Abstract: A Hall effect sensing apparatus for a moving object includes a moving magnetic member having concave and convex segments alternately at is periphery, a detector including a pair of Hall effect elements for converting a magnetic signal to an electric signal, a processing circuit for processing signals from the detector, a magnet for providing magnetic field to the Hall effect elements, and a yoke provided in close proximity to the magnet. The yoke has a smaller surface area than that of the magnet and is movably arranged so as to adjust detecting sensitivity of the sensing apparatus. Therefore, even though there are some variances of magnetic characteristics in the detector, the detecting sensitivity of the sensing apparatus can be adjusted to an optimum level by observing a signal outputted from the processing circuit.

Abstract: A movable magnet type pump, wherein a magnet moving body having at least one axially magnetized permanent magnet and an axially extending through liquid passage is arranged so as to be slidable inside a liquid introducing chamber; a plurality of coils are fixed so as to enclose the liquid introducing chamber; a first check valve is arranged on a liquid introducing side of the liquid introducing chamber; a second check valve is arranged on a liquid discharge side of the through liquid passage; and the magnet moving body is caused to reciprocate by interaction between current applied to the respective coils and magnetic flux from the magnet moving body cutting across the respective coils.

Abstract: In a moving magnet type actuator, a magnet moving body including at least two permanent magnets of which same poles are confronting each other and an intermediate magnetic substance. The magnet moving body is movably arranged inside at least three coils. The at least three coils are connected so that current flows in different directions with a zone between the permanent magnets as a boundary. Whereby thrust and efficiency of the moving magnet type actuator is improved.