2. TransformerThe transformer core of LED Lights can be seen as the center of the brain, and the transformer decides efficiency and temperature. The transformer transforms direct current to magnetic energy. If the energy is overloaded, then the transformer will turn off. The transformer mainly includes core and solenoid. The quality of core is important for transformer, but it’s hard to define just like that of china. The general judging from appearance is whether it is intensive and bright, and those with grinded pores are of best quality.