Technical development of AC contactor
one of the basic feasible solution is to replace the AC power transformer transformer, and then through the internal rectifier into a DC power supply, but this complex control and Rare.
After the 1980s, countries to study the exchange of contactor electromagnet silent and energy-saving
Because the AC electromagnetic contactor coil is generally used AC power supply, in the contactor after the excitation, usually there will be a high decibel "slightly" noise, which is the characteristics of electromagnetic contactor
