I will spare everyone the history lesson, and dive into the purpose of this post. In order to understand electronics and how electrical circuits work, we have to understand how to view electricity. Electricity can be pictured as flowing water. In fact many parallels in electrical principles can be applied to other applications, everything including the human body. If you can picture electricity in some form of analog, it makes understanding electrical circuits and how they work just that much easier. After all grasping something like electricity that cannot be seen or touched can be difficult. Throughout my exploration I will continue to use water flow as the analog for electricity because this is what helped me understand what electricity is.
There are three parts of electricity that we will talk about in this post.
First is voltage, also known as potential difference. You can think of voltage as a slope in a hill as water flows down. I'll get to how that fits together in a bit. Depending on the amount of voltage versus resistance will determine how much of the next topic will flow.
Now I'll introduce the next part. Current. Current is the rate of flow that electrons are traveling. You can think of this as the speed of water as is goes down a hill.
So how does this all come together? Voltage or potential difference is the hill plus the weight of water, as you slope the hill more and water that is on the hill will flow down the hill. That rate of flow down the hill is the current or the rate that the water is flowing down the hill.
There is a third piece to the puzzle that is known as resistance. You can think of resistance as all the leaves and grass on the hill as the water goes down. Going back to our hill and water example. If the hill had no grass or leaves or anything getting in the way, the water would just slide down at the maximum flow (which is so fast that its hard to even imagine water going so fast). Let say we had some grass on the hill, the water would now flow slower since it is now being slowed down by having to go through grass just to get down.
Now how do these parts relate? Let say we had grass on the hill and the water was flowing too slow! (I.E. low voltage but resistance was high causing the current to be low.) To make the water flow faster we can do certain things. A) we can remove some grass (lowering the resistance) B) we can increase the pitch of the hill to force water to go down faster! or C) we can increase the amount of water!
What is this relationship actually called? This is called Ohm's Law where Voltage = Current * Resistance.
Here's the breakdown of the scenarios above.
A) Removing grass is the same as lowering resistance. When that happens resistance goes down. However, the hill doesn't change slope which means its voltage does not change. If that is the case Voltage / Resistance = Current. This means that as resistance decreases, current will increase, meaning that the water will flow faster!
B) Adding a sharper slope increases the voltage because the potential difference from the top of the hill to the bottom of the hill now has increased. Looking at Ohm's law. If we increase voltage, fix resistance. Current is the only variable that can change. Again, Voltage / Resistance = Current, while Voltage is increasing and resistance is fixed, current will continue to go up.
C) Adding more water will increase the flow of water. We are actually increasing the flow by adding weight to water causing the potential difference to increase. We'll talk about this more when we get to analyzing circuits as pipes. As we increase the amount of water the potential increases meaning we have the same effect as B.
Ohm's law is one of the most important equations to remember while doing any form of electronics.
I hope this helps some people out in understanding the relationship of resistance, voltage, and current. As time goes on, I'll cover individual components and basic theory.
Thanks for reading!
