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:
Dec. 22, 1992
Filed:
Sep. 06, 1991
Richard W Roof, Lexington, SC (US);
Other;
Abstract
The motor controller of the present invention includes a power bus, an insulated gate bipolar power transistor and a control circuit. The direct current power bus provided a source and sink of current to be conducted to and from a controller motor. The insulated gate bipolar power transistor selectively conducts transistor current to and from the motor. The control circuit among other things determines power gate timing of the power transistor and the manner in which the insulated gate bipolar transistor conducts and ceases to conduct transistor current to or from the motor. The control circuitry includes a current bias circuit for selectively supplying a turn on voltage and turn off voltage to the power transistor, a slow resistor connects the bias circuit turn off voltage to the power gate of the power transistor to cause the power transistor to slowly cease conducting, a switchable FET for selectively conducting the bias circuit turn off voltage to the power gate through a fast mode circuit which bypasses the slow resistor, and a sensing selection circuit for sensing whether the power transistor is conducting transistor current at a normal level and if the transistor current is normal causing the switchable FET to conduct the turn off voltage and turn off the power gate through the fast mode circuit bypassing the slow resistor.