hi Sarma,mvs sarma said:Eric, As you are already on the process i would like Kris1 to make it work and learn from the design.
I would, in the mean time try and come out with a so called v.2. Perhaps it is more important that Kris1 should apply himself and learn to improve the design.
The problem there are so many things wrong with the design that it would be easier to start again.
Basically all Kris is trying to do is detect a min/max voltage and operate a relay and a buzzer with a start up delay.
It would be easier to design a new circuit from scratch, rather than keep on modifying his present design.
I agree an OP should always try to come up with his own design and post it for comment, I applaud him for doing that.
'Agu' has also pointed out some serious shortcomings in the design, as have other members.
At some point we have to say to the OP, go back to the drawing board.
Regards
Kris:
I would suggest you make on a project board, the individual sections of the design and test them out one at a time, use a variable bench power supply in place of the mains connection.
Try out the min/max 4011 detection part first.