Ok…its been aeons since I have done a history post…and even longer since a physics post, so why not do 2 in 1 and do both together! Its time to do a history of power transmission!
The Main Characters Involved
Once upon a time, there lived a magician. Almost deaf and self educated, he played a major part in the history of Industry. He was known for perseverance, and for a factory that burnt down as well. His name: Thomas Alva Edison, more colourfully known as”The Wizard of Menlo Park”
The second chap in this was rather less colourful. He was known for an obsession with Railway safety and his major contribution prior to his adventures with electricity were his amazing invention of brakes for railways. Even today, the air brakes that are used today are a product of George Westinghouse, who shall be called “Moneybags“
The third chap here is as much of a character as Mr. Edison. Rather than Gandalf, it was he who was first called “Wizard of the West”. A mathematician and an inventor, he was a former employee of the Menlo Park wizard. After some harsh words were said on both sides, he quit to fight his battle for efficiency and superior science. His name: Nicola Tesla.
The Technology:Sneak Peek
So what did these chaps fight about. It was no less than the way the new magic of the century, electricity would be transmitted. It was a battle between Alternating Current and Direct Current. The battle between AC/DC.
On the DC camp stood the reigning champion, and knight of the American derring do spirit, T A Edison.
On the side of AC, the challengers were an embittered Nicola Tesla and Westinghouse.
The Rivalry Begins:
Nicola Tesla was originally a humble scientist, working under the heel of an acknowledged genius in Edison. But Tesla was also a super mathematician type dude, while the more prosaic Edison was merely a brute force experimenter. Tesla was a huge fan of the newfangled Alternating Current that promised revolutionary change.
Edison though was not entirely for things that used imaginary numbers and wave equations. In his opinion, if you had to use things like root of -1, you were off your rocker a wee bit. But being a fairly loud-mouthed guy, he proclaimed to Tesla that if he ever got an AC motor working, he would get a bonus of $50,000 (no mean sum at the time).
Tesla of course was truly fascinated by that grand sum. He spent days working, and nights calculating under the patented light bulb of Edison and Swan’s GE. Finally, after months and years of toil, he came up with an awesome AC generator that works. He goes smiling proudly to Edison, and shows it to him.
Unfortunately for him, Edison was a bit deaf. He claimed that he never heard himself say such a ridiculous thing in his life, and laughed at Tesla. It might have also been exacerbated by the fact that Edison never really understood the principles by which AC power was generated and transmitted as well.
Tesla decided that this would not do, and ran away in a huff, threatening to do Edison in someday. Thus a magnificent rivalry was born.
Enter Westinghouse
George Westinghouse was no mean inventor himself. With patents pouring in for railway safety brakes, and a machinist par excellence, he was an inventor in the mould of an Edison. Unlike Edison though, he was also a big believer in the utility of calculation and mathematics in invention. Spotting Tesla out of work, and digging ditches in New York, he realized that he had an ideal employee on his hands.
Back to Technology– The Numbers
Edison’s DC current is comparatively easy to understand, and is based on middle school physics. Power transmitted is given by VI, where V= Voltage and I= current. However, power loss is given by current squared multiplied by resistance of the wire. At low voltages, the power loss is rather large, unless the diameter of the copper wire is made terribly large. However, high voltages were deemed to be unsafe, and Edison was using DC voltages of about 110 Volts.
As a result, power losses made it impractical for Edison to transport electricity across large distances. The resistance would have killed him. Edison was nothing if not a canny businessman though. He started making tonnes of generators that generated electricity locally, and started selling them. This ensured regular sales of GE generators, because the effective radius of even the largest DC generators at 110 watts was a couple of miles.
Now, AC is a whole different ball game. The power loss is practically the same at a given voltage (we won’t go into the formula. Like Edison, I am not a formula guy!). However, AC has the huge advantage that it can be “stepped up” and “stepped down”
Enter the Transformer
The transformer was the device that made AC a great option. A transformer is a very simple device that converts electric voltage up or down. By winding more wires one way or another, you could generate power at one voltage, then transform the voltage up. From basic electricity we can say this: V1I1=V2I2. When Voltage goes up, the current carried by the wire goes down. Power loss is calculated as I*I*R. Now, when Voltage goes up to 22000 or 40000 Volts, the current drops dramatically. Now, I*I it becomes very small, and power loss is lessened dramatically. Near the end consumer a transformer is used again to drop the voltage to a usable level.
Of course, the catch was that a transformer could only be used in AC. It could not be used (for various reasons) in DC format. The various reasons include esoteric terms such as inductance and flux, but this is not a post about physics, but history.
Return to the Battle: Publicity time
Westinghouse and Nikola Tesla began to make an AC Generator that would unshackle the world from Edison’s DC generators. But it was hard toil. Firstly, AC current keeps cycling up and down, which in lightbulbs would mean a flickering of light bulbs as current cycled between two extreme values.
Then there was another problem. Cyclic voltage tends to do something nasty. The shifting voltages cause the heart to change to an irregular rhythm, which tends to lead to a quick trip to a nearby graveyard. Low Voltage DC does not cause any such problems. And Edison knew exactly how to exploit this unfortunate “feature”
Edison launched a campaign which attempted to prove how dangerous AC was. Initially, he started by electrocuting cats and rats. Soon, he progressed to man’s best friend. Size of course matters…he continued by going after horses and then cattle. In a fit of extravagance, he completed this with a finale where he finished off an elephant with AC.
But this was not enough. The AC Camp led by Westinghouse was still winning. Now Edison was getting desperate. First he tried to replace the term electrocute with the phrase “to Westinghouse someone”. That did not work out too well though. It never did catch on. Although Edison was against the death penalty, his business interests now dictated he needed to do something radical. Size did not seem to matter in the war. Now it was time to change tack. He began a secret product called the “electric chair”. Soon an instrument of death was ready, and an unfortunate convict was ready as a test subject.
As a deterrent to crime, it was a staggering success. The dashed thing failed on the first attempt, merely leaving the guy with severe injuries rather than killing him. After several tries, he was finally put out of his misery, and it was described by one appalled journalist as, “It would have been kinder to kill him with an axe!”
Unfortunately, as a proof of concept, the electric chair was not quite an unqualified success. The tide was beginning to turn in the favour of the Westinghouse camp. Soon, the death knell for Edison’s generators was about to sound.
Niagara Falls
The Niagara falls were the holy grail for power guys. Here was a mountain of water falling a few hundred feet, which had the potential to generate enough power for the whole of the North-east USA (at the time). The catch? It was just too far away. Any chap who generated power in the Edison way could not actually transmit the damned thing without losses that crippled it to unusability. Westinghouse lobbied long and hard, and finally got the permission to generate power in AC so that it could be transmitted easily. And since Edison’s GE was too powerful to be ignored, it got the contract to transmit this electricity. With this, Edison ended his opposition to AC power, and the war of the Currents was won by Westinghouse and Nicola Tesla.
Epilogue
Tesla was known as the wizard of the west. There is little doubt that he was at least partly responsible for the way the 20th century became the century of electricity. However, his rivalry with Edison was not tempered with time, and it is curious that neither Edison nor Tesla ever won the coveted Nobel prize. Rumours still abound that it was jointly offered to the two of them, but Tesla refused to ever accept a prize alongside Edison. Later in life, he began to make futuristic predictions about wireless electricity, but these were never considered practical, so he was slowly shunted away from mainstream science. But he forever gloated about his joy at defeating Edison.
