Narrator for technical explainer video
Middle Aged (35-54)
North American (General)
Note: Transcripts are generated using speech recognition software and may contain errors.
Voltage current and resistance are the building blocks to understanding electricity though, we cannot see them. We can measure them with multi meters, spectrum analyzers and oscilloscopes. So to understand what we are measuring. We need to review how voltage current and resistance relate to each other. Welcome to our lectures and learning video on OEMs Law. If you're new to the channel, be sure to subscribe to see more videos on thermodynamics, nuclear power and other fun learning stuff. If you enjoy this video, be sure to give it a like, Let's dive in the three basic principles in this video can be explained using electrons more specifically, the charge that electrons create Voltage is the difference in charge between two points Current is the rate that charges flowing between two points. Resistance is how the material between the two points tries to slow down the flow of the charge. So when we talk about these values, were really describing the movement of the charge and therefore the behavior of electrons. A circuit is simply a closed loop that allows charge to move from one place to another components in the circuit allow us to control this charge and use it to do work when describing voltage current and resistance. A common analogy is a water tank. In this water tank analogy, charges represented by the water in the tank and system voltage is represented by the water pressure and current is represented by the water flow. So for this analogy, remember that water is our charge pressure is our voltage and flow is our current if you have a water tank some height above ground and there's a pipe or hose coming out of the tank? The pressure measured at the end of the hose is the voltage. The more water we put in the tank, the higher the pressure, which in our analogy means the more charge we put in the tank, the higher the voltage the tank is now our battery storing our charge. If we open a valve at the end of the hose we have flow, this is current. The higher the pressure in the tank, the higher the flow. Now, how much flow we have passed a point per unit time. Depends on both the size of the hose and how much charge we have in the tank. The flow or current is also affected by how open or closed the valve is. A valve more open, tends to provide less resistance to flow and we get more current. A valve more closed represents higher resistance in our circuit and we get less current flow. Now, let's look at that relationship. Mathematically, voltage equals the product of current and resistance for a given voltage. If you have higher resistance, you'll have lower current for a given current requirement, you'll need a higher voltage to overcome a higher resistance. Let's look at some numbers. To better visualize this relationship. If I have a 12 volt battery attached to a circuit with exactly one ohm of total resistance, then I'll have 12 amperes of current flow. If I have that same battery but have three homes of resistance, then my current flow drops to four amperes. What if we don't know how much resistance is in a circuit. We simply rearrange the equation to find the missing term. If we have that same 12 volt battery and we measure a current flow of 2.5 amperes we can divide our charge by the flow and find the resistance. Let's try working on a more realistic problem if we have an L. E. D. With a maximum current rating of 0.2 amps and we plan on powering it with a nine volt battery. How big of a resistor do we need to ensure? We don't ruin our L. E. D. Let's set up what we know. We have a nine volt source and we divide that 9V by the maximum current flow of 0.02 amps. That gives us a required resistance of at least 450 homes. And that's the building block for analyzing a basic electrical circuit. Knowing how voltage current and resistance all work together is important. Before moving on to more complicated concepts like conductance and capacitance. Look for our future video on Kirchoff voltage law to explain why that resistor will work on either side of the L. E. D. Crazy. We know, but it's true. We hope you enjoyed the video. Thanks for watching