UPS stands for uninterruptible power supply for office [เครื่องสำรองไฟ สำนักงาน , which are the term in Thai]. Its function is to provide uninterrupted electricity to electronic devices during low voltage or electricity disconnection. UPS was not created by targeting computers. In later years it became an important part of our personal computers.
A standard UPS can provide continuous power supply for 10- 15 mins. Higher models of UPS can provide power for more than 10 mins. Other electrical appliances can also use these. They can provide power from 850 VA to 1600 VA and more.
How does it work?
UPS consists of a power inverter and a battery. In conventional UPS, the computer uses the UPS battery power, and at the same time, the battery gets recharged. UPS acts like a middle person, between the circuit board and the computer. It provides a clean energy source for the devices.
When the power supply gets interrupted or drops down, the inverter converts the DC power supplied by the battery to 120 volts, 60 hertz AC power supply.
Types of UPS –
Standby UPS –
These are standard UPSs which provide uninterrupted power supply directly from the battery during low or complete power shut down. The battery directly gets recharged from the AC power supply during the plugin. In case of a power cut, the inverter converts the DC power supply from the battery into AC.
These are mostly used in offices and households. It is also used to protect modems, VoIP equipment, and other devices from a sudden spike or out surge of electricity.
Online UPS –
This has double or delta conversion technique. In double conversion, the device doesn’t get electricity directly from the power outlet. Instead, it passes through a rectifier. At first, the Ac is converted into DC and powers the battery. At the time of power cut, the inverter converts the DC power to AC and supplies to the system.
Line-interactive UPS –
Line-interactive UPS regulated the voltage automatically. It is sensitive to voltage conditions. It balances the voltage deviation.
Units can also provide continuous power back up. In this kind of UPS, the inverter charges the battery during the normal operation. During power interruption, it converts DC to Ac for devices to run.