| 摘要 |
A closed magnetic circuit for alternating current includes a moveable armature and a coil 1 arranged on a former. Said armature consists of a unit which contains two iron parts 2, 3, arranged together with an intervening permanent magnet 4. Said unit is placed inside the former and guided therein to accomplish distinct armature movements. Said iron parts 2, 3 have different flux cross section areas, wherein the flux cross section area of the first iron part 2 is much less than that of the second iron part 3. The first iron part is arranged in the magnetic circuit so as to be essentially saturated by the flux from the permanent magnet. The flux <IMAGE> 4 produced by the coil is thus forced through the second part of the magnetic circuit, which can work with a relatively large air gap. <IMAGE> |
