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:
Dec. 24, 1996
Filed:
Aug. 15, 1994
Glen D Martinson, Oakville, CA;
Stephen T Makk, Conyers, GA (US);
B.E.L.-Tronics Limited, Mississauga, CA;
Abstract
A low voltage sensing circuit for a battery powered, micro-processor based circuit is provided. A standard voltage regulator has input voltage from a battery, and output voltage which is fed to a system requiring the same, which includes a micro-processor. A voltage divider is connected through a capacitor to an output port of the micro-processor; and the common point of the voltage divider is connected to the base or emitter of a transistor. Periodically, there is an output pulse from the output port of the micro-processor, which pulse has a predetermined length. During the output pulse from the micro-processor, the transistor may become conductive while the capacitor is recharging. Depending of the configuration, the fact that the transistor is conductive is indicative that the input voltage is either below or above a predetermined value. The width of the pulse that is created across a resistor connected to the collector of the transistor and also to an input port of the micro-processor, is indicative of how much below or above the predetermined value the input voltage from the battery has deviated. The predetermined input voltage is established by setting the values of the resistors in the series connected voltage divider.