Before your computer can operate properly, it needs an adequate amount of electricity. Through the power supply system’s switcher technology, power deliveries the electricity once the alternating current (AC) input from an electrical outlet is converted into direct current (DC) input for your computer. The power supply is typically known as the “switching power supply.” This is a metal box found in a corner of the computer case. In most cases, power supplies are visible at the back of the computer that contains a power-cord receptacle, cooling fan and off/on switch.

As various components of the computer have different requirements, there are three voltages typically provided by a power supply: 3.3 volts, 5 volts, and 12 volts. The digital circuits of most computers use the first two voltage rails while the 12-volt rail is used in disk drives and fans. The main specification of power supplies is using wattage to rate the current they use up. In the early 90’s, the typical power supply used around 150 watts. But as the advancement of computer technologies grew, the need for higher wattage arose. Thus, you are now able to purchase 450 watts or greater.

The emergence of higher-wattage power supplies led to many believing that these systems are better for their computers. Apparently, they misinterpreted that installing a large-containing-wattage power supply would safeguard their computers against under-powering the system, and at the same time, draw only the amount of current required. However, this notion is not advantageous at all, as large power supplies can produce more heat. As power supplies are rated through wattage, generating more heat would mean more wattage used. Thus, more wattage used would also mean higher cost for the power.

Uninterruptible Power Supplies , or UPS, are devices that maintain a constant supply of power to any equipment connected to it. UPS equipment is used to provide power supply in the case of power failure. It is an emergency resource of power, which helps to operate electronic equipment at the time of power failure. UPS is mainly used to protect computers, telecommunication equipment and other expensive electrical equipment in which unexpected power disruption could cause injuries and serious business disruption or data loss. UPS units come in various sizes and of different watts i.e. from 200 VA to several megawatts.

Earlier UPS were used to be very expensive and it was used only in expensive computer systems and where the power supply was interrupted frequently. With reduce in price it has been more commonly used across data centers and business computers. Today communication application and critical computer demand power protection system which are extremely reliable and flexible and to meet this demand an uninterruptible power supplies proves to be the best of all the option. UPS proves to be invaluable in case of electrical disturbance and a reliable and efficient UPS will keep the computer running for few minutes after the power disruption so that one gets the time to save the data and shut down the computer. Another vital function of the UPS is to stop power anomalies such as voltage spikes, power sags, and surges from reaching the computer or any other electronic device that can cause immense damage to them. With more frequent power cuts and power disruption UPS are proving to be quite helpful and efficient.

There are four types of UPS system such as standby, online, line-interactive, and ferroresonant. Standby UPS provide protection from outages and small power spikes, and power sags. When power failure occurred, a switch is activated and power is then supplied from the battery. Online UPS provides much greater level of protection because of its superior power conditioning capabilities. In this type of UPS, A/C current is used to charge the battery and the battery supplies the A/C power by passing its D/C current through a power inverter. This type of UPS is the best choice for critical application or where high availability is required. Line-interactive UPS passes power through the noise filters and surge suppressors before going into an inverter. Inverter which is on the entire time act as a battery charger and in the case of power failure will switch to provide backup. Ferroresonant type of UPS uses a ferroresonant transformer as a power buffer to keep power supplied while the UPS switched to standby power. The energy buffer of the ferroresonant greatly reduces the chance that the protected equipment will be affected during the transfer time from the primary to secondary power sources.