BBC: Shocking facts about electricity

What do you know about AC DC?

You mean the Australian rock'n'roll band? Well, their 1979 hit 'Highway to Hell' stayed at No.1 for eleven weeks...

No, no, no- not that AC DC, Georgina! I'm not talking rock music here, I'm talking electrical currents- alternating current- AC, and direct current- DC, the two ways in which electricity flows. 

Oh, I see. No, I don't know anything about that ACDC!

Well, don't worry because in today's programme we'll be finding out some quirky facts about electricity- how it differs across the world and why some countries have more complicated eletrical systems than others. 

Hmmm, it could be. Of course, electricity itself doesn't change from country to country. 

No. It's an invisible, natural force at work in everything from lightning storms to the electrical sparks firing our brains. 

But although it happens naturally, one scientist was credited with discovering electricity. Who? That's my quiz question- who discovered electritidy? Was it:

a) Thomas Edison   b) Alexander Graham Bell   or c) Benjamin Franklin?

I'm not a qualified electrician myself, Neil, but I'll say c) Benjamin Franklin. 

OK. Well one person who definitely is a qualified electrician is BBC presenter Gareth Mitchell. So, when BBC Radio 4's 'Science Stories' sent him to meet electricity expert Keith Bell, the conversation was, shall we say, sparky.

Standard frequency in the US is 60 hertz, actually I think in the US on the mainland US, main continent, there are three different synchronous areas. So although it's around 60 hertz, at any moment in time these three different areas, because they're not connected to each other, will be going at a slightly different frequency. There are bigger differences elsewhere. So in Japan for example, I think one of the main island is at 60 hertz and the other half of Japan is at 50 hertz. 

That's a bit of a pickle!

Geneally speaking, frequency means how often something repeats. In the case of electrical currents, frequency is the number of times an electrical wave repeats a positive-to-negative cycle. 

It's measured in hertz(HZ). In the US power is at 60 hertz and in teh UK it's aroudn 50 hertz. 

So the US and UK are not in the same synchronous area- not occuring together at the same time and rate, or in this case, frequency. 

Which means that to safely use a British electrical device in America I need to convert the power supply. If not it won't work or even worse, it could break. 

And a broken laptop could leave you in a bit of a pickle- an informal expression meaning a difficulat situation with no obvious answer. Here's Gareth and Keith again talking about more differences. 

I'm pretty sure when I go to the United Sates, my electric toothbrush doesn't charge up at 60 hertz- 110 volts, but my laptop still works. Maybe you have no comment, Keith, but I'm just saying...one of these anomalies that I seem to have found. 

So, I'm not sure about the electric toothbrush but I know a lot of our power supplies for laptops and stuff are solid state, you know- they've got electronics in that do all the conversion for you, so basically it ends up with a DC supply into the machine itself. So, there's a little converter in there and it's designed it doesn't care what frequency the AC input is. 

Gareth noticed that in the United States his toothbrush doesn't always fully charge up- get the power needed to make it work.