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In electronics and in other branches of the electrical world, we use basic concepts that help us understand the role of electricity and how it works.
When we go shopping we can see a label, some times, on the back of the equipment. This label can give us some information regarding the consuming or necessity of energy that this equipment has. We all have heard the words voltage (V), amperage (A), power (w) and resistance. We also have seen them on those labels, mostly the first three. We could possibly ask ourselves, what are those concepts? how they can explain what we know as electricity?
Lets imagine a battery for a moment a battery transforms chemical energy to electrical energy. We know energy can’t be created nor destroyed, it can only be transformed from one kind of energy to another kind of energy (First law of Thermodynamics). The chemicals in a battery will react and create a difference of charge from one side of the battery to the other, forming the positive terminal (deficient of electrons) and the negative terminal (abundant of electrons). Electrons are little particles charged in a negative way, are present in all matter and responsible for electricity.
This difference in charge causes the battery to have, what we call, voltage across its terminals. Voltage can then be defined as an electromotive force (emf) or driving force that is only present when a difference in charge exists between two points (positive and negative terminals of the battery in this case). The volt (V) is the representative unit of voltage. As said, voltage is a driving force, but a driving force for what? It is a driving force for moving electrons across an electrical circuit when a conduction path is present. So we can then say that voltage pushes the electrons from on side of the battery to the other side of the battery trough a conductor.
Current is an organized flow of electrons (quantity of electrons) that move from one point to another in a determinate time. Amperage (A) is the representative unit of current. We need to have 6.25^18 electrons per second to pass from one point to another in order to accomplish one ampere.
The negative charged of electrons is measured in Coulombs ( C). If we reunite the quantity of (6.25^18) electrons, we in fact have 1C of charge. Mathematically we can then say that 1A is equal to 1C per second (1A=1C/1s). Current will only flow if there is voltage and a conduction path present. If we connect a cable from one side of the battery to the other, electrons will flow rapidly attempting to equalize the difference in charge causing what we know as a short circuit. The flow of electrons will be so intense that the cable could burn and the battery will equalize in short period. This is where resistance comes in handy.
Resistance is an opposition to the flow of electrons, in other words can be seen as a “control" of the current. If we have a constant voltage(constant push) in a circuit and we increase the resistance(increase in oppositon), we will see that the current starts to decrease (decrease in flow). If, on the other hand, we have a constant resistance (constant opposition) and increase voltage ( increase push), the current will also increase( increase in flow) .
Electrons when flow through the resistance they collide with the resistance materials, so if we are using a carbon resistance the electrons are going to collide with the atoms of carbon that form the resistance. This collisions transforms energy to another kind of energy, from electric energy to heat energy, this is called power. So power is the amount of energy consumed or transformed per second. The amount of energy consumption will depend on the circuit used and the application that was designed for. Any other question please feel free to contact me at pagaudio@hotmail.com . I will try to answer as soon as I can.
Disclaimer: All information on this site is provided for informational purposes only! By no means is any
information presented herein intended to substitute for the advice provided to you by any health care or other professional
or organization.
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