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:
Apr. 21, 1987
Filed:
Oct. 03, 1980
James H Doyle, Orange, CA (US);
Other;
Abstract
A mass flow controller is disclosed herein having a bridge with a pair of arms positioned in good heat transfer relation with a gas stream, the flow rate of which is to be controlled and energized by a constant current generator wherein a resistance difference due to differential cooling by the gas stream is sensed by a bridge amplifier. A linearization network receives a signal from the bridge amplifier and applies one or more correction factors to the bridge amplifier signal to yield a linearized signal having a substantially linear relation to the rate of flow of the gas stream. A comparator receives the linearized signal and a user selectable set point signal and produces a comparator output signal which is sensed by a servoamplifier. The servoamplifier controls a valve which meters the rate of flow of the gas stream.