posted May 31, 2000 05:42 AM         

Electric current is a flowing motion of charged particles. The words "Electric Current" mean the same as "charge flow."
Electric current is a very slow flow of charges. On the other hand, electric energy is made of fields and it moves VERY
rapidly. Electric energy moves at a different speed than electric current, so obviously they are two different things. Unless
we realize this, we won't understand how circuits work. Indeed, we will have little basic grasp of electrical science.

In an electric circuit, the path of the electric charges is circular, while the path of the energy is not. A battery can send
electric energy to a light bulb, and the bulb changes electrical energy into light. The energy does NOT flow back to the
battery again. At the same time, the electric current is a circular flow, and the charges flow through the light bulb filament
and none are lost.

Electric energy can flow in a direction opposite to that of the electric current. In a single wire, electric energy can even
move continuously forward while the direction of the electric current is alternating back and forth at high frequency.

Here's one way to clarify the muddled concepts: if electric current is like a flow of air inside a pipe, then electrical energy is
like sound waves in the pipe, and electrons are like the air molecules. Sound can travel through a pipe if the pipe is full of air
molecules, and electrical energy can flow along a wire because the wire is full of movable charges. Sound moves much
faster than wind, correct? And electrical energy moves much faster than electric current for much the same reason. Air in a
pipe can flow fast or slow, while sound waves always move at the same very high speed. Charges in a wire can flow fast or
slow, while electrical energy always flows along the wire at the same incredibly high speed. Whenever sound is flowing
through a pipe, the air molecules in that pipe are vibrating back and forth. When waves of AC electrical energy are flowing
along a wire, the electrons in that wire are vibrating back and forth 60 times per second. What if we were all taught that
sound and wind are the same thing? This would prevent us from understanding wind or sound. Books teach us that electric
currents are a flow of energy, and it prevents us from understanding both current and energy flow. Be careful, since my
description of the above pipes are just an analogy, and sound waves aren't *exactly* like electrical energy. For example,
sound can flow inside an air-filled tube, while electrical energy always flows in the space outside of the wires, and does not
travel along within the metal wires. However, electrical energy is coupled with compression waves in the electrons of the
wire surface.

Electric energy is composed of electric and magnetic fields, and it exists in the space surrounding the wires. Electric energy
is very similar to radio waves, but it is very low in frequency. Electric CHARGE is very different than the energy. The
charge-flow (current) is a flowing motion usually of electrons, and electrons are material particles, not energy particles. And
it's not always a flow of electrons: when electric current exists inside an electrolyte (in batteries, salt water, the earth, or in
your flesh) it is a flow of charged atoms called ions, so there is no denying that it is a flow of material. Current is a
matter-flow, not an energy flow.

Is it important for us to realize that wind is not sound? Obviously. School books would cause harm if they taught us that
wind is sound. And if we want to understand circuits, we need a clear view of electric charge flow, and of electric energy
flow. We need to be totally certain that they are two different things, and our textbooks teach us the exact opposite!

Electric currents in copper wires are a flow of electrons, but these electrons are not supplied by batteries. They come from
the copper atoms in the wire. The electrons were already in the circuit before the battery was connected. They were even
there before the copper was mined and made into wires! Batteries and generators do not create these electrons, they
merely pump them, and the electrons are like a pre-existing fluid that is always found within all wires. In order to understand
electric circuits, we must imagine that all the wires are pre-filled with a sort of "liquid electricity."

To clarify this, get rid of the battery. Instead, use a hand-cranked generator as your power supply. Ask yourself exactly
where the "electricity" comes from when a generator powers a light bulb. A generator takes electrons in from one terminal
and simultaneously spits them out the other one. At the same time, the generator pushes electrons through the moving coil of
wire inside itself and through the rest of the circuit. Unlike a battery-powered circuit, all we have is wires. Where is the
source of "electricity?" When we include the generator in the circuit, we find that the circuit is a continuous closed loop of
wire, and we can find no original source of the "electricity." A generator or battery is like a closed-loop pump, but it does
not supply the substance being pumped. But we were all taught that "batteries and generators create current electricity."
This phrase forms a serious conceptual stumbling block (at least it did for me!) To fix it, change the statement to read like
this instead: "batteries and generators cause electric charge to flow." To complete the picture, add this: all conductors are
full of movable charge.

A battery or generator is like your heart: it moves blood, but it does not create blood. When a generator stops, or when the
metal circuit is opened, all the electrons stop where they are, and the wires remain filled with electric charges. But this isn't
unexpected, because the wires were full of vast quantities of charge in the first place.

Most textbooks discuss a substance/energy called "current". They constantly talk about flows of current. However, here is
a pointed question: WHAT FLOWS IN RIVERS: Water, or "current?" If I fill a bucket from the faucet, is my bucket full of
"current?" No! Another question: what if the English language had no word for "water", but we called it "current" instead?
What if we believed that rivers were full of "current" which flowed? Wouldn't people tend to aquire many serious
misconceptions about the nature of water? (They might imagine that it vanishes whenever it stops flowing, since a halted
current is... nothing!)

As far as elementary textbooks are concerned, we have no word for the stuff that flows inside of wires. The stuff, when it
flows, is properly called "an electrical current", but when the stuff *stops* flowing, what do we call it? Refer to advanced
physics texts, and there we find its correct name: charge. An electric current is a FLOW OF CHARGE. Yet the K-6
books never mention this. Instead they say that "current" flows. Worse, most of them say that "current electricity" flows in
wires. To this I say, "Is there a special kind of water called 'current water?'" The answer obviously is NO. The same
answer applies to electricity: electricity can flow and electricity can stop, and a flow of electricity (or charge) is called an
Electric Current, but there is no such thing as "current" electricity.

The word "charge" has more than one meaning, and the meanings contradict each other. The "charge" in a battery is energy
(chemical energy), while the "charge" that flows in wires is electron particles. The term "charge" refers to several different
things: to net-charge, to quantities of charged particles, and to "charges" of energy. If you are not very careful while using
the word "charge" in teaching, you might be spreading misconceptions.

For example, even when metals are totally neutral, they contain vast quantities of movable electrons. So, should we say that
they contain zero charge because they are neutral? Or, should we say that they contain a very large amount of electric
charge, because they are filled with electrons? Don't answer yet, because your answer might be inconsistent with how we
describe capacitors (further below.)

Another: if I place an electron and a proton together, do I have twice as much charge as before, or do I have a neutral
hydrogen atom with no charge at all? What I DO have is confusion. Misuse of "charge" makes descriptions of electric
circuits seem complex and abstract, when the explanations are really just wrong.

Another: electric currents in wires are actually a motion of "neutralized" charge, where every electron has a proton nearby.
If we teach that a wire is uncharged, and we ALSO teach that electric current is a flow of charge, how can anyone make
sense of a situation where a wire has no charge at all, yet contains an enormous flow of charge? We could say "Oh, but
electric currents are usually a flow of Uncharged Charge." WHAT? What would a student make of THAT statement? Can
you see the problems that arise because of the word "charge?"

Another one: as you "charge" a battery, you cause an electric current to appear in the electrolyte, and this motion of electric
charges causes chemical reactions to occur upon the surfaces of the battery's plates. Chemical "fuel" accumulates, but
charge does not: the charges flow into (or out of) the surfaces of the plates and do not accumulate there. Chemical energy is
stored in the battery, but electrical charge is not. When a battery is being "discharged", it's chemical fuel drives a process
which pumps charge through the battery. The fuel will eventually be exhausted, but the total electric charge within the
battery will never change!

Here's a way to imagine the process: a battery is like a spring-driven "wind up" water pump. Send water backwards
through this pump, and you wind up the spring. Then, provide a pathway between the inlet and the outlet of the pump, and
the spring-motor will pump the water in a circle. But now think for a moment: the water is the charge, yet our wind-up
pump does not store water! When we "charge" our wind-up pump, we send the charge (water) THROUGH THE PUMP,
and this stores energy by winding up the spring. Same with a battery: to "charge" a battery, we send electrical charges
THROUGH THE BATTERY and back out again. This causes the chemicals on the battery plates to store energy, like
winding up the spring in our spring-powered water pump. See how "charging" and "charges" can create a horrible mess of
misunderstandings? When this mess gets into the textbooks, and educators start teaching it to kids, the kids end up
believing that Electricity is too complicated for them to understand. Yet the fault does not lie with the students!!!!

Another one: if you "charge" a capacitor, you move charges from one plate to the other, and the number of charges within
the device as a whole do not change. Or from an engineer's perspective, you drive charge THROUGH the capacitor,
which causes potential across the plates to rise. But capacitors have exactly the same total charge within them whether they
are "charged" or not! Whenever we take an electron from one plate, we put an electron onto the other plate. When we
speak of "charging" capacitors, we've suddenly stopped talking about charge, and started talking about electrical energy. A
"charged" capacitor has quite a bit more energy than an "uncharged" one (but exactly the same net-charge, and the same
quantity of + and - particles inside it.) This basic concept is very important in understanding simple circuitry, yet it is rarely
taught. The misleading term "charge" stands in the way of understanding. I suspect that students are not the only ones being
misled. Many teachers misunderstand simple physics, and they believe that the purpose of a capacitor is to store electric
charge.

Think like this: both capacitors and inductors (coils) store ENERGY, and neither one stores charge. Yet electric charge is
the medium of energy storage in both coils and capacitors. In capacitors, energy is stored in the form of "stretched charge",
or potential energy, while coils store energy in the form of moving charge which contains kinetic energy. However, we don't
put any charge into a capacitor when we "charge" it, any more than we put charge into a superconductor ring-inductor
when we give the ring a "charge" of electromagnetic energy.

this info can be very helpful, if you are having problems with a battery, like it not being strong enough to light devices by the time it travels down the wire, then buy thinner wire. I have over 100 feet of wire
and only use 2-9volts to light model rockets.
of course there is always aluminum wire which is less dense making it real easy on those electrons. and of course I didnt sit hear and type all this crap, for more info check out this site http://www.eskimo.com/~billb/miscon/elect.htm l

posted May 31, 2000 11:16 AM            

A nine volt would only be able to charge a 9volt capacitor, any higher and you'll need an inverter. Camera caps are usually around 330v. Yet they charge with either using 1x or 2x 1.5v cells. Inside it has an inverter circuit which cranks up to voltage so it can charge the capacitors.