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:
Jul. 12, 1988
Filed:
Feb. 19, 1987
Gary F Saletta, Penn Township, Westmoreland County, PA (US);
Joseph C Engel, Monroeville Boro, PA (US);
John G Leddy, Brookline, MA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A motor controller system is taught in which an overload relay board utilizes a current monitor which produces an output signal which is related to the current being sensed thereby over a wide range of currents which may vary for instance between 1 and 1,000 amperes. This indicative signal is converted to a DC voltage level which is then provided to the analog-to-digital portion of a microprocessor for being converted to a digital number for being processed by the microprocessor for causing the contacts of the motor controller to open at appropriate current values. The system utilizes an integrating capacitor which samples the output current from the sensor 32 times in succession providing a voltage which is proportional to the line current. This voltage which may exceed the input voltage level of the analog-to-digital converter is nevertheless supplied to the analog-to-digital converter and sampled internally by the microprocessor at double the line cycle time period until the 32 samplings have expired. If at any time during this doubled sampling process the output of the analog-to-digital converter digitally saturates, the left shifting technique is provided with other memory locations within the microprocessor to provide an approximate double value of voltage so that at the end of the 32 line half cycles a very close approximation of the actual current is contained within storage locations within the microprocessor for effective utilization thereby.