What does a rectifier do?

A rectifier is a rectifier device, which is simply a device that converts alternating current (AC) to direct current (DC). It has two main functions: first, it converts alternating current (AC) into direct current (DC), which is filtered to supply the load or to the inverter; Second, the battery is charged at a voltage that is charged. Therefore, it also acts as a charger. 　

What is the difference between the role of a ballast and a rectifier 　　 　

A device that converts alternating current into direct current is called a rectifier. 　

According to the rectifier device used, it can be divided into mechanical, tube and semiconductor types. Inductive ballast is an iron core inductance coil, the nature of the inductance is that when the current in the coil changes, it will cause a change in the magnetic flux in the coil, resulting in an induced electromotive force, which is in the opposite direction to the direction of the current, thus hindering the current change.