The invention deals with a kind of switchboards, especially involving contactors, cores and driving circuits. The invention has solved three problems of high driving power, high consumption and short service life in current contactors, and has provided a LCDC contactor inlaid with driving circuit and controlling port. LCDC contactor in this invention consists of field coils, movable and fixed cores. The fixed core is folded with silicon-steel sheets, and the permanent magnet laid in the fixed core. LCDC contactor includes driving circuit inside, the field coils are connected with driving circuit and the circuit connecting external power is used to control signal of driving coils. This invention provides a controlling system constituted of the LCDC contactors. Low power consumption, effortless driving, long service life are the main beneficial effects. The LCDC contactor can directly employ nominal voltage DC 24V switching power with a remarkably energy-saving effect.