understand in simple terms how Current and Voltage 'works'
You are basically correct when you say that Voltage is the pressure or force of the electrons.
That's a good way to put it in layman's terms.
You also need to remember that voltage is simply a potential, with a "direction" that is relative. Technically, the voltage has no direction at all. In many circuits, voltage is measured relative to ground.
Current, in layman's terms, is sort of the amount of electron flow.
The current can be compared to the amount of water in the pipe.
Current flows from negative to positive.
This is where people get confused. Conventional current flow says that current flows from positive to negative, but in reality, that's more of a description of the voltage "direction". Current does not flow (+) to (-), but if ground is assumed to be (-), then the voltage is (+).
I realize that is a little confusing, so I'm just going to rephrase it simply by telling you to ignore conventional current flow .
Absolutely wrong. Pressure is force/unit area. You have never heard of voltage measured in newtons/meter^2 or pascals, have you?
No wonder laymen are confused.
A potential of what? Isn't every direction relative? Voltage does not move. The energy density of the charge carriers (voltage) increases/decreases at different points in space, but that is not movement. In other words, density does not move. Charges and energy can move.
Rate, or amount of charge carrier movement/unit time would be a better definition for current.
No, a long pipe of the same diameter as a short pipe has more water in it than the short pipe does, yet the short pipe can have the same flow rate.
Only if the charge carriers are negative. In other materials other than metals, like ions in electrochemistry or PNP semiconductors, the charge carriers are positive and charge flows from positive to negative.
The conventional current/voltage concept is a mathematical artifice, not a physical description. Folks seem to have a hard time realizing that. The method does not get bogged down with what direction a particular carrier of a specific polarity moves. Real current does exist from positive to negative if the charge carrier is positive. But that is irrelevant to the conventional current method.
Confusing only because of imprecise terms and too many analogies taken too far. I submit that the conventional method is the correct way to go. Otherwise you ignore the way manufacturers mark their semiconductors, and your physical measurement of current with a ammeter will be in an opposite direction from your calculations. You will also find it confusing in circuits where both positive and negative charge carriers exist (like electrochemistry).
Yes, real current exists from positive to negative if the carrier is positive, but in simple circuits, it is not.
The manufacturers' labels do not usually apply to current direction, rather to voltage potential. You would need to know how the devices work in order to make the proper calculations.
Now you see why i suggested abandoning the analogies and going with theory without physical reality and so save the advanced physics for later study. This provides an operational approach that allows one to understand the forest without understanding each individual tree. We can analyze tons of circuits with extraordinary accuracy without ever knowing what current 'flow' is or what really makes up a voltage.
DerStrom8, A battery is a simple electrochemical device that utilizes positive charge carriers.
The Wikipedia entry for electron drift velocity shows an example calculation of a 3amp current flowing through a 1mm wire results in the electrons taking 1hour to traverse a distance of 1 meter. A surprisingly large bulk of electronic hobbyists don't realize this.
It should at the very least be mentioned in passing while attempting to describe functional electronics the basic physics involved, it's not excessively complex to cover the basic physics in passing and it will give curious learners avenues of further self study. Many commonly accepted teaching methods for electronics attempt too strongly in my opinion to shield the user from the true complexities by using analogies that simply don't hold water (like the water ones) which is probably one of the worst analogies I've run across. Electricity is not like water in a pipe on any level. The water in a pipe in this case is metal, what's moving is energy like a wave through the conductor transferring energy the electrons just carry it.
Take the example of an AC circuit, although electrons are transferring energy from one point to another the electrons themselves don't actually go anywhere. In DC circuits you can calculate how long it would truly take an electron to traverse one end of a copper wire to the other but in most cases this is actually an incredibly long period of time.
The Wikipedia entry for electron drift velocity shows an example calculation of a 3amp current flowing through a 1mm wire results in the electrons taking 1hour to traverse a distance of 1 meter. A surprisingly large bulk of electronic hobbyists don't realize this.
No. A battery is a perfect example of an electrochemical device that utilizes negative charge carriers. A battery is made up of two main parts--an oxidizer and an electrolyte. The electrolyte causes the oxidizer element to oxidize (give off electrons), which are negative charge carriers. They are then "pushed out" of the negative side of the battery and attracted to the positive side through the circuit.
Voltage is the potential to do work.
If you hold a brick above your head, it has the potential to do work (gravitional potential).
Current is considered to be a flow of charge carriers such as electrons, positrons, protons, + ions, - ions, holes in semiconductors, etc.
Conventional current flow is considered to be from positive to negative.
However, the direction of flow of the carriers is usually not important.
This is true for positive charge carriers but negative ones flow in the other direction.
When analysing electric circuits, it is easier in the maths to assume conventional flow than electron flow.
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