Microcontroller based Automatic dimmer circuit which works on 240V AC

Hi Friends,
I have planned to do a project on dimmer cicuit.

Project Requirements:
I want to connect four bulbs(each of 60 Watt)to the controller which works on 240Volts AC current.At first, all the four bulbs should be in dim condition .The bulbs should take 3 min to gradually become brighter.Now the bulb should stand about 1 min in brighter condition.Again the bulb should take 3 min to become dim and agin this process shold continue...........I have planned to use 8 bit philiphs controller P89V51RD for this project..........If any body have the source code and circuit please post it as soon as possible.

Thank u with Regards,
Sagar H

school project?

Dear do try yourself, inform us when you got some problem in it.
I think you should use Digital voltage regulator IC.
DS18050 it is a potentiometer, vary its resistance as we apply clk to it.
This will be an easy solution inshallah.

we can help if some problems comes, no need to use DS18050 . use triac to drive the bulb just check zero-crossing and fire the triac with proper firing angle, and if using normal bulb make a min set value after a level bulb wont blow

Hi,
I think best would be to use your microcontroller and external circuitry to detect zero crossing, then fire the triac at different angles, in this case, after a specific delay, the delay being the same for both positive and negative cycle. Use an MOC3021 or something similar for triac firing. This would provide isolation as well as easy control of the triac with plenty of current capacity. For the theory about phase angle control read on Phase fired controllers - Wikipedia, the free encyclopedia


Hope this helps.
Tahmid.