What are Volts, Amps and Resistance?? | Electronics - The Basics - Episode 1
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- Опубліковано 10 сер 2022
- Don't know the difference between volts and amps? A bit confused why cable thickness matters sometimes, but not other times? Fear not!
In this first episode of "Electronics - The Basics", you'll learn how to easily understand the difference between voltage, current and resistance simply by seeing how water behaves! You'll also learn a simple formula to help calculate one if you know the other two, and see how much it helps you understand the world about you. - Навчання та стиль
Great video, thanks for explaining the basics. Looking forward to seeing your new videos 👍🏼
Thanks Peter, glad to hear it was helpful! Stay tuned!
Great video, Greg.
Glad you enjoyed it!
Just found this and your channel
Hope you do some follow up videos on this topic, like the multi meter and possibly testing equipment to take camping like the power meter you used for the solar blanket series
Great for us beginners
Great to hear! Yes I do still intend to publish the next two, just been caught up on other things so thanks for the reminder! Love the testing equipment idea too! 👍
I was going to give up trying to understand amps and volts , till I came across your video .
Hope it was helpful! I'll get to the next episode when I get a chance!
Great video but I'm puzzled.
Suppose we connect an AC power outlet of 220v with a contactor supporting a current of up to 16Amps (meaning the house wires in the walls are capable of providing a current of up to 16Amps, and not supporting circuits that have less than a total resistance of 13.75 ohms), to a narrow wire like for an electric heater (I tested one it reads around 70 ohms), we get 3Amps which makes it red hot.
But if we connect the same wires to a human body with 220k ohms, we get 0.001Amps, which is around 1mA and less than the fatal 9mA that you said, and based on my research 1mA causes a faint tingle and less than that is not even noticeable and felt.
I personally have around 400k ohms of resistance, and since more resistance means less current, if I touch the AC outlet, my body will draw less than 1mA and I should not be able to feel anything. but I experienced household 220v AC several times in my life at different ages and it was shocking and painful to my heart.
I was going to conclude the 220v AC is in the shocking/fatal range (but I failed to figure it out that way), also I was trying to say to reduce the current and bring it down to a safer range like 1mA to demonstrate that 220v could be safe, we could reduce the current by adding another higher resistor to the human body circuit. For example a 220k+ ohms resistor. or even with two humans connected in a series... but I am not able to complete this thought process and yet unable to figure out where is my error.
Mate that is a great question and it stumped me too. Your maths is fine. One little difference is that as you'd know, 240V is AC not DC, and the 240V rating is the RMS voltage (the amount of AC power that produces the same heating effect as DC Power), and this is only about 70% of the peak voltage. So an AC waveform which generates 240V AC actually has a peak voltage of 339V. But even at 339V we're still some way from 9mA.
Another factor would be moisture - it doesn't take much sweat on one's fingers to drop the resistance dramatically from several hundred thousand ohms down to 20-30,000. But I think there's still more to this.
So for a bit of a joke I asked ChatGPT the following question:
"An electric shock of about 0.009 amps is fatal. However if the resistance of the human body is 240,000 ohms, a 240 volt electric shock should only deliver about 0.001 amps of current. Why does it give such a severe shock?"
Here, verbatim, is what ChatGPT came back with!!
"When an electric current passes through the human body, it encounters resistance, and this resistance causes a voltage drop across the body. The voltage drop is proportional to the current and the resistance, according to Ohm's law (V = IR).
In the case of a 240 volt electric shock, the current that flows through the body is determined by the resistance of the body. The resistance of the body varies depending on factors such as the contact area of the body with the current source, the condition of the skin, and the presence of moisture.
Assuming a resistance of 240,000 ohms, a 240 volt shock would cause a current of about 0.001 amps to flow through the body (I = V/R). This amount of current is below the threshold for a fatal electric shock.
However, the severity of an electric shock depends not only on the amount of current but also on the duration of the shock. Even a low current can be dangerous if it passes through the body for a long time.
Moreover, the human body is not a simple resistor, but a complex system that contains conductive tissues such as nerves, muscles, and organs. When an electric current passes through the body, it can stimulate these tissues and cause involuntary contractions, called tetanus. Tetanus can cause a person to lose control of their muscles, leading to falls, injuries, and potentially fatal accidents.
In summary, a 240 volt electric shock can be dangerous because even a low current can cause tetanus, and the severity of the shock depends on the duration of the current flow. It is essential to take precautions to prevent electric shock, such as using properly insulated electrical equipment, avoiding contact with live wires, and following electrical safety guidelines."
It's simultaneously informative and scary that artificial intelligence can generate something as substantial and well-worded as that! There may be more to it than just this, but this is probably a good response and one that I hadn't though of myself! Let me know if you have any thoughts.
Cheers mate!
Greg
i have a question what does current mean in german
coud i maby use some screen shots for a presentation
massive thx for the video its helping alot
Glad to hear it's been helpful! I believe 'strom' is the term in German for electrical current. Yes you are welcome to use that in your presentation, please just credit my channel as the source. I am working on the second in the series so make sure you're subscribed!
Hi Greg, I can't see the second video you speak about on power. Did you end up making it?
Hi mate, no not yet, I got caught up on the diesel intake cleaning videos and then was onto the solar blankets (plus life in general!) But parts 2 and 3 will definitely be along at some point (especially for kind supporters like yourself!)
@@TheMusingGreg thanks, I'll keep an eye out!
@@TheMusingGreg we've all been there. still plenty to watch of yours so I'll push on. have you watched any good 12v educationals on UA-cam I can at in the meantime?
Not really sorry mate, I have tertiary training in electrical and electronic engineering and did a heap of 12V stuff on my own cars, and worked installing car audio and security for a while. So I've not needed to go looking for anything else. I'm doing this series because I've rattled on in my reviews about various terms which I can see not everyone's going to understand, or know how they matter. I'll get there when I can! :)
With regards to humans and resistance. I was surfing in a storm once and lightning stuck the ocean nearby, but I didn't get fried???
Yep that makes perfect sense. The electricity is trying its hardest to get to earth, and it did this by striking the water which in turn is touching the earth. So the current went from the surface of the water down to earth at the bottom of the ocean. Unless you were right at the shore and had one hand touching the beach at that very moment, there was no path to earth through you, so no current would have flowed through you. You would only get zapped if the bolt hit you rather than the water - then the current would flow through you, then through the water and down to earth.
It's the same reason birds can sit on a power line and not get electrocuted - they're only touching one half of the circuit. They'd only get shocked if they complete the circuit by touching a neighbouring wire.
So, when the current goes through the circuit... and goes back to the negative side of the battery does it just dissipate? I'm a super noob... lol
Good question mate. Note that current refers to the FLOW of electrons through the circuit, not the electrons doing the 'flowing' if that makes sense. So the 'current' wouldn't dissipate, it would just stop flowing once the battery's flat; but the electrons which flowed from positive to negative during that current flow, yes they would just sit there once there's no difference in voltage between positive and negative. Beforehand there was an excess of electrons on one side so once they've equalised out they're quite happy to stay put, if there's no force to try to move them. 😀
To picture this, imagine two tanks this time, with different levels of water and connected by a pipe at the bottom. That's just like a battery with positive on the 'high' side and negative on the 'low' side, or more elections on one side than the other. As soon as you join the two terminals (or water tanks) the current (water) starts flowing until there's no difference in voltage (water pressure) between the two points. At that point (in simple terms) you have the same number of electrons on both sides and the electrons (just like the water) will just sit there happily until they're connected to something which has a different charge.
Let me know if you need any clarification.
Cheers,
Greg
To be fair - you shouldn’t be dabbling about with any electrical system unless you understand how it all works including 12V vehicle systems.
Definitely right mate. You won't kill yourself on 12V but you can certainly do damage to systems if you don't know what you're doing. This series is trying to help explain the basics so people can at least have some idea what all the terms mean and what they do.