Electrical question

[Huge]

Safer? With half the voltage (and hence twice the current), aluminium wiring, wooden houses and volunteer fire brigades?

[Terry Casey]

Yes - semiconductors self destruct faster than fuses!

I don't ever recall problems with valved equipment protected by quick blow fuses, though.

[The Natural Philosopher]

I can. Marshall tops would always blow the 100mA HT fuse. 140 dB of rock guitar is more than they could stand.

Roadies all used tinfoil from packets of gas, or replaced with 500mA...

[Dave Plowman (News)]

Why don't they make fuses made out of semi-conductors, then? ;-)

[ARW]

They also have to use a "hot wire" at 240V (line to line) to power up heavy duty stuff.

[Johnny B Good]

One early definition of a transistor (c50ya) was. "A ten dollar device designed to protect a ten cent fuse."

Thermionic valves (vacuum tubes) are pretty robust devices. even if the anode rail is hit by a massive voltage spike, enough to cause a flash- over and melt a hole in the anode plate, they'll often continue to function with no perceivable drop in performance (unless it's a *really big* hole in the anode plate).

[Johnny B Good]

Polyfuses, the self healing types used to protect the 5 volt rail feeding the keyboard/mouse/usb1 and 2 ports on motherboards are a form of semiconductor fuse.

[Fredxx]

Because many semiconductors tend to short or fail in such a way to offer little or no protection.

[Huge]

Well, 220V, anyway. With different plugs and sockets to prevent people plugging 110V stuff into 220V outlets.

And I forgot all about wire nuts.

The last time I had this argument with a septic, I tried to find some statistics about the relative rates of house fires vs. electrocutions in the respective countries, but couldn't find anything conclusive. But my attitude about American electrics was mostly formed from doing odd jobs on my Mum's house (she lives in Pennsylvania) after my Dad died and before she moved in a retirement community, where they have maintenance men.

[Fredxx]

Any high power appliance will still have 220V, or sometimes 208V (across

2 of the 3 phases).

A lot of high power stuff, such as washing machines, is directly plumbed in though plug and sockets are becoming the norm.

They tend to have transformers closer to the dwelling than us. Being

60Hz it makes their transformers both smaller and more efficient.

I blame the Germans for standardising on 50Hz, one thing they got wrong.

[The Nomad]

If they'd gone for 100Hz then it would not affect heart muscle and so much less likely to kill.

Avpx

[Cursitor Doom]

There is also the small matter of the price of semiconductors vs. a bit of thin wire!

[Cursitor Doom]

There's a book out somewhere (been meaning to get a copy for years) where the author explains how you can make your own valves. Think it's called 'desert island electronics' or 'post-armageddon radio' or something like that. PW list it in their adverts section quite regularly.

[Bob Eager]

And heavier cables. I'm not a power engineer, but either twice the number of cables or (I believe) more than twice the cross sectional area for one cable.

[Max Demian]

Why not make your own semiconductors? After all, galena is naturally occurring.

[Terry Casey]

Yes, but that's the other way round!

Bill was saying that the fuses often don't protect the equipment.

Marshall obviously under estimated the fuse rating.

I once repaired a Vox AC 30 where a section of the earth busbar had vapourised as a result of being connected to a German echo chamber they'd lent to somebody who'd removed the

13A plug.

Before EU harmonised colours were introduced, the German earth wire was bright red.

When they ran out of 13A fuses, the trusty foil from a ciggy packet had been used.

[Tim Watts]

Some YT video I saw the other day claimed it has been re standardised to

120V/240V

Wikipedia seems to agree:

And an interesting variant of 208V (phase-phase on a 120V 3 phase supply) was also noted in the same video and it was suggested that some people actually used that as their "240V" supply with the expected problems.

I think that same video used those - IIRC I was watching some Texans wire up a load of solar panels and an inverter.

Do they not have armoured cable over there? These dudes were burying their version of T+E about 5" into the dirt!

[Cursitor Doom]

There's no point making your own semis that I can see. This isn't the

1950s any more and those things are now cheap as chips.

[Cursitor Doom]

Back in the 1960s I used to use milk bottle tops; they were a bit more substantial.

[Johnny B Good]

There's a nice 4 part series about making a Lee de Forest Audion triode valve (vacuum tube) by Ron Soyland on YouTube which describes all of the construction steps in great detail.

takes you to the first episode.