I’ve always felt that Computer Science is somewhat of a liberal arts major compared to the hardy breed that is electrical engineers. So I’m taking an introductory ECE course to satisfy my own curiosity.
Today we had a simple lab demonstrating digital logic. I prepared part of the circuit on our breadboard and my lab partner finished the rest.
Unfortunately, nothing worked. I spent about fifteen minutes rewiring and pulling apart the circuit until nothing was left but the breadboard and a single logic gate. Even then I still wasn’t getting the output I expected.
I said, perplexed, “Well, I have no idea what’s wrong.” My lab partner stared at the board for a few seconds and then remarked, “Does it matter that you have the power source plugged into the GND line instead of the power line?”
I had pulled apart our entire circuit because I had forgot to plug in the power, once again reminding me that I should keep a safe distance from anything resembling hardware.
Haha, wow BAILOPAN, gotta love it. Yeah, hardware is not my strong point either, but I took an introductory course and had my share of silly mistakes.
I can’t fit an ECE course into my schedule, so I bought a kit and tried to teach myself.
It went over pretty well on the whole; however, there was one odd quirk that stands out more than anything else in my mind:
I was putting together a circuit that made eight LEDs blink is succession (and made a noise everytime the lights switched) – there was one point where the circuit was broken into two halves connected only by a capacitor, and I couldn’t for the life of me figure out what the purpose of the capacitor was. Taking it out or replacing it with a wire caused the circuit to stop working completely, and replacing it with a smaller pF capacitor made the lights blink faster or slower, though I don’t remember which.
Finally, I gave up and decided to go see an electronics professor. I came in, told him I had a question, and showed him the circuit. He took one look at the diagram and, before I even asked him my question, said “This is wrong.”
“Wrong?” I asked, “What do you mean?”
“This capacitor shouldn’t be here,” he said, and pointed to the capacitor in question. “Capacitors are a DC-block – so there’s no way this circuit could work with a capacitor here!”
To this day, I still have no idea how or why that peculiar circuit works.
I am finding the same problem. The professor gives us circuits, and we’re only supposed to understand the digital logic behind them. There are pieces to these circuits that evade my understanding and pique my curiosity. For example, the positioning of resistors or transistors in the flow of one current seemed “backwards,” yet it still magically worked. I couldn’t fathom how this worked.
When I asked faluco (AM’s resident ECE major), he simply told me to continue believing it was magic, since the reason why was out of the scope of our course. I expect I’d need to really learn the physics behind electrical currents to understand everything fully.
Out of curiosity, do you remember what kit you got?
Yes: it was a child’s kit I got from a thrift store for $5 called “Fun with Computer Electronics.” They only give instructions on how to put the circuit together along with the circuit diagram (and very often, with one or the other incorrect), without explaining how it works. I got several books from the library whose names escape me and discovered how (most of) them work on my own.
As a side note, there was one book that came highly recommended to me by every professor I’ve talked to, one of them going so far as to tell me it’s the “Only good beginner’s electronics book in existence.” I picked it up (for a ‘cheap’ $60), but haven’t had time to read it yet.
If you’re interested, it’s called “The Art of Electronics” by Horowitz and Hill, 2nd ed.
Don’t feel bad, I hated doing circuits and other E&M stuff in Physics.
You get an A for effort for that lab though :P.
“Fun with Computer Electronics” is the same kit I got quite a few years back. I never managed to complete the initial setup, even after trying to do so several times in the years since, because the parts hurt my hands too much / wouldn’t go or stay into place / were too fragile.