by : article_lesmith

Locally manufacturing an UPS is quite simple provided you have the knowledge of circuits and can throw in a few components that are required to complete the circuit along with a battery. One can use a precise variable voltage supply to set the upper and lower voltage levels. A charging supply voltage of 15 Volt DC needs to be connected to the circuit. A slider named VR1 is attached to the extreme end and this is attached to the positive side of the battery. Another slider VR2 needs to be turned to the other end, to the end that is connected to the VR1. The voltage of a drained battery is 11.8 volts. It is at this voltage that the test supply is set. When the voltage falls to the test voltage level, transistor turn in again and the battery is charged to the voltage of 13.3 volts which is the full voltage of a battery; i.e. the test voltage is being raised to 13.3 DC volts again. This is done by the VR1.

This is the simplest circuit that is incorporated in a UPS along with the battery. IN this line is introduced the Led for visual indications and the speaker for audio indications.

One of the biggest UPS manufacturer's of today is GE. They have created a standard in UPS manufacture and are the leaders with being pioneers in the industry.

UPS manufacturers keep certain points in their mind when going in for manufacturing UPS. They are a UPS must bridge a power failure ranging from a few minutes to several hours; they must be able to protect over and also under voltages; they must be able to keep transients in the utility powers from reaching the load; it should be able to provide for careful discharge / recharging of the battery and at the same time give protection from low discharges.

Manufacturers must keep in mind the market for which they are manufacturing the UPS, the European market asks for a regulated voltage of 220 - 230 volts and 50 Hz while America and other countries have 110 to 120 volts with 60 Hz. Modern supply units require a power that has a pure sine voltage, while normal invertors supply a peak and a mean value that are not identical. This will cause the SMPS of almost all computers to malfunction.
Modern UPS manufacturers stick to the simple rule of supplying the main line directly when there is main line power and cuts in to the invertor's circuit only when there is a need to use the battery i.e. when the main power fails.

There is another line of UPS called the off line UPS. Manufacturers make both type of UPS depending upon the varying needs of the customers, otherwise with the competition that is existing today it is difficult to sustain in the market.