Monthly Archives: December 2015
Generators are enormously helpful in a wide variety of situations; it tends to be pleasant to have access to electricity, especially if you’ve moved to a place that’s off the grid and you already are roughing it to some extent. If you’ve ever wondered exactly how your handy generator powers your hair dryer, this article is for you.
A generator is a device that moves a magnet near a wire in such a way that it creates a steady flow of electrons. Exactly how it does that varies greatly among different models created during different time periods and can range from hand cranks and steam engines to nuclear fission, but regardless the basic principle remains the same: move electrons using a magnet.
If it’s difficult for you to imagine electrons being forced to move, try to think of a pump pushing water through a pipe. A generator does the same to electricity, but uses a magnet to push electrons, so to speak. It pushes a certain number of electrons by using a certain amount of pressure.
In the context of an electrical circuit, the number of electrons being moved is called the amperage or current, and it’s measured in amps. The “pressure” that dictates how hard the electrons are being pushed is called the voltage and is measured in volts. So to make use of these terms, a generator that spins at 1,000 rotations per minute might produce 1 amp at 6 volts. The 1 amp refers to how many electrons are moving (specifically, an amp implies that 6.24 X 10^18 electrons per second are moving through a wire). The 6 volts tell us the pressure behind these electrons.
The first electric generator was invented by British physicist and chemist Michael Faraday. His first generator was called the dynamo, and he also invented the first electric motor.
So how do the generators actually work? Well in Faraday’s case, coils of copper wire are made to rotate between the poles of a magnet, producing a steady current of electricity. The coils can rotate simply by use of a hand crank, but a more practical and effective way of generating electricity involves attaching the shaft of the generator to a turbine and then letting another energy source power the turbine. Falling water is often employed for this.
In fact, one of the first and largest energy-generating plants is powered by Niagara Falls. Engineers built a water intake near the bottom of the dam wall that forces water through a narrow channel called a penstock in which the turbine is stationed. The turbine is a huge propeller that is pushed by the force of the flowing water. Its spinning motion rotates the shaft of the generator and rotates the copper coils of the generator. This spinning of the copper coils within the circle of magnets produces electricity. This electricity is then carried to homes and businesses via power lines.
Other power plants rely on steam to spin the turbine of a generator; burning coal allows for the boiling of water and the generation of steam, so coal tends to fuel the creation of electricity. It’s also possible to create electricity by using controlled nuclear reactions to turn water into steam. This allows people to rely less on coal, but people tend to be frightened of nuclear power because of a few famous nuclear meltdowns.
With Potato Day right around the corner, you may be wondering what the heck kind of decorations you’re going to find this year when you already have spent all your time and money refurbishing your jet skis. Believe it or not, an obvious option may have been spudding right under your nose this entire time: the potato! Turn a potato into a light!
Quick overview of electric currents: an electric current is the movement of electrons from one atom to another in a conductor. A conductor is a substance that can conduct electricity. With that in mind, here’s what you have to do.
Find a potato and cut it in half. Get yourself some electrical wire and wrap the end around a galvanized nail. Galvanized nails are nails that have undergone a process which covers them with a zinc protective coating. This coating acts as an anode, meaning it’s a positively charged electrode by which electrons can leave a device. An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit like a semiconductor, an electrolyte, a vacuum or air. In this case, the zinc on our galvanized nail will be acting as an anode that allows for electrons to leave the nail and enter the potato’s electrolytes.
Get a second piece of wire and wrap it around a penny. The penny contains enough copper to act as a cathode, which is also an electrode. An anode is positive while a cathode is negative, so an anode attracts negative charge while a cathode attracts positive charge. Stick the penny into a hole in the potato.
Once you’ve got these two wires with either a penny or a nail at the end, stick the copper side into one half of the potato and the nail into another half. Don’t let the zinc and copper electrodes touch each other. If a wire connects the zinc nail and the copper penny, electrons will flow, but direct contact will just produce heat as opposed to electric current.
When you put the metal electrodes into the potato, it causes a reaction to occur that results in electric current. The potato acts as an electrolyte that facilitates the transport of the zinc and copper ions in the solution while keeping the electrodes apart physically. An electrolyte is a liquid or gel that contains ions and can be decomposed by electrolysis; it is a fluid that carries a charge or can produce an electrically conducting solution when dissolved in a polar solvent like water. When it’s put in water, an electolyte separates out into cations and anions, allowing for current to flow. The phosphoric acid of the potato is responsible for the electro-chemical reaction of zinc and copper.
Zinc is an active metal that reacts readily with acid to liberate electrons. The acid’s active ingredient is positively charged hydrogen, so a transfer of electrons occurs between the zinc and the acid. Hydrogen gas is produced and bubbles out around the electrodes. The reaction at the penny electrode depletes the electrons and attaches them to the hydrogen ions in the phosphoric acid.
Now if you attach both ends of the wire to a tiny LED light, it will light up!