# OddThinking

A blog for odd things and odd thoughts.

### Why I am not an Electronics Engineer

There’s a very good reason why I am not a fully-qualified Electronics Engineer, pushing forward the frontier of knowledge about the next-generation semi-conductors, inventing the next Internet-ready household appliance, and being admired by all the women.

The reason is that electricity doesn’t work.

Well, what I really mean is, electricity doesn’t work they way they teach you it works when you are young.

The rules they teach you are lies; the analogies they give you are confusing.

Here’s how I remember it:

Electricity Expert: Kirchoff’s Rules are the basis of electronics. For example, one of these rules says the total current flowing into a junction is equal to the total current leaving the junction

Young Julian: But, you just taught me about capacitors. They have current flowing into them, but not out the other side, right?

EE: Err… yeah, but only for a short time. It doesn’t really apply to capacitors.

YJ: Aren’t capacitors one of the basic components of electronics? How can a major rule not apply to them?

EE: You don’t understand yet. Let me try something easier.

Ohm’s Law says V=IR, voltage equals current multiplied by resistance.

YJ: Oh, so if I increase the resistance in this circuit, the voltage will increase!

EE: No, the voltage always stays constant. The current will reduce.

YJ: Huh? Why didn’t you say I = V/R then? That way, the constants are on the right, and the unknown is on the left – you know, like they force us do in algebra all the time.

EE: Yeah, whatever. It’s the same thing. Nevermind, did you finish wiring the flashing LED circuit yet?

YJ: No, I think these LEDs you just gave me are dead. I am measuring the resistance – yes, in both directions – and it is infinite.

EE: Oh, that doesn’t prove anything. They have very high resistance at low-voltages, but it drops off as the voltage increases.

YJ: Huh? Didn’t you say V=IR?

EE: Yes, but Ohm’s Law only applies to Ohmic resistors.

YJ: What’s an Ohmic resistor?

EE: One in which the relationship V=IR holds.

YJ: Whoa! So Ohm’s Law is that V=IR, but only where it is true that V=IR? Isn’t that a tautology? You call it a Law of Physics, and it contains no information content!?

EE: Hmmm… Let me make it simpler for you. Electricity is like water flowing through a pipe…

YJ: Oh no, not this one again.

EE: …current represents the amount of water flowing through the pipe, and resistance is like an obstruction in the pipe, and voltage is the water pressure.

YJ: Right, so it is like when I play with the garden hose. If I put my finger over the end of the hose, the water will shoot out faster.

EE: No, no! The electricity doesn’t speed up or slow down.

YJ: What? So it’s nothing like water then. Well, what’s the equivalent of a capacitor in this analogy?

EE: Well, um, it’s like a swimming pool being filled up; the capacitance is like the size of the swimming pool

YJ: Is the water pipe filling the pool from the top or the bottom?

EE: What? At the bottom, I think.

YJ: Well, what happens when it overflows.

EE: Err.. I kind of empties all at once – err.. okay forget the swimming pool. Consider the analogy of a bucket, think of it like a bucket with a collapsible bottom.

YJ: Talk about an analogy that doesn’t hold water! Where’s the pipe? You fill buckets from the top.

EE: Umm.. er…

YJ: Can I play with my Commodore-64 now? Software makes so much more sense than this.

1. Genius.

2. OK so you’ve got this bath, right? And it’s conical …

3. Listen, pal. If you don’t shut up about this the boys will come around and make you learn about near-field antenna design. We try to make this stuff easy for you, but there’s always some joker like you that wants to crack wise. “How can you have an imaginary current”? “What happens when the battery runs out of electrons”?

That’s a nice-looking computer you’ve got there. Be a shame if all the transistors in it just stopped working.

4. Once, in primary school, we were learning about numbers. Subtraction, more specifically. Our teacher was saying things like “what’s 7 – 4?”, etc. We were all answering them, until he said “what’s 4 – 5?”

I said “it doesn’t exist”, and my teacher said “that’s absolutely right”. I felt like the smartest kid in the entire class. However, he was lying, like all of mathematics.