Switch

A switch characterized in comprising:

• a static contact;
• a static iron core partially forming a cavity, wherein the cavity has a first opening on a side facing the static contact and a second opening on a side away from the static contact;
• a moving iron core, wherein the moving iron core comprises a narrow part passing through the first opening of the cavity and a widened part immediately adjacent to the narrow part and away from the static contact relative to the narrow part, wherein a cross-sectional size of the narrow part is smaller than that of the widened part, and a platform is formed at a boundary between the narrow part and the widened part and protruding outwards from a periphery of the narrow part, and the moving iron core passes through the cavity through the first opening and the second opening of the cavity;
• a moving contact fixedly arranged on the moving iron core, wherein the platform abuts against the static iron core when the moving contact is in contact with the static contact;
• a coil arranged in the cavity and surrounding a part of the moving iron core;
• a permanent magnet arranged in the cavity and adjacent to the coil;
• a reset piece connected to the moving iron core, wherein the reset piece exerts an elastic force on the moving iron core away from the static contact when the static contact is in contact with the moving contact,
• wherein the static iron core, the moving iron core and the permanent magnet form a closed magnetic circuit when the static contact is in contact with the moving contact.