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:
Sep. 01, 1987
Filed:
Oct. 11, 1985
Applicant:
Inventors:
Kenneth A Baumgartner, Peoria, IL (US);
William Pickering, University Heights, OH (US);
Assignee:
Caterpillar Industrial Inc., Mentor, OH (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05B / ; H02H / ;
U.S. Cl.
CPC ...
318331 ; 318333 ; 318341 ; 361 92 ; 361101 ; 361 33 ;
Abstract
Motor control circuits having solid-state switching elements are commonly used on industrial vehicles such as lift trucks. A short circuit condition in the motor circuit can cause catastrophic failure of the semiconductor switching element. The instant invention detects such a short circuit condition and modifies the motor control signals supplied by a chopper circuit to a switching element. The apparatus includes a trigger circuit for receiving the motor control signals and sensing a voltage across the motor produced in response to electrical power delivered from a power supply.