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The electrically literate may find this somewhat simplified article redundant; or possibly amusing. They should check out Wikipedia for any gaps in their knowledge.

But I hope this will help those for whom Wikipedia is a bit too complicated and/or detailed.

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All cartoons from The New Yorker - 1925 to 2004

 

 

Think of water in a hosepipe

 

Electricity is a means of transporting energy from a source, like the wind, to a device you use to exploit that energy, like your electric toothbrush.

The usual way of explaining electricity is to use the simile of the flow of water in a pipe (a current of water).  We are all familiar with a hose pipe.  Its pressure is analogous to the voltage; and the flow of water is analogous to the current. 

 

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The author - almost two - learning about currents and voltage

 

The work that can be done in an hour, for example if you use the jet to spin a bicycle wheel or push leaves along a path, is the pressure (like Volts) times the current (like Amps) for an hour. 

You won’t be able to squirt the water from your hose far if there is no pressure or if there is no water.  You need both.  If the pressure falls the water ceases to flow.

It’s the same with a stream (current) of electricity making its way down a conductor; for example a wire. The electrical force acting on an electrical current provides the power to do work.

Most quantities in modern physics are named after an early natural philosopher or inventor.  If we had let tradition do it, each would probably be related by some strange number, like the number of feet in a mile; or pounds in a ton.  But most new physical values use the decimal system (the rationalised MKS or SI units: meter, kilogram, second).

A Watt is a measure of Power; the instantaneous capacity to do work; named after James Watt. 

Under this system we define one Watt as equal to one Volt (electrical  force) multiplied by one Ampere (current); or Amp for short.  Read More...

Using this simple relationship you can easily calculate that 1000 Watts of power (one kilowatt) can be carried by a current of 4.17 amps at 240 volts (240 x 4.17 = 1000)

But the same power requires only 0.002 amps at 500,000 volts (0.002 x 500,000 = 1000).  So when you turn on an electric kettle or toaster it will draw around 4 amps in your home at 240V but only 0.002 amps in the very high voltage grid to bring it from the generator in the power station.

Power exerted for a period of time is called Energy.  Physicists measure energy in Joules (1 J= 1Watt acting for 1 second).  But to get to a smaller working number electricity companies like to measure energy in kilowatt hours (1 kWh =  3,600 kJ = a thousand Watts acting for the seconds in one hour) 

When your bill comes, you get charged for the Energy, the number of kWh* you used, not Power (kW).

 

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*Terminology:  1000 Wh = 1 killowatt hour (kWh); 1000 kWh=1 megawatt hour (MWh); 1000 MWh = 1 gigawat hour (GWH), 1000 GWH = 1 terawatt hour (TWh).

 

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Travel

China

 

 

I first visited China in November 1986.  I was representing the New South Wales Government on a multinational mission to our Sister State Guangdong.  My photo taken for the trip is still in the State archive [click here].  The theme was regional and small business development.  The group heard presentations from Chinese bureaucrats and visited a number of factories in rural and industrial areas in Southern China.  It was clear then that China was developing at a very fast rate economically. 

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Fiction, Recollections & News

The McKie Family

 

 

 

Introduction

 

 

This is the story of the McKie family down a path through the gardens of the past that led to where I'm standing.  Other paths converged and merged as the McKies met and wed and bred.  Where possible I've glimpsed backwards up those paths as far as records would allow. 

The setting is Newcastle upon Tyne in northeast England and my path winds through a time when the gardens there flowered with exotic blooms and their seeds and nectar changed the entire world.  This was the blossoming of the late industrial and early scientific revolution and it flowered most brilliantly in Newcastle.

I've been to trace a couple of lines of ancestry back six generations to around the turn of the 19th century. Six generations ago, around the turn of the century, lived sixty-four individuals who each contributed a little less 1.6% of their genome to me, half of them on my mother's side and half on my father's.  Yet I can't name half a dozen of them.  But I do know one was called McKie.  So this is about his descendents; and the path they took; and some things a few of them contributed to Newcastle's fortunes; and who they met on the way.

In six generations, unless there is duplication due to copulating cousins, we all have 126 ancestors.  Over half of mine remain obscure to me but I know the majority had one thing in common, they lived in or around Newcastle upon Tyne.  Thus they contributed to the prosperity, fertility and skill of that blossoming town during the century and a half when the garden there was at its most fecund. So it's also a tale of one city.

My mother's family is the subject of a separate article on this website. 

 

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Opinions and Philosophy

Whither Peak Oil

 

 

The following paper was written back in 2007.  Since that time the Global Financial Crisis (GFC) struck and oil prices have not risen as projected.  But we are now hearing about peak oil again and there have been two programmes on radio and TV in the last fortnight floating the prospect of peak oil again. 

At the end of 2006 the documentary film A Crude Awakening warned that peak oil, ‘the point in time when the maximum rate of petroleum production is reached, after which the rate of production enters its terminal decline’, is at hand. 

Read more ...

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