AH49FQ Hall Effect Sensor Diodes Incorporated AH49FQ Hall Effect Sensor is a small and versatile linear hall effect sensor operated by the magnetic field from a permanent magnet or an electromagnet. This sensor integrates low noise output circuitry that eliminates the need for external filtering components. The supply voltage sets the AH49FQ sensor's output voltage and varies in proportion to the strength of the magnetic field. This sensor includes precision resistors to provide increased temperature stability and accuracy. The AH49FQ hall effect sensor is used in position sensing, liquid level sensing, weight sensing, ferrous metal detectors, rotary encoders, magnetic code reading, and current sensing.