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Showing posts from July, 2013

Sine Wave Generation and Implementation using dsPIC33FJ

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AC Power Control: Adjustable Phase Angle Control with triac using ATmega8

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Principle of Phase Angle Control Top - Output Voltage Bottom - Gate Drive Signal Image source: Wikipedia (http://en.wikipedia.org/wiki/File:Regulated_rectifier.gif) The photo above clearly illustrates phase angle control: output voltage controlled by the gate drive signal applied to a thyristor. What is phase angle control? That is what I'm going to talk about in this article. Phase angle control is a method of PWM applied to AC input voltages, usually the mains supply. Of course, the AC supply could be from a transformer or any other AC source, but the mains supply is the most common input – this gives the phase angle control method its greatest usefulness. It has of course become quite obvious from the title (and I’m sure most of you reading will already know this) that the purpose of phase angle control is to control or limit power to the load. The power device used in phase angle controllers is a thyristor – mostly triacs or SCRs. (There are methods of phase controlling emp