Umair IftikharAli SajjadImran, Muhammad2015-05-132015-05-132014https://escholar.umt.edu.pk/handle/123456789/1526Motors are widely used in industry, factories and automobiles so there is always a need to devise a system which can control the motor efficiently so that quality and cost effectiveness can be attained. There are two very widely used methods for controlling speed of AC motors. One is variable frequency drive other one is firing TRIAC for varying the speed of AC motor. Micro-controller will get an interrupt by Zero Crossing Detector Circuit and will create some delay from 0ms to 9ms according to the DTMF signal. During call when a key is pressed in cell phone, the other person hears some tones with respect to keys pressed, these are DTMF tones. Mt-8870 decoder IC will decode these tones and will further interact with controller.B.Sc ThesisWirelessThesis