Patent ID: 6057750
Filing Date: 2000-05-02
Classification: H01F

Abstract:
A magnet device with double fixing positions for changing a magnetic circuit comprising:an external housing whose inner edge is fitted with a coil, whereby an inside of said external housing includes a space for axial movement of an iron core at different positions, and a portion of a main body of the iron core being coupled with an inner edge of said coil;said external housing and a positioning cover at an open end of said housing being made of metal with excellent magnetic conductivity, and an outer part of said housing being formed with a radial bore hole, whereby an edge of an inner side of said housing in conjunction with an outer face of said iron core forms an attracting holding face for attracting and attaching with each other; and that said iron core is magnetically coupled to a permanent magnet which is fixed at an inner side of said positioning cover, and that the inner side of said positioning cover at an edge of the permanent magnet forms an attracting holding face for attracting and attaching an inner face of said iron core; anda drive circuit independently installed or installed at one side face of said external housing whose power output wire is connected with said coil, so that a positive impulse voltage will be exported and electrical energy is stored in a capacitor when power is switched on, while a discharge current is created to export a negative impulse voltage after power is switched off, whereby the positive and the negative impulse voltage serves to make said coil change direction of a magnetic force generated by said coil so that a push force or a pull force on said iron core will be created for movement thereof, and whereby said permanent magnet will be forced to change the magnetic circuit, and said iron core under a power-off state will be kept at the pre-arranged position.