Both of the tests and the heating need relief from the power supply to up-flow and then make the low voltage current reach thousands or more 10,000 amps. This series product applies the inner air cooling structure, and can be divided into single-phase and three-phase transformer. The product has good ventilation and reliable insulation system. The high voltage is 200V, 380V and 650V, and the low voltage is according to the up-flow current to form itself system for the industrial and mining enterprises, and it is usually used in the low-load resistance oven, ceramic sintering furnace, clean float class material heating, and the quality graphic alloy components sintering furnace. It is usually need the voltage regulator when applies this series of product to make the low voltage achieves the no-class regulation.