inhibit the overspeed condition. Additionally, the voltage at the motor armature winding is monitored during a time period when the motor is in a non-energized condition and a motion signal indicative of motor armature rotation is provided upon detection of a motor armature winding voltage. The motor field winding is energized, in response to the motion signal, with a voltage of a polarity for generating a field current to cause the motor to act as an electric current generator and the current generated by the motor armature is circulated through a plugging diode and into the motor armature for electrically retarding rotation of the motor armature by plug braking.