Early Adventures in Electronics

Oct 4, 2010

So, I have a confession to make.  I've never soldered anything in my life. I'm not sure exactly how I skipped this developmental step.  My parents were very supportive in my early quests to learn sciency things: I had a microscope, lego, access to simple woodworking tools... all that wonderful stuff... but no electronics kits. Probably because, as the comic suggests, I'm one of the clumsiest people on the planet. Maybe their house insurance didn't cover offspring idiocy.

Whatever the reason, I managed to go through all of my childhood and even several university electrical courses without ever soldering anything! (We always used breadboards)  These days I've got the itch to test my personal boundaries and try new things, so I marched down to the local electronics shop and bought an assortment of things, DETERMINED to try soldering something together. If my destiny is to fail spectacularly, so be it!

Let's back up for a moment. In case we have non-techies in the audience, soldering (pronounced "SAW-tering" in US English) is the process of joining a conductive material to electronic components so electrons can flow between them. (I believe it was lead at first but it's now a form of... tin?)

An electronic circuit can't work without a continuous path of metal. The solder acts as a bridge between components (like the battery, resistors, LEDs) and the circuitboard (which has paths of metal embedded into it).

Back to the story, I'd purchased the running microbug kit, pictured above. Any eight year old could probably put this together, so it seemed like a good place to start.

Here's my workstation.  The red handled thing is the soldering iron. The complete instructions are laid out there. To be as multi-lingual as possible, all of the steps are spelled out in crude pictograms. Some are easier to understand than others. Reminds me a bit of origami instructions! The metal tube-looking thing is a coil of solder that came with the iron. I'm sure I'll need more soon!

Here are the two types of resistors used in this circuit.  The little coloured lines are a code for resistance value (Ohms). According to the kit, brown-black-brown is 100 and red-red-brown is 220.  I wasn't really interested in verifying that, I just wanted to get to THE BURNING

Stick it in the appropriate slots and feed the wires through... flip the circuit board over...

... and there we go! My first ever solder. I really can't tell if these are good or not, they are probably terrible. I tried really hard to get the fabled "volcano shape" but I was also really worried about not having enough solder to make the connection. So I erred on the side of caution and put probably way more solder than I needed.

Repeat as directed

Once the resistors are down, the kit instructs you to solder down the fancier components... transistors, a switch, and these little doohickies that I learned later are light sensors! (in the kit they were just referred to as 'LDR'. NOW I KNOW)

LEDs. I learned that the SHORT leg is the cathode, and you need to make sure that goes in the BLACK side of the indicated hole. I'm sure I will screw that up someday. Mayber there's a mnemonic. Short-Cathode-Black. ShCaBl. The short black cat jumped in first... this is terrible nevermind.

Definitely the most exciting part of the kit for me were these little motors. Motors!! They're so adorable... Most of the motors I deal with are the size of an ottoman or larger (hundreds of horsepower), so it's exciting being able to hold one in the palm of my hand.

The instructions had a strange pictogram of what looked like a police baton pointing to the sides of the motor. I figured out that they wanted me to use a metal file to roughen up the sides so solder would stick to it. I just roughed it up with my snips since I didn't have a metal file, seemed to work ok. Getting them to stay at the weird angle (as pictured) was a challenge, I needed like six hands to do this!

Most of the components are down now, including the little motors. As you can see there are a variety of solders, probably ranging from terrible to oh-God-why in quality. By the end of it, the best technique for soldering seemed to be a sort of chopping of the solder wire a few mms away from the target. This seemed to reduce runaway solder. If you miss, the solder cools into a neat little sphere that you then have to chase around the board with the tip of your iron. Fun, in a way, but I can tell this is not ideal.

This was the hardest part for me, bending the connector wire to the lead and through the hole to the rest of the board. Very difficult to bend, I was certain I was going to break something.

... but I did it!

In the end, I put the batteries in this sucker and... well... it did something! But I screwed up in several places. First, the switch didn't work.  I think this is because the three connections were touching a little. It was an accident! I tried to slice them apart and clean it up a bit, but I guess it was a lost cause :(

Beyond that, only half of the circuit seems to be working... One motor and LED (on the same side) don't work, so when you turn it on the poor thing just vibrates awkwardly in circles. The light sensor worked, though, and I had fun shielding it with my hands and uncovering it.

So, all in all a noble failure, I think. I learned a lot considering I had to get over my fear of burning myself horribly and I'd never soldered anything ever. I'm tempted to buy the same kit and try again, but I'll probably just buy a different kit.  I WILL MASTER THIS YET