Thyristor Controlled Starting of Induction Motor

Abstract

The project is designed to control AC power to the load by using firing angle control of thyristor. Efficiency of such power control is very high compared to any other method. The project uses zero crossing point of the waveform which is detected by a comparator whose output is then fed to the microcontroller. The microcontroller provides required delayed triggering control to a pair of SCRs through opts isolator interface. Finally the power is applied to the load through SCRs in series. This project uses a microcontroller pic 16f73 which is interfaced through a push button switch for increasing or decreasing the AC power to the load.