Transformer is an electrical or electromechanical device, made from two coils of wound wire that are connected so that one of the coils will send electricity to the other. It is one of the most common and critical components for LED driver.
The transformer can either increase or decrease the level of voltage running into it. In the case of LED, transformer is used to convert line voltage to low voltage that will then be applied directly to the LED light product.
The temperature of the transformer is a key factor that affect the LED Driver. Generally speaking, for low power driver, the temperature rise of the transformer should be limit to 40-50 degree, because the higher temperature will lead to the decrease of inductance, current and power, even may blow out the transformers line.