Talk Nerdy to Me Pt. 1: Intro and Digital

Hi all,

It's been too long since I've blogged, but now my girlfriend is getting on my case (check out her blog at http://loveislife0lourdes0echagarruga.blogspot.com/).

I've had this idea for a set of posts but I never followed through. Basically, I would like to write about electrical engineering concepts, mostly related to what I do, but in terms that anyone can understand. The topics covered will be very high level and simplified. If anyone wants to learn more or have some discussion, let me know.

There are several reasons for this. First, hopefully it will help many of you understand electronics and the amazing technology that they hold. Secondly, it will help me develop my communications and teaching skills. This was all inspired by my girlfriend. She is extremely smart, with 2 BA degrees and an MA (and not the bullsh*t ones either). However, she has no understanding of what I do. Part of this is my fault since I am not a very good teacher. But electricity is difficult to grasp (Physics 2 anyone?). I also have no idea what she's talking about when she talks about her school work.


So... For the first post, I'd like to cover the concept of Digital...


DIGITAL


Digital is a specific form of electrical signal. The easiest and most common uses are in music (MP3's) and communications (cell phones). 


Regular signals are analog, the opposite of digital. Analog is a signal that has an infinite number of possible outcomes(CSZ). Think of speech. The human voice can produce a near infinite number of sounds. 


This creates a problem. With so many possible sounds, it will be difficult to understand all of them. Think of a game of telephone. Even though everyone speaks the same language, there are still many possible words in the message. Each person along the way may distort the message until the final message is totally different from the original. This is what happens to an analog signal in any channel, whether it's a wire carrying music or the air carrying a cell phone signal.


In order to solve this, digital limits the number of possible outcomes of the electrical signal, usually to two possibilities, "on" or "off". This way, there is less of a chance for the signal to be misinterpreted. Now imagine if you could play telephone and instead of the message being a whole sentence, it can only be the number "1" or "0". There is a much smaller chance that the message will be distorted.. This is why digital is gives us clearer sound in music and phone calls, and higher quality video (DVD).