Regulating ac fan 220v using arduino

I want to regulate the speed of a ac 220 v fan using my arduino. The basic is for different temperature it will give different speed. Now the real problem is i know how to control the speed of dc fan using PWM output but have no idea of how to control ac fan. So pls help me.If you have schematic, much better.

Note- I heard there is something called TRIAC but i do not know its working. Further there is a restriction of using single chip triac in my project so i have to build a TRIAC. I do not know soldering.

Hi, do I understand that this is a project for an educational course, can you tell me what is the course, or subject name.
It seems strange that you know nothing of triacs, or soldering but are being asked to produce results.
What level are you at and have you done any programming?

We are here to help, but need information from you. We will help you in the best possible way, that is not doing everything for you but guiding through the steps to get a project working.

Use google to look up what a TRIAC is, you cannot build one it is a an electronic component.

Tom.... :slight_smile: