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. 31, 1989
Filed:
Jun. 10, 1988
John P Schulte, Eden Prairie, MN (US);
Kelly M Orth, Apple Valley, MN (US);
Roger L Frick, Chanhassen, MN (US);
Brian L Westfield, Eden Prairie, MN (US);
Randy K Paschke, Chaska, MN (US);
Rosemount Inc., Eden Prairie, MN (US);
Abstract
A charge balanced feedback type transmitter generates charge packets representative of a sensed parameter. Improved performance is achieved by the additiion of resistance connected between a charge packet generating reactance and an integrator to reduce the effects of noise caused by switching transients and by ground noise which is coupled to the charge packet generating circuitry by stray capacitance. The charge packets are integrated by the integrater, and the integrator output is supplied from a selective basis to the input of a comparator. The output of the comparator is used to control the application of charge packets to the integrator to achieve charge balance. The input of the comparator is selectively connected to the output of the integrator, to a first supply voltage, or to a second supply voltage to ensure a stable output of the comparator at a critical time when charge is being supplied to the integrator.