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. 11, 1991
Filed:
Oct. 04, 1989
Stanley Wrzesinski, Arlington Heights, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A bridge circuit (2) for driving a load such as an electric motor (36) in one direction or an opposite direction as desired, the circuit comprising first (4) and second (24) parallel arms for connection across an automobile battery supply voltage, each arm comprising an FET switch (6, 26) and a bipolar PNP transistor (8, 28) connected in series via mid-point nodes for connection across the load. In each arm the intrinsic diode of the field effect transistor and the base-emitter junction diode of the PNP transistor are arranged to conduct forward-biased current in opposite directions. In this way, no current path is provided through the arms of the bridge circuit in the event that the voltage supply to the circuit is reversed.