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. 05, 1989
Filed:
Jul. 06, 1988
William W Billings, American Township, Allen County, OH (US);
David A Fox, Shawnee Township, Allen County, OH (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A solid state power controller is provided with an output circuit having a transistor which is connected between a pair of output terminals. Base current to the transistor is provided by a drive circuit which includes a pair of series connected diodes that provide biasing to offset the drive circuit and output transistor base voltage drops. Load current is sensed and a DC bias current is supplied to the diode pair, with the DC bias current being proportional to the load current. For bi-directional operation, a second output transistor is connected in series with the first output transistor and a pair of reverse series connected diode are connected in a circuit branch which parallels the two output transistors. Junction points between the output transistors and the reverse series connected diode circuit branch are connected together to provide for bidirectional load current flow.