Encoder Using Magnet Drop Out Feature For Theft Detection

Abstract

An encoder to be mounted to a shaft extending from a piston meter configured to compute a volume of distributed fluid includes a magnet affixed to the shaft via a floating magnet holder, a magnetic sensor configured to sense the flux density and direction of a magnetic field created by the magnet and to output a signal indicating the flux density and direction of the magnetic field to a printed circuit board, and the printed circuit board configured to output a signal indicating the volume of distributed fluid if the encoder has not been tampered with and configured to output an error signal if the encoder has been tampered with.

Description

[0001] related application [0002] This application claims priority to Provisional Patent Application Serial No. 61 / 289,756, entitled "Encoder Using Magnet Dropout Feature to Detect Theft," filed December 23, 2009, and Provisional Patent Application Serial No. 61 / 291,506, entitled "Encoder Using Magnet Dropout Feature to Detect Theft," and U.S. Patent Application Serial No. 12 / 952,496, filed November 23, 2010, entitled "Using Magnet Encoders that Drop Out Feature Detect Theft", the subject matter of which is incorporated herein by reference in its entirety. technical field [0003] The present invention relates generally to fluid dispensing systems and, in particular, to encoders for measuring the output of fluid dispensing systems. Background technique [0004] Fluid dispensing systems typically utilize encoders to measure the amount of fluid dispensed. These encoders are often paired with a fluid metering device, for example, the shaft of a piston flow meter, and are us...

AI Technical Summary

Problems solved by technology

However, this venting results in the continual presence of fuel vapor around the encoder, which limits the options for viable designs

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