The utility model provides a thermal technology uses circumscribed switches on device perpendicularly, belongs to the electric power tech field. The utility model discloses a support, the first fixed plate of lateral part horizontal installation and the second fixed plate of support, installation electro -magnet and supporting seat on the first fixed plate, two electrically conductive clamps of supporting seat upper portion installation, the electrically conductive clamp including conductive seat, two deflectors and two conducting strips, the conductive seat is installed on the supporting seat, the utility model discloses a telescopic link can make two contacts coordinate with the same dynamics and electrically conductive the clamp to make the contact and lead electrical slot to keep in close contact with, reduce contact resistance, avoid contact heating to damage. The utility model discloses a first spring can make contact and electrically conductive the clamp break away from with iron plate promotion when the electro -magnet is not switched on.