Price. Why spend $4 where $0.05 will do, and will likely never fail anyway? It's a last ditch protection system, not really something that should be tripping all the time.

That said, it used to be fairly common to have breakers on a couple circuits (headlights, for one).

In addition to cost, I'd suppose reliability might be a second consideration. Breakers have contacts in them, which with enough vibration and temperature/humidity cycling might fail, I guess... whereas a fuse has none.

What else.. fuses are faster, better current breaking capacity for DC (at least at this price point). I'd guess the tempco might be better too. (the trip point both devices moves with ambient temperature).

That's how it generally works already. Important stuff is on one CAN bus (ECU, ABS pump, auto trans controller if it has auto trans, airbags, etc). All the secondary stuff like door modules (controls locks, windows, etc), cabin illumination, the radio/navi and whatnot are on a secondary CAN bus (or LIN, or..).

This way if your rear door module dies and manages to take down the (secondary) bus, the car still runs.

I don't see much point in securing it, as you need physical access anyway. I'd rather see it go the other direction, standard, open interface, instead of each manufacturer using a proprietary communication scheme. (CAN only defines lower layers).

This is like suing computer makers for people being able to hack a computer they have physical access to. It's not possible to prevent.

That's also how ethernet works... differential transmit and receive signals, transformer coupled for isolation. (to prevent ground loops and such).

Shutting off all the electronics on a fly-by-wire plane seems like a fairly bad idea.

Here's the rules, FWIW. Pennies are only valid to 25c.

These ran NiCd cells. Here's some TL;DR from NASA about a variant of NiCd they use(d), not sure if it applies here.

http://www.nasa.gov/offices/oc...

Short notes:
Fancy NiCd, Higher density and sealed. They rely on precise chemistry to be hermetically sealed units (lean on one element, for limiting and only O2 production).
High pressure at full charge (~60PSI at room temp), higher if things go south, Pressure drops with charge state.
Excess discharge causes hydrogen production.

So, tin can, pressure changing with charge cycles (metal fatigue over many cycles?), H2 production, O2 production... maybe there is some chance for catastrophic failure there.

http://en.wikipedia.org/wiki/R...

Though the units in question do have batteries, which have historically been of the NiCd variety, and are in this case as well. I'm not sure if any newer satellites use newer battery tech? (NiMH or some sort of lithium ion..).

Aluminium is 30+ cents a pound, that's enough to buy some glass. They'll have to steal 10x as much to make the same money, but...

Many do... but not Russia, which happens to be where the guy is.

It's thinned about 25-50% with naphtha so that it flows. "diluted bitumen".

LiFePO4 would be well suited to things like cordless tools and the like. iDrill?

There's no switching (or otherwise) power supply in a SD card though. Not much of anything other than flash and a controller.

I'd imagine more harmful to ingest/inhale uranium ore... in addition to radioactivity, uranium is also a heavy metal like lead. (in both senses of the term "heavy metal".)

However most ore is quite weak, with 1% being pretty decent... I think it's economical to mine it as low as 0.1%. A few mines in Canada are near 20%, though (which I suppose is related to Canada being the biggest producer... 1/5th the ore is end product, instead of 1/1000th!). Ore will often have lead and such in it as well (decay products), which is also toxic.

It might be different in the US, but in Canada they always had terrible stock. So if your thing didn't have a broken lamp or speaker, or a dead battery - you were SOL, as they didn't carry anything else.

There's so much different silicon now that it isn't really feasible to stock even a small portion of it in every mall anyway, so most anything you fix you'll have to order in parts for...

It would have been more reasonable when I was a kid (and they only stocked a whopping 3 transistors and zero fets then, too).

Though it requires active cables, which cost quite a bit more. So it might have a place for bleeding edge stuff, but not so much for economy.