Step 4: Amps

But wait, since voltage is “electrical pressure” then there must be a measurement of volume, shouldn’t there? Well there is, and the measure is called the Ampere (A). The ampere, or amp, is the volume of electrons that are flowing (current). The unit is equivalent to about 6,242,000,000,000,000,000 (an assload) electrons flowing past a point in one second. Different electrical appliances require different amperages, with the typical LED flashlight requiring 60 milliamps (0.06A), an iPod requiring about 400mA and a refrigerator requiring 10A. With more current more work can be done, since more electrons carry more energy than fewer electrons. As can be seen by this video of a roofing nail burning, when large currents flow quite a lot of "work" can be done.

Why is it that so many people think electricity flows from positive to negative?
<p>Have you ever wondered why the circuit symbol for a battery looks exactly the opposite as real cells do? The + has a broad stroke and the minus a short one. If you look at a A* battery (and button cells) you see that the minus is actually the broader part. Also the diode symbol suggests the &quot;wrong flow direction&quot;. So if even engineers that ought to know actually swap things, how could laymen understand it?</p>
It's all Ben Franklin's fault and his inability to determine the charge on an electron before labeling a bunch of stuff he didn't understand.
Basically BF noticed that items can have either two charges: if two objects had the same charge, they would repel each other, but if they were different, they attracted each other. <br> <br>He decided that this must be the result of an imbalance of some kind of electrical fluid on the charged objects. He took an object with a positive charge and figured that it had an excess of electrical fluid, and that it was &quot;positive&quot; with fluid, and the opposite for negatively charged objects. <br> <br>Since BF had no way of knowing that electrons are the charge-carriers, he wouldn't have been able to know that negatively charged objects are saturated with electrons. <br> <br>Remember that In BF's time, electrons hadn't been discovered. <br> <br>It's all arbitrary anyway, there's now way to absolutely determine a positive charge versus a negative.
because electricity flows from +5v to for example -5v.<br>Alot of people, like me, think of + and - like this: <br><br>positive = positive ammount of electrons in relation to protons (negative charge) <br><br>negative = negative ammount of electrons in relation to protons<br>(positive charge)<br><br>:)
That's a lot to read =( but thanks!
Idunno
Cool
You should stick a fork in the toaster, electricity is just a myth!
This instructable looks extremely informative, I must say. I still need to finish reading your exhaustively in-depth article on High Voltage, but this looks like it belongs in the Instructables Hall of Fame for informative articles.
Great guide- concise and informative. Please do a &quot;part 2&quot; on the difference between amps and amp-hours and make everyone read it :D<br> <br> Also maybe one for newsreaders and lazy journalists on why saying &quot;this power plant will produce enough electricity to power 4,000 homes a year&quot; is meaningless tosh and they should learn a little bit about electricity... if only...
great instructable! very nice pictures and videos! the visuals were rich and the writing was very nice and easy to understand! 5 stars!