Getting Closer.

After successfully learning how to properly breadboard a circuit last week, it is finally time to start building my first circuit board.  This week we etched and drilled our circuit board.  To describe the images below:  First we start with a blank copper circuit board with a layer of photoresist on it.  A pattern is then placed over the board and exposed to a black light for a couple of minutes.  After the board has been exposed, it is developed.  The developer washes all of the photoresist off of the circuit board.  From the developer, the circuit board is soaked in a bath of ferric chloride.  The ferric chloride washes away all of the copper from the pattern that was burned into the circuit board in the beginning of this process.  After all of the copper is washed away the circuit board is complete.  Before soldering a circuit board, the painstaking process of drilling is next.  200+ holes were drilled into this board.  In the final images you will notice some scratches on the circuit board.  The copper didn't completely come off in a few places and was scratched off with a razor knife.

 Exposing the circuit board

 Into the developer

 Ferric chloride bath

 ALL DONE!

Breadboarding.

To start putting my knowledge of circuit design together I began breadboarding my first circuit this week.  Like anything I do for the first time, it usually takes longer than expected.  I think I ha to take my breadboard apart three different times, before I eventually nailed it.  Breadboarding is a way of testing a circuit, before the circuit is etched or soldered together.  In the early days, an actual breadboard or wooden slab was used for this process.

As you can see from the image, circuits are placed on the breadboard, and then are connected to each other in a very specific manner.  A circuit diagram is my instruction manual for this.

I finally completed this yesterday, and today I will be testing it to see if it works.  Fingers Crossed!

Lions, Tigers, and Gamma Rays, OH MY!!!

Our group decided what sensors we will be using this week.  The payload will be taking pictures as well as live video to document the payloads journey to 100,000 ft and back down.  We will also be observing elevation, temperature (inside and outside of the the payload), acceleration (will discuss this later in the post), particulate density as the payload reaches near space, pressure, atmospheric moisture, and possibly gamma radiation.

I have started to do some preliminary research to see how complicated it is to build a geiger counter type sensor.  Luckily for me, there are lots of geeks in the world, and found countless technical schematics for building a sensor that will detect gamma rays over a given period of time.

It looks a little something like this:

Until next week,

Mark

Breaking Stuff

The project I am doing this semester requires planning and preparation.  Next week we will be ordering all of our sensors for this project, which means that this weekend the group has to figure out what we want to observe as our payload enters near space.  Keeping in mind that we have certain voltage and power usage constraints to our system.  Up to this point we have been learning a lot about the engineering design process.  Today we learned about powering our system.  Discussing how resistors and voltage regulators will be crucial to our payload design.

Monday our group will be sitting down and deciding what sensors our payload will use.  We have a few limitations, but I think that this part of the process should go smoothly.


Last week we began designing payload enclosures.  To test them we filled them with 1kg weights and threw them off of our balcony.  Enjoy!