Patent ID: 8476996
Filing Date: 2013-07-02
Classification: H01H

Abstract:
1. A bistable switching method, suitable for a latching relay, the latching relay comprising a rotor shaft, a cylindrical permanent magnet, a first permeability material, a second permeability material, a coil, a hitting device and a contact unit, the cylindrical permanent magnet covering on the rotor shaft as the form of concentric circles, the first permeability material locating in one side of the cylindrical permanent magnet, the second permeability material locating in the opposite side to the first permeability material according to the center of the cylindrical permanent magnet, the coil wrapped around the first permeability material and the second permeability material, the rotor shaft switching the contact unit from an open state or a closed state to other state through the hitting device, the latching relay being open or closed according to the state of the contact unit, the bistable switching method comprising: applying first direction currents to the coil to generate a first force by magnetic fields formed inside and outside of the coil; the first force driving the rotor shaft rotating to drive the contact unit being transferred from an open state to a closed state or keeping the contact unit being in the closed state; turning the first direction currents off, the contact unit still being closed in a stable phase by a second force, wherein the second force is from magnetic attraction between the cylindrical permanent magnet and the first and second permeability materials; applying second direction currents to the coil to generate a third force by magnetic fields formed inside and outside the coiling; the third force driving the rotor shaft rotating to drive the contact unit being transferred from the closed state to the open state or keeping the contact unit being in the open state; and turning the second direction currents off, wherein the contact unit still being open in a stable phase by a fourth force, wherein the fourth force is from magnetic attraction between the cylindrical permanent magnet and the first and second permeability materials.