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:
May. 28, 1991
Filed:
Mar. 31, 1989
Henry J Zylstra, Alburnett, IA (US);
Steven J Flock, Cedar Rapids, IA (US);
Square D Company, Palatine, IL (US);
Abstract
A voltage-to-frequency converter is provided for generating a frequency which is proportional to the square of the input voltage provided to the converter. Since the input voltage is correlative to current flowing in a conductor, the output frequency exhibits a proportionality similar to the relationship between the temperature of the conductor and the current flowing in it. The arrangement includes two charging circuits which receive the input voltage and are alternately charged as a function of the input voltage. While the first charging circuit charges to a predetermined voltage, the second charging circuit discharges. Upon exceeding the predetermined voltage, the output of a flip flop is set to discharge the first charging circuit, and to charge the second charging circuit. When the second charging circuit charges to a predetermined voltage, the output of the flip flop is reset, so that the first charging circuit charges again. As the input voltage rises, the charging time for each circuit decreases, thus causing the output of the flip flop to switch at a higher frequency. In effect, the frequency of the output of the flip flop changes at a rate proportional to the square of the input voltage.