Circuit and apparatus for sensing fluid flow

摘要

A circuit and apparatus for magnetically sensing fluid flow through a conduit. The circuit includes a sensor and a sensor magnet for biasing the sensor in an on condition. A second magnet indicative of the relative position of a conduit valve substantially neutralizes the sensor magnet when the valve is closed to prevent fluid flow, and does not substantially neutralize the sensor magnet when the valve is open to permit fluid flow. The sensor can be a Hall effect sensor, and the sensing of fluid flow causes an indication current to flow. Circuitry is provided to apply a voltage to a load in response to the indication current.