Thursday, December 9, 2010
Engineer (part 3)
You do have a generator; don’t you?
A generator takes motion and turns it into electricity. This is the exact opposite of a motor, which takes electricity and turns it into motion. DC motors are designed in such a way that they can also be used as DC generators. (Due to their design, AC motors cannot be used as generators; so let’s focus on DC)
DC is the electricity coming from the batteries in your car, flashlights, or walkie-talkies. THIS IS ALSO THE ELECTRICITY PRODUCED BY THE BAGHDAD BATTERY.
Ok, let’s get a very basic understanding of electricity.
Electricity flows through wire in a manner not unlike water or air flowing through pipes. You could make a fair comparison between a water pump and a generator. The water pump pushes water, and the generator pushes electricity. If you contain the water and focus it toward a water wheel, you can put it to work moving things. The same thing happens in a motor. The electricity is directed toward a coil, and there it is put to work moving things. Push = voltage.
A battery can be compared to a tire. A tire full of air will release that air to push the pressure gauge (meter) when you check your tire pressure. This is similar to someone checking the ‘voltage’ of your battery with a volt meter.
The speed at which the water flows through the hose can be compared to the speed at which electricity flows through the wire. Flow = amps.
First, lets’ talk voltage.
A regular ‘AA” battery will measure out to 1.5 volts. This is a 1 cell battery.
A regular 9 volt battery contains six 1 cell batteries that are wired together. Each cell only produces 1.5 volts, but when wired together the voltage adds up.
When you combine 1 steel bolt with 1 copper pipe in 1 container of water, (wine, grape juice, vinegar, etc. any liquid will work, and from here on out we will call this liquid- electrolyte) (as in the Baghdad battery); you have 1 ‘cell’. (at this point you have created your own ‘AA’ battery)
If you combine a few of these ‘cells’ you can increase the total output. Just like in the 9 volt.
A series arrangement will cause the voltages to add together. This is how you connect these cells in ‘series’.
If you think of the copper pipe as the negative side and the steel bolt as the positive, you could connect 6 cells with a wire from the bolt in cell one to the copper pipe of cell 2 and then from the bolt of cell 2 to the copper pipe of cell 3, and so on. Be sure to leave the wire coming off of the bolt of cell 6 and the wire from the copper pipe of cell 1, as the wires you use as terminals of your ‘homemade battery’. You can connect as many of these cells as you wish as long as the first negative wire and the last positive wire are used as your terminals.
Now, let’s look at amps.
A parallel arrangement will cause the amps to add together. This is how you connect these cells in parallel.
If you think of the copper pipes as the negative side and the steel bolt as the positive, you could stretch a wire to touch all of the copper pipes and then stretch a second wire to touch all of the bolts. Keep the ends of these 2 wires separate. A car battery has only 6 cells, but they are arranged in parallel. Because of the arrangement and the materials used, it is capable of producing 650 amps! Less than 1 can kill you.
The ‘magic’ at play here only works if the copper pipes and the bolts are not touching, but are close to each other. It is also imperative that they are separated by the water or wine. Lastly the ‘cells’ are individual. They each contain their very own copper tube, steel bolt, and container of electrolyte. The copper tube itself could hold the water.
Remember, in your list of supplies, there was a DC motor. If you hook a battery up to it, it will run. This is the electricity flowing from the battery to the motor. If you want to use the DC motor as a generator to charge the battery you have to make the electricity flow from the motor to the battery.
This is done through the use of a rectifier.
A rectifier will only allow electricity to flow in one direction, so if you connect it to one wire between your motor and your battery, you only allow flow one way. If you connect it the right way, you could simply turn the shaft of the motor and recharge your battery. Some people attach blades and use wind to turn the shaft.
I believe a bicycle could be put to use for this.
You know what? Building your own battery is a good thing to know how to do. However, if you are putting together a kit that could be used to help you survive for a while until you learn how to live off the land; maybe a real car battery would be a good investment. If you end up with several car batteries; they could be wired in series or parallel also as a source of power.
Now, what good is it to have electricity when you have no appliances to use it?
You will at some point have to go out and return with some sort of supplies. Junkyards are great resources for the engineer, and if you have the means to power lights you provide safety (or at least the appearance of it). Some devices will require AC voltage. The AC inverter changes DC (your battery) to AC (your light fixture).
Lawn mower engines are useful. So are bed frames, tires, coffee grounds, cans… Man, we could go all day! Anything that can be carried can be useful. It can also hurt the group, so choose wisely. The most important thing is stealth and resourcefulness. Not just in traveling or looting but also in social situations. Don’t dismiss the rules.