DESIGN AND CONSTRUCTION OF HIGH STABILITY UNINTERRUPTIBLE POWER SYSTEM

A 500 watts uniterruptible power supply system was designed, constructed and tested. The circuit was designed using the quasi-square-wave which consists of two square waves generated with a clock generator which is amplified and superimposed on each other to approximate a sine wave at the output of the transformer. Results of the test performed on the system indicate that the rate of the voltage drop per hour depends greatly on the power consumption of the applied load. MOSFETs was introduced as switching devices at the output sections as the MOSFET transistors are far better than common bipolar transistor that were commonly in use. The tests also carried out on the oscilloscope show that the output of the equipment was very similar and close to the sinusoidal waveform from the commercial power supply (PHCN).