Abstract: A circuit and apparatus for magnetically sensing fluid flow and applying voltage to a load has a spring loaded check valve disposed within a conduit and provided with a magnetic shield. A magnet is located on one side of the magnetic shield while a sensor, associated with the valve, is located on the opposite side of the magnetic shield. The check valve, and hence the magnetic shield, moves to permit fluid flow. When the magnetic shield moves due to fluid flow, the magnet activates the sensor. A load control circuit includes a supply terminal for receiving a supply voltage and a detector which detects a condition requiring the operation of a load. The detector causes a threshold voltage to be generated from the supply voltage, and a time delay controller controls the time required to generate the threshold voltage.

Abstract: A circuit and apparatus for magnetically sensing fluid flow and applying voltage to a load. A valve disposed within a conduit is provided with a magnetic shield. A magnet is located on one side of the magnetic shield while a sensor, associated with the valve is located on the opposite side of the magnetic shield. The valve, and hence the magnetic shield, moves to permit fluid flow. When the magnetic shield moves due to fluid flow, the magnet activates the sensor. A load control circuit includes a supply terminal for receiving a supply voltage and a detector which detects a condition requiring the operation of a load. The detector causes a threshold voltage to be generated from the supply voltage, and a time delay controller controls the time required to generate the threshold voltage. A DIAC or equivalent element conducts to generate a first trigger signal once the threshold voltage is achieved, and a silicon-controlled rectifier (SCR) generates a second trigger signal in response to the first trigger signal.

Abstract: A circuit and apparatus for magnetically sensing fluid flow and applying voltage to a load has a spring loaded check valve disposed within a conduit and provided with a magnetic shield. A magnet is located on one side of the magnetic shield while a sensor, associated with the valve, is located on the opposite side of the magnetic shield. The check valve, and hence the magnetic shield, moves to permit fluid flow. When the magnetic shield moves due to fluid flow, the magnet activates the sensor. A load control circuit includes a supply terminal for receiving a supply voltage and a detector which detects a condition requiring the operation of a load. The detector causes a threshold voltage to be generated from the supply voltage, and a time delay controller controls the time required to generate the threshold voltage.

Abstract: 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.