Talk:Electronics Fundamentals
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old course content for archival untell its decidily uneeded[edit source]
Syllabus==
- Day 1: Atoms, electrons, electron flow.
- Day 5: Ohm's Law
- Day 10 Conductors and Circuits
Day 1=== What are electronics?
Electronics is the study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles in devices such as thermionic valves and semiconductors. The pure study of such devices is considered as a branch of physics, while the design and construction of electronic circuits to solve practical problems is part of the fields of electrical, electronic and computer engineering. (wiktionary)
In basic terms, electronics deal with electrons, photons, atoms, magnetic field, quantum physics, math, and components used to build machinery.
Don't worry if you've never taken a chemistry class, a physics class, or a class in quantum physics.
To tell you my opinion.
- 1. No one truly understands quantum physics. (even the professors, it's all guesswork)
- 2. Many of the physics included in basic electronics are conceptual meaning you can imagine it.
- 3. The main type of chemistry you will be dealing with is identifying elements and seeing how they react to one another more than using tons of math figuring out chemical formulas.
I would like to say before we begin that having a basic understanding of algebra is useful.
x*y=xy (if you don't understand that you may want to work on your algebraic expressions)
Today we will be covering the atomic part of elements. (Don't worry it isn't too hard)
The atomic model that will be used for today's lesson is the Bohr Model. The Bohr Model is a physical model that depicts the atom as a small positively charged nucleus with electrons in orbit at different levels, similar in structure to the solar system. Although essentially false, the Bohr model is still commonly used and taught today because of its simplicity.
- Atoms, the smallest particles of matter that retain the properties of the matter, are made of protons, electrons, and neutrons. Protons have a positive charge, electrons have a negative charge that cancels the proton's positive charge. Neutrons are particles that are similar to a proton but have a neutral charge. Particles with the same charge repel each other and particles with opposite charge attract each other. If a solitary positive proton and negative electron are placed near each other they will come together to form a hydrogen atom. This repulsion and attraction (force between stationary charged particles) is known as Electrostatic Force and extends theoretically to infinity, but is diluted with distance.
If you've ever taken two magnets and tried to connect North to North, you would notice that they repel each other. The reason for this is because they are like charges. However, when you take North to South they attract each other.
Opposites Attract. *Law of nature, science, and infinitive theoretical views.
For the Bohr Model: Electrons could be seen as antisocialist. Electrons are like negative people. They think that protons are repulsive and a bunch of fascist dictators. The neutron stays out of it, however the protons are cowards and sticks close to the neutron. I'm pretty sure that the electron stays negatively charged and away because it thinks the proton and neutron are both nuts.
Since electrons, also called negatrons are negative, they have been given a special symbol.
- e−
Have you figured out why they are called negatrons? If not, the reason is because they are negative.
Long ago scholars would argue about electrons. People wondered if they were positive or negative. No one at that time really knew. However, as technology had become more sophisticated, people were able to tell the electrons were actually negative (through hall effect) .
Thus, the term negatron came about.
- Convential flow was the first predetermined way that an electron flowed out of a terminal.
What is a terminal?
A terminal is the positive side of a "battery" or else the negative side. (They are both a terminal.)
The word battery is too commonly used today and the correct term is cell. In case you are wondering, a battery is one or more cells connected together. (All this will be explained in later lessons)
People believed that electrons flowed out of the positive terminal of a cell. This idealistic view was known as conventional flow.
However, people eventually had enough technology to track the tunneling of the electron. Tunneling has to do with traces an electron leaves behind. Somewhat like a person leaving behind foot tracks in the mud.
When this was found out people decided to call this new flow, electron flow.
Each atom has a different number of shells. Electrons are located on these shells. There may be one shell. There may be two shells. There may even be 5 shells. One has to wonder, what are these shells? The shells are planes that the electrons are located on and they spin around in a path around the atom on them.
There are a certain number of electrons on each shell though.
The easiest way of figuring out how many electrons are on each shell is to use some simple algebra.
- 2n^2 = Amount of electrons on a certain atomic shell.
2*n^2 = 2(n*n).
If you look on the picture of the Bohr Model, you'll notice that each shell is marked with a
- n = 1 OR
- n = 2 OR
- n = 3 OR/AND
- so and and so on.
n is basically like a question mark. If i were to show you the word Racec?r and I were to ask what the question mark stood for, a majority would probably reply "a". The letter is just a letter represent what shell the electron is on.
- Shell 1 is (n = 1)
- Shell 2 is (n = 2)
- Shell 3 is (n = 3)
in other words.. the n stands for shell number but is a simplified way of saying shell number.
- Note under construction.
All of Earth's elements can be found on the Periodic table of elements.
Day 5: Ohm's Law[edit source]
Ohms law is the most basic law we use in electronics. Most problems we will encounter will involve ohms law, or another law derived from ohm's law.
V = I · R
Voltage = Current times Resistance
There will be many problems for you to work out.
There are different version of this.
- P = Power (watt) Example: To power the flux capacitor I would need 1.21 gigawatt of power.
- I = Current (ampere) Example: I have a current of 5 ampere.
- E = Electromotiveforce (volt) Example: I have an electromotive force of 12 volt.
- R = Resistance (ohm) Example: I have a resistance of 1000 ohm.
NB. Sometimes it is more useful to think of voltage as potential difference. Voltage is a measure of the difference in potentials between two points. This helps to explain the current's tendency to flow around a circuit.
Also, always remember that voltage must be measured in parallel with a line, where current should be measured in series. Power metres must be connected in series AND in parallel, as power is a measure of voltage times current (a power meter measure voltage and current separately, then multiplies the two to find the power)
A good way to remember all of this.
P-I-E-R
I went fishing on the pier.
P = I * E
A good way to remember this: Everyone loves pie. How it's used:
I = E/R I = the square root of P/R I = P/E
Hopefully by now you should be ready to do some basic calculations. Knowledge of common algebra is assumed, and most definately required.
1) Most cars these days have a stereo player in them, as does mine. My stereo runs off 12 volt (from the battery) and draws upto 10 mA.
-What resistance would be encountered at this point? -How much power will the stereo consume at this point?
2) If I use a 15 A fuse to protect a pre-amplifier circuit with an internal resistance of 10 ohm, how much voltage can I source before the fuse will burn out?
3)Using a 200 W amplifier powered by 12 V, how much current can I source?
-If this amplifier is running a 5 ohm speaker, how much power will be delivered?
Day 10 Conductors and Circuits[edit source]
Conductors are materials that conduct electricity (usually metals), allowing it to flow through with minimal resistance. All materials offer some resistance but it wont matter for now as long as your not trying to use wires that are hundreds of feet long.
Type of conductors are conductor materials, semi-conductor materials and non-conductor materials.
The semi-conductor materials are mainly based on an important process called (Doping) i.e: inserting certain type of elements to the atomic structure of other elements, this process leads to obtain positive holes and excess negative charges ,which moved by an applied voltage to run in a certain route which we called it then , the P-N junction. first: the excess negative charges cause we should be aware that all (Group V) elements have usually more than 4 electrons,when they applied to other elements, it leads to let an individual negative electron charge(free electron) which leads to a Negative charge carrier. second: postivie holes cause
Some elements materials from (Group IV) when they applied to other elements they attach by all surrounded atoms leaving a hole on the atom nuclei (unattached) which leads to form the positive other part they called it a positive hole.
Where we have positive hole and negative , we have then a P-N junction which is widely used in electronics field. P-N junction leads to run electricity in certain circuit route determined by the forwared Bias or the reverse Bias in circuits.
An electronic circuit is an instance where electricity flows from the one terminal of a battery to the other. when current is flowing through a circuit it is a "closed" circuit. When you flip a switch on a flashlight. "on" it "closes" the ciruit making the light come on. When you flip it to "off" it turns it into an "open" circuit, meaning that there is now a gap in the connection between the + and – terminals of the battery, not allowing electricity to flow.
resistors are connected in parallel to LED's to reduce the amount of current entering it[edit source]
I think this is bad example, usually resistors are connected with LED in series:
Example, in Light Emitting diodes (LED's) resistors are connected in parallel to LED's to reduce the amount of current entering it likewise it is connect in series to capcitors e.t.c.
-- Alexey Vazhnov (discuss • contribs) 01:32, 2 January 2023 (UTC)