low frequency to high frequency in electronic ballast

[phobos1]

Can someone tell me how ac low frequency is converted into high frequency in electronic ballast. I learned something is done by toroid transformer in it. Tel me some techniques to do this frequency conversion

 

[schmitt trigger]

If you are talking about changing from 50 or 60 hz to 10s of kilohertz?
The answer is very simple, electronic ballasts are switch mode supplies , but with specific characteristics suited for a lamp load.

Rather than attempting to provide you wit an incomplete description,..........please check the International Rectifier web page. For lots and lots of information, go to irf.com and in the "technical library" tab, search for lighting solutions.