A rectifier (in English: rectifier) is a device that converts alternating current (AC) into direct current (DC), and can be used in power supply systems and for detecting radio signals, etc. Rectifiers can be made of vacuum tubes, igniter tubes, solid-state silicon semiconductor diodes, mercury arcs, etc. On the contrary, a device that converts direct current (DC) into alternating current (AC) is called an “inverter” (inverter).
In a standby UPS, only the battery needs to be charged, and no power supply to the load is required, so there is only a charger. In a dual-transformer UPS, this device supplies power to both the inverter and charges the battery, so it is called a rectifier/charger.
A rectifier is a rectification device. Simply put, it is a device that converts alternating current (AC) into direct current (DC). It has two main functions: first, it converts alternating current (AC) into direct current (DC), filters it, and supplies it to the load or the inverter; second, it provides charging voltage for the battery. Therefore, it also functions as a charger.