See the post "Passive circuit to rectify pulse signal".
This question clearly had some problems, and I both downvoted and voted to close it. The downvote was for general sloppiness, pre-supposing a answer, and leaving out stuff that should have been obvious that it would be relevant or useful. The close vote was because it was difficult to tell what was being asked.
However, after some comments, the OP added more information to the question and a reasonable answer was possible. 4 votes to close and 3 downvotes had accumulated until the question finally got to a answerable state. I have no problem with that since it was a mess originally. I you don't like the downvotes or the chance your question will be closed before you fix it, write a better question in the first place.
I started to write a answer, but then a banner popped up that the question had been deleted. I thought maybe the OP got frustrated, but is was deleted by community. That's the part I don't understand. First, I don't see the reason for deletion, considering by that time the question had been salvaged. Second, how can community delete a question so quickly that hadn't even been closed and had only 3 downvotes? If a mod did it, then isn't the mod's name shown? What is the mechanism by which community can delete such a question?