What comes out of your home's power wall socket is not what anything in your stereo system needs. In fact, what comes out of your home's wall socket is the wrong thing for 99% of everything in your home. Certainly there are few things that like it: washing machines, refrigerators and an electric oven, but for the most part what we get isn't what we want.
Which begs the question of why don't we get what we want and need out of our home's wall power? The answer goes back to the beginnings of the industrial revolution and the battle between two geniuses: Thomas Edison and Nikola Tesla.
Let's start by understanding what it is we get (that we don't want) and what it is that we want (but don't get). What we get is AC power - and what we want is DC power. 99% of everything you plug into the wall must convert AC to DC before it can be used.
Imagine for a moment the size of the power grid in the United States - of which there are 3 (east, west and Texas) and the thousands of millions of devices that use that power. In each case power must be converted from AC to DC using inefficient methods and losing 10 to 30 percent of available power in the process.
Let's just round it down and say that 15% of the power in the world is lost because we have to convert AC to DC. That's a lot of power to spend on this process, so why go through it? The simple answer is that the amount we would lose delivering the power to your home in final DC form is greater than what we lose converting AC to DC. It is more efficient to use AC to send power long distances and that's where we start our story.
Most of us know Thomas Edison as the guy who invented the electric light bulb and the phonograph. The fact is he invented neither; instead his inventions took the work of others and made them practical to manufacture and use. Edison was a brilliant businessman and had a genius for making things work and turning them into industries. He changed our culture perhaps more than anyone of his time.
After figuring out how to build the world's first practical light bulb, Edison set about to produce and sell light bulbs as fast as he could. He had one big problem, however, and that was providing electricity to operate the new bulbs. Without power the light bulb was pretty useless and people were just fine using gas lanterns. In fact, homes of that day weren't wired for electricity at all but instead were "wired" with plentiful gas for their lights. Convincing people to convert from gas lights to this new fangled light bulb was a real challenge.
Tomorrow how Edison started America's first power company.
