Hi! I need a help in my lighting related project. Actually i already made a electronic ballast, with the function of dimming. We can dim the lamp by applying 0 - 10V dc supply to it. Dimming range is from 100% to 3%. Now i want to include a new function in it i.e. i want to put a timer in it. The main function of timer will be to dim the lamp automatically after 7 hrs up to 3%. I need help by using both the way i.e. by using analog IC (555, etc.) or by using microcontroller. Well, in the electronic ballast which i had developed i used analog IC's. I had used a comparator IC for dimming purpose.

Well, waiting for reply.......

Thanks,
Alok

So you want the light to be at a certain level of brightness for the 7hrs and then after the 7hrs, dim to another level which may be as low as 3%? Do I understand your question correctly? Can you post a schematic of what you have built already?

Yes you are right. Can i give u the schematic of the dimming circuit? Because it is not possible to give the schematic of whole electronic ballast. By the way i will also give u the block diagram of the system. Can i get ur email id, so that i can forward it into ur inbox.