its not that bad, but i do wish ppl would add a comment on the downvote to show why. glad someone else dropped the link :D it might be easy to assume someone else can find such info but in reality people are so into different things that something obvious for one person can be a complete mystery to another. no clue what to search or read to even get there apart from starting physics and electronics courses from scratch and stumbling and bumlbing along to maybe someday find out why that downvote happend.

Glad some people do like to be smart rather than smug, and provide the link :)