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. 20, 2004
Filed:
Oct. 15, 1999
Rajesh Nair, Nashua, NH (US);
Roger Holman, Acton, MA (US);
David Gagnon, Brookline, NH (US);
Owen R. Mann, Townsend, MA (US);
Degree Controls, Inc., Milford, NH (US);
Abstract
An air flow sensor including a temperature dependent resistor device, a first circuit and a second circuit. The first circuit applies a voltage to the temperature dependent resistor device until it reaches a first temperature. The first circuit includes a first reference resistance leg, a first variable resistance leg including the temperature dependent resistor device, and a first comparator connected to both legs for determining when the temperature dependent resistor device reaches the first temperature. The second circuit includes a second reference resistance leg, a second variable resistance leg including the temperature dependent resistor device, and a second comparator connected to both legs for determining when the temperature dependent resistor device reaches a second temperature. A processor is connected to both the first and second comparators and programmed to time the period of time it takes the temperature dependent resistor device to change from the first temperature to the second temperature to determine the heat loss rate of the temperature dependent resistor device.