Abstract: Power quality is one of the most talked about topics these days. Both the power utilities and customers are quite concern with the quality of the power supply, whether it be the power generated by the power utilities or the power consumed by the customers respectively. They need these supplies to be at its optimum value so that the cost is efficient; otherwise problems such as over voltage, under voltage, voltage swell, voltage sag, noise and harmonic caused by the disturbances in power supply could be disastrous. Several methods have been suggested and applied as the solution to these problems. One of the methods is by employing on-load power transformer with tap changer, where the output voltage of the power transformer remains constant irrespectively to the input voltage or variation of the load. The existing mechanical on-load tap changing power transformer has few disadvantages, as it is slower, produces arching each time the tap setting is changed and needs regular maintenance. With the emergence of high power semiconductor devices such as triac, problems associated with the mechanical on-load tap changing power transformer have been properly rectified. In this study, a small prototype consisting of triacs as the switching devices and microcontroller as the triggering circuit has been constructed. The results obtained from this study show that the prototype has a faster time response of approximately 0.4s for the circuit to react to any load changes, produces no arching problems as it has no mechanical contact and requires no maintenance. The system has been tested for reliability and proven to be reliable in maintaining the output voltage of the system.