I know you are from India but I don't know if you are from any college in TN - just curious.. I have been watching this thread and surprising thing is, all the senior people have been VERY considerate to you !

And equally stunning is your refusal to learn and do things the right way. Mike has posted schematics, and so has Kai including his comments. Erik wanted to know what derivative you use - not once but twice. And still you have not said what it is nor responded to any of them.

All you want is to make that silly relay click - OK it does click, then what ? You want to unclick it ? Engineering, my dear, is more than that.

After all this, one would have expected you to respond like an engineer with specific data and ask for specific help instaed of asking for a "better way" - do you mean that the suggested way is lousy ?

Finally, I dont mean to upset you - it is your way of approaching a technical problem that kind off needs correction. Hundred professors cannot teach you what these senior people posted in a few paragraphs.

Help like this does not come often - and when it comes go for it with all your limbs.

Raghu