By NaiChit Fung 2019/08/03
To Design and make prototype of electronics circuit
- To choose electronics component
- To debug a failing circuit
There's few type of electronics component.
| Resistors |   |
| Capacitor |   |
| Inductor |   |
Disclaimer: The following explanation of voltage had made some estimation. This won't be the exactly the same as the explanation you would get if you studying physics.
The first things we are going to talk about will be voltage.
When talk about voltage, assuming you have no electronic or electrical background, the first thing you may think, might be a high voltage warning. However, such warning might make people misinterpret how voltage works.
In Physics, voltage is also called electric potential "difference". Which also suggested that it's some kind of subtraction. Take an example, look at the following picture.
Don't worry, no birds were harmed. Anyway, this is a very good demonstration of the importance of a reference. The power line those birds stood on probably operating over thousands of volt. However, birds won't be killed as there's no voltage difference on where they are standing.
The result persist when electromagnetic force is replaced by gravity. Imagine a ball on a table will fall to the ground if you push out of the edge. However, if you don't push it to the edge (assuming the table is flat), it will remain at the same place, since at the point of view of the ball,the table is its "GROUND". Just like the picture of the birds standing on powerlines. Indeed, the powerline contains high electric potential, but there doesn't exist a low electric potential point to create a potential difference. Hence, the voltage(electric potential difference) is 0V.
Or say it in another aspect, the best way to prevent something from falling, is putting it on the ground. Nothing will fall if it's on the ground at the first place. Even if it's happening on 28th floor. Or, in electrical aspect, no current will flow at all if whole system stays at 50kV (with reference to ground) since there isn't any difference, the voltage of the system will be 0V.
However, if you are being electrical shocked unluckily. During the process, you are actually creating a difference by putting your feet onto the ground; as the ground you stand on are generally connected to the ground of the power plug. As a result, the point where you touch and the ground will have a electric potential difference (voltage) of 220V (or 110V, 230V in some country). Hence, current is going to flow through your body.
Therefore, for measuring the voltage, or perhaps, finding the electric potential difference, you need to find a reference correctly.
Current is a measurement of how much charge is moving per second.
Ohm's Law is a simple yet very important law in electrical and electronic engineering.
While V stands for Voltage, I stands for current and R stands for resistance.
And this picture explain it perfectly.
There's an idiom says, "High voltage will kill". This idiom is not accurate. From the picture, volt only pushes current through resistance; the current (amp) is what going to flow through your body and burn it down. So, good kids don't try it at home.
The simplest way of calculating power, or average power: