Saturday, March 7, 2009

My Hand Made FM transmitter




Today, I'm just gonna show you the FM transmitter that I made during my EECE252 lab. This course is about signal and processing. We were given two choice wheather to build FM transmitter or AM receiver. I chose to build FM transmitter because FM is way cooler. huhu

Basically the circuit is consist of input (microphone), mixer (BJT) and antenna (wire). There is also a tuner (blue device) to tune the transmitter to desired frequency.

FYI FM signal consume huge bandwidth but as a trade off the signal is almost imune to inteference while AM signal is vice versa.



This is how it works: there is two different signals, one called information signal and another is called carrier signal. The info signal which contains our desired info i.e. voice, music, data etc. is then modulated to the carrier signal which is basically a simple sinusoidal wave range 88MHz to 108MHz (for standard FM radio spectrum) that carry our info wirelessly accross the medium (air) to any radio (FM receiver).

We also learn the mathematics behind it. For FM, after modulation the frequency respond has Bassel Function property and it is depends on the modulation index which is entirely depends on the designed circuit. For AM simply find the product of two wave function.Here calculus play a big role.



So I did it within 45 minutes but only desparation I get. I tested it using a conventional radio but no sound coming out from it. I went home and try to troubleshoot it using multimeter but failed. Sigh!.... I saw others manage to tap the microphone and heard results on the radio which is so awesome. This is my first time building a real life FM transmitter (although I suck). Now I'm seeing my future as an electrical engineer become brighter and brighter. :)

Sunday, February 22, 2009

Engineering Week







nass_sare: masuk eggdrop jom
are_nan1611: fuh bile?
nass_sare: 16 feb ar
nass_sare: isnin
are_nan1611: isnin??
are_nan1611: hurm ok2..bleh kot
nass_sare: 1230
nass_sare: ha
nass_sare: cool
are_nan1611: ok2

That was my my instant massage with hanan before the start of engeneering week. certainly "the heat" was felt. For us Malaysian here in vanderbilt everyone was affected by it regardless we participate or not. 

Before further reporting about Engineering Week here at Vanderbilt let me tell you a bit background about Vanderbilt University and also our School of Engineering. Vanderbilt University is ranked 18th place nationally while our school of engineering is ranked 42nd. This is quoted from US News & World Report 2009 edition. If you don't believe me you can search at my search engine-ering. There is about Malaysians 130 undergrads here and all of them took engineering. Interesting isn't it? Done with the briefing, if you have more question you can shout at my box or leave a comment.

Below is some of activity we have done in the Engineering week. well... one picture can tell thousands stories.



Egg Drop Competition


 i want to buy buble tea if i win $400


video
poor egg


rest in peace




azlan and baba on top of the world

iCreate Robots Competition


the main actor

the obstacles

Fastest Geek


Haziq with his special pose


try again next year naser



muhaimin strugling to be the one

the grand prize DELL XPS 1530

Tower Building Competition


zed in action

Thats all for now. see ya next week!!

p/s: sorry zed... hehe

Friday, February 6, 2009

Engineer

ding! I entered the lift

"How are you?" said the African American male with his girlfriend with his unique accent.

"I'm good, how are you?" I replied.

"good! what are studying here?" he ask out of the blue.

"Engineering"

" what kind of engineering?"

"Electrical and Computer Engineering"

"man! you gonna make a lot of money I tell you!" suddenly he get fired up

"yeah, I think so....but I'm thinking of becoming a lecturer though" I replied.

ding! I walk out from the lift

"have a good night!" I said.

"you gonna make a lot of money I tell you!" he repeated the same thing for the third time.

and then I left thinking about the huge amount money that I'm gonna make.... ha! ha! ha!

Who is an engineer?

The well known definition of engineer is the person who applied science and mathematics to solve problem, issue, crisis, need of people in daily life.

In my perspective that definition is not wrong at all, others always thought that engineer is the person who makes a lot of money. In some way it is true but the main idea is engineer is a problem solver.

In the 20th century there are a lot of invention and majestic building that has shape the world physically and culturally were made such as radio, computer, cellphone, fast cars, bullet train, airplane, WTC, Petronas Twin Tower and the marvelous of the world that we took for granted. This are all made by engineers and I am going to be one of them.

Our Priority

Energy crisis is our main concern. Now everything that is made has to be energy conserve and renewable. The scarcity of oil and higher demand of energy consumption is the main cause. Then, whoever enter this field is the one the has the highest probability to make huge amount of money.

Another field of interest is nanotechnology. This is a new field which only starts less than 20 years but was predicted 50 years ago by Richard Feynman, some say he is the father of nanotechnology. Now most of the stuff is going nano from microchip to nanochip, microscope to nanoscope. Observing and moving a single atom is common these days. After we manage to manipulate the material in nanoscale we can change their property (i.e. density, hardness, conductivity etc.).

One of the wonder material of the engineering field is the carbon nanotube (CNT). Its cheap yet strong and light. Engineer in this field is highly demanded and I recommend you to learn about it.

Cool Stuff

Look at this video; speaker made from array of carbon nanotube shown during my signal processing class. It was made in China, that explain the music selection.


video

  • The speaker was stretched yet the sound quality still remain excellent.
  • Very thin and can be placed anywhere you could think of.