War of the Currents

[Pelado]

What do you engineering types think about the ultimate triumph of the direct current advocated by Edison as portrayed in this article:

AC distribution of electricity has reigned supreme for more than 100 years. But a quiet insurrection is taking place in our midst. Our computers, machines, LEDs and electric cars all run on DC. And at the extremes of high power – distributing electricity thousands of kilometres from one region to the other – engineers have discovered that the losses from a million-volt transmission line are lower if it carries DC current rather than AC current.

Once again, the transformer is the secret weapon, but this time operating on DC. These new transformers take the form of electronic circuits that convert DC currents up and down the spectrum from a few volts to a million or more. Lighter and smaller than traditional ones, DC transformers make it easier to integrate wind and solar electricity into the grid, and they reduce the likelihood of failures cascading from one electricity generation region to another.

https://cosmosmagazine.com/technolog...ake-a-comeback

[Uncle Ted]

Tesla was an interesting guy and he invented a lot of interesting things... but not the "death ray":

The Time Nikola Tesla Paid for His Hotel Room With a "Death Ray"

Nikola Tesla was, of course, a vastly accomplished scientist and inventor. His inventions include the Tesla coil and electric oscillators, and he also developed technologies that were eventually found in X-rays, the radio, and remote controls.

One thing he didn’t invent: A death ray. But try telling that to the Governor Clinton Hotel.

Tesla had financial problems later in life, and in 1915, his famous Wardenclyffe tower plant was sold to help pay off his $20,000 debt at the Waldorf-Astoria. By the 1930s, Tesla had again racked up a sizable bill at a hotel, this time the Governor Clinton Hotel in Manhattan. He couldn’t afford the payment, so instead, Tesla offered the management something priceless: one of his inventions. He told them the device—which he referred to as a death beam, not a death ray—was extremely dangerous, and could detonate if someone opened it without taking the proper precautions.

When Tesla died in 1943, an MIT scientist working for the National Defense Research Committee was sent to Tesla’s hotel room/lab to retrieve the potentially deadly weapon. Accompanied by the office of Naval Intelligence, John O. Trump later wrote in his FBI report that he took time to reflect upon his life before he opened the container.

He shouldn’t have bothered.

The only thing the wooden chest contained was a “multidecade resistance box of the type used for a Wheatstone bridge resistance measurements—a common standard item found in every electric laboratory before the turn of the century!”

In other words, Tesla threw some common electrical components in a fancy-looking box and convinced everyone it was a "death beam" worth $10,000. Tesla’s good friend, Mark Twain, would have been proud.

http://mentalfloss.com/article/65857/time-nikola-tesla-paid-his-hotel-room-death-ray

The Current War looks like a good show.

[Scott R Nelson]

This is the first time that I've seen anybody claim that DC current can be sent long distances with fewer losses than AC current. That article had no useful information at all on the subject. Until I see an article on this subject in https://arstechnica.com/ I won't believe it.

Yes, DC is used in computers, but even in the old days of higher voltages it was never more than +12 or -12 volts. Most of it was 5 volts and now it's generally around 1.5 volts. And it has absolutely nothing to do with power distribution over long distances.

The main reason Tesla and Westinghouse beat Edison is because DC current didn't travel well more than a mile or two. If there were a way to transmit DC efficiently, I would have expected somebody to have figured that out during the last 100 years or so. Call me a skeptic on this one.