Abstract:
Digital equipment such as computers, telecommunication systems and instruments use
microprocessors that operate at high frequencies allowing them to carry out millions or even
billions of operations per second. A disturbance in the electrical supply lasting just a few
milliseconds can affect thousands or millions of basic operations. The result may be
malfunctioning and loss of data with dangerous or costly consequences (e.g. loss of production).
That is why many loads, called sensitive or critical loads, require a supply that is protected.
Many manufacturers of sensitive equipment specify very strict tolerances, much stricter than
those in the distribution system for the supply of their equipment, one example being Computer
Business Equipment Manufacturer’s Association for computer equipment against distribution
system disturbances. The design of this uninterrupted power supply (UPS) for personal computer
(PC) is necessitated due to a need for enhanced portability in the design of personal computer
desktop workstations. Apart from its original functionality as a backup source of power, this
design incorporates the unit within the system unit casing, thereby reducing the number of
system components available. Also, the embedding of this unit removes the untidiness of
connecting wires and makes the whole computer act like a laptop. Not to be left out is the choice
of a microcontroller as an important part of the circuitry. This has eliminated the weight and
space-consuming components that make up an original design. The singular use of this
microcontroller places the UPS under the class of an advanced technology device.
