Hi Luciano,

Have you built & tested that circuit? ... (looks comprehensive at first glance)

I usually do most of my projects from scratch. But I do get ideas from other people's circuitry. I know that there's a lot of people around that just slap together odds & ends that they find in magazines, from books & on the internet. Some of them even try claiming it as their own. This is one of the reasons why I procrastinate about doing anymore projects for publication.