The case is made of PC/ABS alloy, which is characterized by high temperature resistance, high mechanical strength and environmental protection. 

As shown in Fig. 1(B) and Fig. 2(b) , the main winding (6) core is made of oriented cold-rolled Silicon Steel Sheet, as shown in Fig. 1(b) and Fig. 2(B) , the secondary winding (5) is made of permalloy, which has the characteristics of stable performance, high mechanical strength and high permeability, and the enameled wire is made of high strength enameled wire, which has the characteristics of high insulation strength and high temperature resistance. 1-terminal 1S1; 2-terminal 2S1; 3-terminal 1S2; 4-terminal 1S2; 5-auxiliary winding; 6-main winding