You may be wondering how uninterruptible power supplies, more commonly known as UPS, work. The UPS is a device that provides emergency power source to equipment when the main power is cut off. It is also referred to as backup batteries. However, UPS are technically different from batteries since its output is AC rather than DC. Normally the main use of a UPS is to give the user enough time to save his/her work, in cases of computers; or to provide some allowance while waiting for the generator sets to turn on.
You should take note that an uninterruptible power supply is different from a standby generator. Standby generators are used to provide power when the main line is disconnected, but this generated power is not immediately available. Usually it takes around 10 to 15 seconds for the generator to give a stable power. This very brief interruption could actually be enough to ruin some of your important work.
UPS is therefore very useful in addressing this brief interruption. Typically, UPS can supply uninterrupted power ranging from five to thirty minutes. This is why, it is important to be aware and have the presence of mind when saving your work if you are working with computers as soon as you experience a power interruption.
The uninterruptible power supply therefore functions as a mediator between the main supply and your equipment. The equipment is connected to the UPS which is connected to the main electrical network. The UPS accepts the alternating current (AC) input, then in order to store it in a battery, the UPS rectifies it to direct current (DC). When there is power interruption, the UPS automatically inverts the stored power to AC. This new output will be enough to power the equipment.
Most of your electronic devices, such as desktop computers, have built-in adaptors in their power supply. It is responsible in converting the AC input to DC output. However this power supply does not store any energy. This conversion happens only if it is connected to the main power line.
Uninterrupted power supply device also serves as protection from power surge. While its main objective is to serve as a backup battery, it also sees to it that the power output is stable. There are occasions when the automatic voltage regulator or AVR is used with the UPS to make sure that there is a stable AC input; however, this may not be necessary since modern UPS are already equipped with surge protectors. Some UPS devices are equipped with sensors that determine whether it will allow a bypass. In other words, the AC input goes directly to the equipment. The equipment is like connected directly to the wall outlet. This bypass happens when the battery is already fully charged.
Moreover, when the UPS senses that the AC input is fluctuating, whether it is above or below the predetermined voltage level, the UPS automatically shuts off the bypass and turns on the DC - AC inverter to supply the equipment. The switching happens instantaneously that it is hardly noticeable. With the UPS one could work confidently and peacefully.
