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:
Oct. 10, 2006
Filed:
Oct. 14, 2005
Kenneth J. Burdick, Skaneateles, NY (US);
Kenneth J. Burdick, Skaneateles, NY (US);
Welch Allyn, Inc., Skaneateles Falls, NY (US);
Abstract
An improved two loop capacitive sensor oscillator circuit converts a transducer capacitance to a frequency and includes a first loop to create an oscillatory waveform having a frequency related to a capacitance of the capacitive transducer. The first loop includes a resistor. The resistor is electrically coupled to a capacitor. The resistor is also electrically coupled to the capacitive transducer. The capacitive transducer is electrically coupled to an input of a first inverter gate. A second loop oscillates at the frequency of the first loop and further generates a second waveform of a substantially square wave shape at the same frequency. The second loop is electrically coupled to the first loop and the output of a third inverter gate is substantially a square wave at the frequency related to the capacitance of the capacitive transducer.