For all of our video tutorials, we typically have a written tutorial that provides extra details and additional info - to get even more info about resistors, check out the written tutorial here: www.circuitbread.com/tutorials/whats-a-resistor
I think every reputable school will teach that the resistor is the most common and important electrical device on earth. I made it through intermediate electronics and had just started advanced electronics with op-amps when I ran out of steam. *Some years later, I was reading through the incredibly thick Electronics Engineer's Handbook, cross referenced a college text from the 70's my father bought me and encountered HF radio and it's relevance in conductors in general, not just resistors.* At about 300 mhz., in as little as a 1 inch conductor including circuit traces, inductive and capacitive reactance becomes relevant. Jump into radio engineering, and you find the "loading coil" built into antenna's physical architecture to tune the circuit so it's a stand alone tank circuit, and it's internal capacitance and reactance fulfills the criteria to establish it as a tank circuit. *This can be witnessed if you have ever seen a wi-fi antenna outside the plastic package, and the short portion rolled into a coil.*
Interesting, very much appreciate the clear explanation. I have 0 background in circuitry but have always been fascinated by it. At 36 years of age (last year!) I bought a classic tron.ix lab circuitry kit and starting messing around with the small/elementary experiments. Had to put it down for a bit but have picked it back up so I'm refreshing the basics. People like me love these tutorials because it makes it feel less daunting.
Hi Michael! I turned 36 last year as well and learning electronics is a much better new skill than I tried to pick up last year (you can see in a couple videos a weird spot on my forehead from a failed attempt at a backflip). I'm glad that these are helping out! Sergey is still writing microcontroller and embedded system tutorials, while JB and Herald are trying to finish up the microelectronics series, and I'm hoping to finish writing the 3rd and 4th basic circuits tutorials this week so that we can shoot those next week. These basic circuit tutorials are probably going to be right up your alley but also probably won't be published for another month. In the meantime, hopefully there's a good assortment of tutorials already up to help you. Take care and good luck!
That's awesome to hear! I have an 8-year old son and he likes playing with Snap Circuits but he doesn't watch any of our videos. Maybe I should try - I just worry that he's going to be like, "Ugh, Dad is talking *again*..." 😂
Hay thanks for being here! I love your videos! There are tiny details that I have happened to miss that you explained well, it's extremely helpful to my research!
I'm looking for molecular level explanation? Is it just friction of electrons as the flow through a resistor? Resistors generate heat to "resist", right? What substance provides that precise level of friction and how is it precisely manipulated to give precise resistance?
With the rotational analogy, the resistor is just a gear that has a sticky bearing. It doesn't want to turn, and so it limits the current through the circuit. This analogy was started by Spintronics.
Watched more of the video and have another question, Because the resistor forces the water through a smaller gap, does the voltage required to get electrons through the gap increase? And therefore, that's how resistors use up some of the voltage supplied to the circuit.
This is where having an intuitive understanding of Ohm's Law is really helpful! With V=IR, you can see that if resistance increases (the pipe gets smaller), and you want to keep current the same (same amount of water flowing through), then yes, voltage would need to increase (increase the height or potential of the water). But, in a real circuit, you're *typically* working with a given voltage source so that voltage won't change (For example, 1.5V for a single alkaline battery, 5V for a USB power source, 3.7V for a lithium-ion battery, etc.) So, if resistance goes up or down, current also goes up or down.
Question: On the diagram you showed of water going through a pipe, all the water that hit the narrower part of the pipe went through, and that confuses me. Because, to my understanding, resistors are supposed to reduce the current (water) going through the wire (pipe) but with what you showed, it did not reduce the amount of water going through the pipe. So do resistors actually reduce the amount of current supplied to the rest of the circuit or do they simply slow down the current at that point? Would really appreciate any answers!
Hi Stellular! Your understanding is correct - the resistors reduce the current by restricting the flow of electrons. At around the 3:40 mark, you notice the flow through the "resistor" which is the narrow part of the tube. How that restricts the flow is, imagine if that narrow part of the tube were 4 times as wide, how much more water would be flowing from the top to the bottom? So, it does reduce the amount of water (or "current") to a controlled flow. The second question is really good - the resistors reduce the amount of current through that point. Whether or not there is more current elsewhere in the circuit depends on how the circuit is set up. If there is something else "downstream" or "upstream" in series, then the current through those other items will be the same as through the resistor. If there are other elements in parallel, or different voltage/current sources, then there will be different paths for the current to follow. That's when you start needing KCL/KVL (Kirchhoff's circuit laws) to start calculating values.
@@CircuitBread Firstly, thank you very much for taking the time to answer my questions! And now I have another... Because a resistor reduces the amount of electrons able to pass through it, what happens, physically, to the electrons that can't get through? Is there some sort of buildup? Do the electrons disperse somehow? I feel as though I may have some preconceived misconception hindering my ability to understand some really important detail. Anyway, again, I really appreciate any answers you can give me. Cheers
Hi Stellular! No problem! The electrons that can't get through simply stay where they are. They don't build up, however, as that would mean that they're increasing the voltage potential. This may be a weird way to say it but all the electrons that *want* to go through the resistor, go through the resistor. If the voltage is higher, if more electrons wanted to go through, more electrons *would* pass through. We almost always create a written tutorial to go along with these videos to provide a slightly different perspective on the same thing and also to let you go through it at your own pace. Have you looked at this one? www.circuitbread.com/tutorials/whats-a-resistor I'd be interested to know if that helps make this more intuitive.
@@DanielDavies-StellularNebulla read about drift velocity there u realize how much collisions there that work as resistor nd these collisions increase by increasing length nd increasing temperature decreasing area
Umm, sooo resistors slow down the flow of power, which I assume means that the current (amps?) that came into the resistor is higher than the current that came out? And the voltage stays the same, you just lower the amp? But why? Also, wtf did literally everything else you said in the video mean? I have no idea what induct-what is, or capacitance, or any of the stuff. I understood thermal coefficient (coefficiency?) because you explained that here, but none of the other stuff, that all confused the hell out of me and were just fancy words
We usually use imagery showing that resistors cause bottlenecks but in reality, the mechanism by which they resist electron flow is only in part due to physical restrictions (skinnier material) and a lot to do with the resistivity of the material. As such, it's often not that the electrons are trying to squeeze through a narrower area and are slowing down everything (though that is what we show in our latest video about potentiometers: ua-cam.com/video/LBRM9lARNN8/v-deo.html ) but they are just one part of the whole path impeding the overall flow of electrons from one place to another. I actually do recommend watching that potentiometer video, though, as I think it will help clarify some things.
I watched the video and the start of the video really did help me understand what you mean by " a lot to do with the resistivity" now it's more clearer thanks! And also I'm kinda amazed that you answered to the comment on this video even tho it's been 5 years since it was uploaded 😅, really appreciate the dedication keep up the good work!!
If I have a a motor “turbine” that produces an output of 5v to 12v (fluctuating) how might you recommend I distribute a constant min of 3v or max of 5v to my output? :)
If I have 2 or more resistors in series,I have a voltage divider (resistors limits the voltage) and if I have in paralel it limits the current,my question is if I have only 1 resistor in series,it limits the current or the voltage?
Sorry, I'm not sure if I understand the question. Also, if you have two resistors in parallel, it does not limit the current, both resistors will have the same voltage across them and you will get a current through them proportionate to the resistance values of those resistors.
@@CircuitBread I am trying to understand maybe I am in error.So when we have 2 resistors in series if I use an ampermetre the current it's the same in every point of the circuit,but in paralel the wire is splitting in 2 wires and because of the resistors we have different current,if we have the same resistors,we gonna have equally divided current on each wire. So resistors in series makes a voltage dividers and resistors in parallel makes a current divider.It's my logic good?
No, the resistance does not change in a resistor when you change the voltage (unless you're somehow damaging it). The reason is because resistance and resistivity are an inherent part of that material's property and don't change randomly. However, if you put too much power through it and melt it, then you're changing the property of the material and the resistance. Perhaps not a great metaphor - it's like saying that the road you're driving on becomes more or less bumpy as you speed up or slow down. You're not really affecting the road, but it's affecting how easy it is for you to go fast.
@@CircuitBread but electric field force will increase when we increase the voltage source emf and if due to this force some more electrons move to the conduction band by overcoming or breaking the attraction force of nucleus
Sorry, I thought I had replied to this a week ago. I can see what you're thinking but you're still not changing the property of the material when you change the voltage. You're changing what is happening internally by having more electrons move but as soon as the voltage disappears, the material still has the same properties - they've never changed. To move away from the road example and use a water example - if you have a lot of pressure in a pipe, more water flows through the pipe, if you have less pressure in a pipe, less water flows. But the pipe never changes in diameter based on the pressure or the flow (unless there's too much and the pipe breaks). The only difference is that the electrons are part of the material (whereas water isn't an integral part of a pipe) - however, since it is a circuit, the electrons are moving in a circle and any electrons that leave are immediately replaced, so, again, the material doesn't change.
Yes, exactly. Resistors don't directly affect the voltage. This is where it gets a little more complicated - if the thing generating the voltage can't produce enough current, then the voltage will drop. But that's an indirect affect. For example, a AA battery with a 10K ohm resistor will be able to generate 150microamps without a problem, so the voltage will stay 1.5V. But with a .1 ohm resistor, the AA battery probably won't be able to generate 15 amps, so its voltage will drop. And I really hope that I didn't just further confuse you...
Lithium batteries are more touchy than lead acid batteries, which is why there are typically dedicated IC's that control the charge profile of the battery. I'm less worried about hurting your alternator and more worried about damaging your battery pack. That being said, a resistor is a very simple yet inefficient way to throttle current flow, though you will probably need a resistor capable of withstanding a large amount of power, even if you choose a small ( < 1ohm) resistor.
Funny cause like, resistors dont just make a smaller path for electrons, they use a material with high resistance and when electrins bump into electrons from that material, electricty is converted to thermal energy
So If I connect Arduino pin to an LED and use a resistor ,I limit the current that goes into LED,right? But if I use a voltmeter in parallel with the resistor ,I can see some voltage there which means I,ve lost some voltage too.So that doesn't mean that resistor limits the current and the initial voltage too? please explain me I am really dummy!! :(
The way you can think of it is that you're limiting the current through the resistor because you're dropping all the "excess" voltage over the resistor, not the LED. For an LED to work, it needs a certain voltage to start conducting. Once it has that amount of voltage, any voltage OVER that minimum creates a quickly-increasing current. (Check out the image "LED current versus voltage relationship" here: www.circuitbread.com/tutorials/leds-and-forward-voltage) I actually highly recommend reading that entire article - it's a little bit more technical but should be able to answer all your questions.
@@CircuitBread Now I have another question: In some circuits I've seen from left to right Arduino 5V connected to LED,then resistor,then ground and it worked fine? Why is fine shouldn't the LED be burned?! And btw the link you gave me isn't working :(
Hi Again...Do you think it is possible....at a fee of course, for me to sent you the circuit board for analysis...I could then do the repairs if it is not the micro controllers???
Hi Bob! We're not really setup for that, unfortunately. I'd recommend our discord channel as a free option but it's still pretty small at this point and I (and the other CircuitBread engineers) can only jump in sometimes, so responses are hit and miss. While it's been several years since I've worked with anyone on Upwork, a service like that might be an inexpensive yet effective way to get a review.
I have a doubt using the fluid analogy...when the pipe gets narrow the velocity of the fluid is high so aftrall the same amount of fluid is passing thats not a resistance ...
First, no analogy is perfect, unfortunately. Second, in this case, the challenge is probably that you're thinking of water coming from a hose, not water coming out of the bottom of a barrel of water (or something similar). The water will react differently and, while still not perfect, be a more accurate analogy of how the water flow decreases.
That's actually where the intuitive understanding with this metaphor struggles. Most of us, when we're imagining this, we're imagining covering the end of a house to restrict the flow. In that case, you're actually increasing the water pressure, which is not what happens with electricity. I think it's better to think of it as a tub of water being held up high. If you drill a small hole or a big hole, the pressure doesn't change and water doesn't necessarily flow faster, just more of it flows. I hope that helps!
@@CircuitBread yeah I guess the tube with a hole at e certain height would be a much better way of saying it.But how exactly does it work with electricity.Cause again this way of explaining fails cause all water falls after a certain time.
3:20 this is why I struggle to understand electronics. With water, as with most fluids, narrowing part of the channel it’s flowing through doesn’t “slow” the water’s velocity, it INCREASES it. (Think putting your thumb mostly over the end of a hose). If the resistor is the size of the pipe/hose, wouldn’t it be like _increasing_ the pipe diameter? So saying a resistor allows less electrons through thus giving a lower voltage makes sense to me, but the analogy doesn’t at all.
This seems to be a common question, common enough I may end up doing another video physically addressing just this analogy. In the meantime, I'm going to modify a comment I put somewhere else: Couple of things, I always start with the fact that a metaphor is never perfect. With that, I think the challenge here is that most people are used to using a hose coming from a hydrant, where if you cover the end of the hose, you're increasing the back pressure. It's important to note that, in normal situations, when you open a faucet, you're decreasing the pressure in the system. When you cover your thumb, you're increasing the pressure back up to what it is when the hydrant is off. This is more like having a hose coming out of a hole in a bucket of water suspended over your head, which will have a consistent pressure (as long as the amount of water in the bucket magically stays at the same level).
I think the analogy is ok but I also had troubles with it at first. I know your struggle. V=IR (Voltage = Current x Resistance) First to address your last sentence: A resistor decreases the CURRENT but NOT the voltage! The voltage stays the same, but when the resistance changes for whatever reason, the current must also change. when you stick your thumb over a hose end, yes the water particles accelerate but there are LESS of them going out the end, and the more you pinch it shut the less get out until none are getting past at all, even though up to that point the ones that do are going at a high speed. So think of current not as the speed of individuals but how many in total are on the move, a resistor or a thinner wire gauge RESTRICTS the flow of current. On the flip side, Increasing the diameter of the hose or using a thicker wire LESSENS resistance and allows more water/electrons to be pushed through (by voltage). Voltage is like a massive water tank on a tower, if you have a 1cm diameter hose out it cannot let out as much water as a 1 meter diameter hose. So you can think of Voltage as a water tank, Resistance is the hose, Current is the amount of water getting through it per second, NOT the speed of the water. Hope this made sense
Sorry Shubhangi, I'm not sure if I understand the request. Talk about AC current works in an animated video? We touched on this in an older video: ua-cam.com/video/6IO1ro4urIc/v-deo.html
Good question. Imagine you have a vertical pipe, 1 meter in circumference and 10 meters tall. If you take that pipe and at the 5 meter point, pinch it to a .1 meter circumference, then the flow through the entire pipe, not just at that .1 meter pinchpoint, will be the same. Does that make sense?
@@CircuitBread thank u for ur explanation sir but can i get an actual explanation of what happens like in terms of atoms in resistor and how they obstructs the flow ...pls sir can i able to get that and not water pipe anology I understood water pipe analogy But i want actual case😊😊
Unless you are collecting electrons somewhere in your circuit, all the current generated by your battery will ultimately go to ground. There will be no electrons that get left in between the two. Therefore, all the electrons that go into a circuit will go out of that circuit. And in a series circuit, there’s only one path for those electrons to go. The force acting on every electron (voltage) is the same, the path they travel is the same - they’re all going to travel at the same speed, to the same place. So the flow is going to be identical everywhere along that one path. resistor slows down the electron velocity, but doesn’t collect or stop them. Current equals the number of electrons travelling past a point in a given time - if the electrons travel slower, then that means less current is flowing, but they flow through both sides of the resistor with equal speed on their way to ground. The resistor just dictates how fast the electrons get to flow through it - kind of like how a speed bump can force you to only go at a certain speed A resistor can be viewed as a speed breaker instead of a barrier
@@sumzk great man thanks alot i have learned a good knowledge by ur comment And i also thank @circuitbread bcz through this channel i came to know about resistor by this man
Hi Michal! Typically, as EE's, the resistance is given to us, so that's why I glossed over that portion. To calculate resistance, you need to know the resistivity of the material, the cross section area (which decreases resistance), and the length (which increases resistance), and then it's simply: (resistivity * length) / area Make sure that your units match (so you're not measuring area in square meters and length in millimeters, etc.) and you should be good to go. Hope that helps!
Hey Zulfikar, no metaphor is perfect and one of the challenges with this is that, connected to a city source, plugging up a pipe or hose increases the pressure (the voltage). I think it would be a better metaphor if you imagine that the voltage is a bucket of water at a certain height - the pressure won't increase as you make the pipe smaller.
Not sure if I understand the question. If you put a resistor under water next to a water temperature gauge and then run a lot of power through the resistor, you'll heat up the water which should register on the temp gauge. But it depends on the power and the amount of water. Does that answer your question?
just a min he said that his FATHER IN LAW makes elevators and he saw that when he was in SCHOOL and thought his WIFE was messing with him . DID HE JUST SAY INDIRECTLY THAT HE GOT MARRIED WHEN HE WAS IN SCHOOL????? WHAT !!!
😂 You heard correctly, I got married in college and had a kid by the time I graduated. I was a couple years older than the stereotypical college student when I started but was still pretty young in retrospect.
Hey Brian - some electronics are more complicated but resistors are straightforward. There is no positive and negative, it doesn't matter which way you put them in, they'll work the same. I'm not aware of any three prong resistors, though, unless it's some sort of resistor array.
I'd like to do some tests on this as I've heard quite a few similar comments like this and I think there are some misunderstandings about fluid dynamics. I'll report back with my findings and see if I'm right or wrong. Or both!
I got married as a sophomore in college, when I was 22. Didn't really affect my studies too much until my first was born at the end of my junior year. That wreaked havoc on my grades.
Hey Bob, thanks, I think! 😂 Yes, they are real, I am just lucky, I guess. But on the flip side, I did have braces for several years as a teenager so... I don't know, maybe I could consider that as "paying my dues"?
@@CircuitBread Hi....do you think you could answer a question I have regarding a 1144 count white led photo light with a variable dimmer that checks out ok but does not work??? Is is powered by a 19v adapter....and I get 19 volts to the two leads going to the leds?
Hey Bob - troubleshooting like this is difficult but we could give it a try. Do you have any more information about the photo light? Make and model so I can look at it. And I'm assuming by "does not work" is that it doesn't produce light under any circumstances. Is that correct? Also, UA-cam doesn't notify me of follow up comments, so if I don't respond, feel free to jump on our Discord channel, where I at least get notifications.
For all of our video tutorials, we typically have a written tutorial that provides extra details and additional info - to get even more info about resistors, check out the written tutorial here: www.circuitbread.com/tutorials/whats-a-resistor
I think every reputable school will teach that the resistor is the most common and important electrical device on earth. I made it through intermediate electronics and had just started advanced electronics with op-amps when I ran out of steam. *Some years later, I was reading through the incredibly thick Electronics Engineer's Handbook, cross referenced a college text from the 70's my father bought me and encountered HF radio and it's relevance in conductors in general, not just resistors.*
At about 300 mhz., in as little as a 1 inch conductor including circuit traces, inductive and capacitive reactance becomes relevant.
Jump into radio engineering, and you find the "loading coil" built into antenna's physical architecture to tune the circuit so it's a stand alone tank circuit, and it's internal capacitance and reactance fulfills the criteria to establish it as a tank circuit.
*This can be witnessed if you have ever seen a wi-fi antenna outside the plastic package, and the short portion rolled into a coil.*
You were able to laugh and make fun of yourself.... I respect that. 👍
Interesting, very much appreciate the clear explanation. I have 0 background in circuitry but have always been fascinated by it. At 36 years of age (last year!) I bought a classic tron.ix lab circuitry kit and starting messing around with the small/elementary experiments. Had to put it down for a bit but have picked it back up so I'm refreshing the basics. People like me love these tutorials because it makes it feel less daunting.
Hi Michael! I turned 36 last year as well and learning electronics is a much better new skill than I tried to pick up last year (you can see in a couple videos a weird spot on my forehead from a failed attempt at a backflip). I'm glad that these are helping out! Sergey is still writing microcontroller and embedded system tutorials, while JB and Herald are trying to finish up the microelectronics series, and I'm hoping to finish writing the 3rd and 4th basic circuits tutorials this week so that we can shoot those next week. These basic circuit tutorials are probably going to be right up your alley but also probably won't be published for another month. In the meantime, hopefully there's a good assortment of tutorials already up to help you. Take care and good luck!
@@CircuitBread what a great response
Thank you for taking the time to explain resistors, very clearly put. Much appreciated
My 8-year-old daughter just started building circuits and LOVED this
That's awesome to hear! I have an 8-year old son and he likes playing with Snap Circuits but he doesn't watch any of our videos. Maybe I should try - I just worry that he's going to be like, "Ugh, Dad is talking *again*..." 😂
these short videos are pretty cool to flick through to find info I may need thanks for posting :)
Hay thanks for being here! I love your videos! There are tiny details that I have happened to miss that you explained well, it's extremely helpful to my research!
Thanks for the kind feedback, I'm glad they've been helpful!
My Electronic Teacher Brings Me Here By The Way Nice Video
Such an amzing video compared to the last many videos ive watched, you are an undiscovered gem !
Thank you so much those information is really helping more than that i even get new knowledge thankss
i like it, it's quit useful while as simple ... tnx bro
EXCELLENT VIDEO VERY GOOD AT EXPLAINING AND VISUAL EXAMPLES AND LOVE THE SMALL COUNTER HAHA!! :)
Excellent information 👍👍👍👍👍
Wow excellent description than you! Great explanation, great site, subscribed!
Thanks Bob!
I'm looking for molecular level explanation? Is it just friction of electrons as the flow through a resistor? Resistors generate heat to "resist", right? What substance provides that precise level of friction and how is it precisely manipulated to give precise resistance?
Very good work bro..
thanks..
With the rotational analogy, the resistor is just a gear that has a sticky bearing. It doesn't want to turn, and so it limits the current through the circuit. This analogy was started by Spintronics.
WARNING, resistors do not slow down a current as this bloke just said. Resistors limit the amount flowing, not the speed.
Well, they impede the flow of current 🤔🤷
Watched more of the video and have another question,
Because the resistor forces the water through a smaller gap, does the voltage required to get electrons through the gap increase? And therefore, that's how resistors use up some of the voltage supplied to the circuit.
This is where having an intuitive understanding of Ohm's Law is really helpful! With V=IR, you can see that if resistance increases (the pipe gets smaller), and you want to keep current the same (same amount of water flowing through), then yes, voltage would need to increase (increase the height or potential of the water).
But, in a real circuit, you're *typically* working with a given voltage source so that voltage won't change (For example, 1.5V for a single alkaline battery, 5V for a USB power source, 3.7V for a lithium-ion battery, etc.) So, if resistance goes up or down, current also goes up or down.
@@CircuitBread Okay cool, glad I understand that. Thanks heaps!
CircuitBread hsh
Cir
Question:
On the diagram you showed of water going through a pipe, all the water that hit the narrower part of the pipe went through, and that confuses me. Because, to my understanding, resistors are supposed to reduce the current (water) going through the wire (pipe) but with what you showed, it did not reduce the amount of water going through the pipe.
So do resistors actually reduce the amount of current supplied to the rest of the circuit or do they simply slow down the current at that point? Would really appreciate any answers!
Hi Stellular! Your understanding is correct - the resistors reduce the current by restricting the flow of electrons. At around the 3:40 mark, you notice the flow through the "resistor" which is the narrow part of the tube. How that restricts the flow is, imagine if that narrow part of the tube were 4 times as wide, how much more water would be flowing from the top to the bottom? So, it does reduce the amount of water (or "current") to a controlled flow.
The second question is really good - the resistors reduce the amount of current through that point. Whether or not there is more current elsewhere in the circuit depends on how the circuit is set up. If there is something else "downstream" or "upstream" in series, then the current through those other items will be the same as through the resistor. If there are other elements in parallel, or different voltage/current sources, then there will be different paths for the current to follow. That's when you start needing KCL/KVL (Kirchhoff's circuit laws) to start calculating values.
@@CircuitBread Firstly, thank you very much for taking the time to answer my questions! And now I have another...
Because a resistor reduces the amount of electrons able to pass through it, what happens, physically, to the electrons that can't get through? Is there some sort of buildup? Do the electrons disperse somehow?
I feel as though I may have some preconceived misconception hindering my ability to understand some really important detail.
Anyway, again, I really appreciate any answers you can give me. Cheers
Hi Stellular! No problem! The electrons that can't get through simply stay where they are. They don't build up, however, as that would mean that they're increasing the voltage potential. This may be a weird way to say it but all the electrons that *want* to go through the resistor, go through the resistor. If the voltage is higher, if more electrons wanted to go through, more electrons *would* pass through.
We almost always create a written tutorial to go along with these videos to provide a slightly different perspective on the same thing and also to let you go through it at your own pace. Have you looked at this one? www.circuitbread.com/tutorials/whats-a-resistor I'd be interested to know if that helps make this more intuitive.
@@CircuitBread if area would increase due to high pressure in this area velocity decreases. thus low water current
@@DanielDavies-StellularNebulla read about drift velocity there u realize how much collisions there that work as resistor nd these collisions increase by increasing length nd increasing temperature decreasing area
Umm, sooo resistors slow down the flow of power, which I assume means that the current (amps?) that came into the resistor is higher than the current that came out? And the voltage stays the same, you just lower the amp? But why? Also, wtf did literally everything else you said in the video mean? I have no idea what induct-what is, or capacitance, or any of the stuff. I understood thermal coefficient (coefficiency?) because you explained that here, but none of the other stuff, that all confused the hell out of me and were just fancy words
Hey I am new to this stuff, but I am wondering do resistors create bottlenecks?
We usually use imagery showing that resistors cause bottlenecks but in reality, the mechanism by which they resist electron flow is only in part due to physical restrictions (skinnier material) and a lot to do with the resistivity of the material. As such, it's often not that the electrons are trying to squeeze through a narrower area and are slowing down everything (though that is what we show in our latest video about potentiometers: ua-cam.com/video/LBRM9lARNN8/v-deo.html ) but they are just one part of the whole path impeding the overall flow of electrons from one place to another. I actually do recommend watching that potentiometer video, though, as I think it will help clarify some things.
I watched the video and the start of the video really did help me understand what you mean by " a lot to do with the resistivity" now it's more clearer thanks! And also I'm kinda amazed that you answered to the comment on this video even tho it's been 5 years since it was uploaded 😅, really appreciate the dedication keep up the good work!!
you look like paul rudd more than the man himself xD
Paul Rudd, eh? Well, the man is ageless, I wouldn't be opposed to that 😂
His wife show him a tipe of huge resistor, he didn't beleve it, the size shape and form of that thing : ))
If I have a a motor “turbine” that produces an output of 5v to 12v (fluctuating) how might you recommend I distribute a constant min of 3v or max of 5v to my output? :)
Hey Jaim - this tutorial may help! www.circuitbread.com/tutorials/zener-diode-as-voltage-regulator-conceptual-overview
If I have 2 or more resistors in series,I have a voltage divider (resistors limits the voltage) and if I have in paralel it limits the current,my question is if I have only 1 resistor in series,it limits the current or the voltage?
Sorry, I'm not sure if I understand the question. Also, if you have two resistors in parallel, it does not limit the current, both resistors will have the same voltage across them and you will get a current through them proportionate to the resistance values of those resistors.
@@CircuitBread I am trying to understand maybe I am in error.So when we have 2 resistors in series if I use an ampermetre the current it's the same in every point of the circuit,but in paralel the wire is splitting in 2 wires and because of the resistors we have different current,if we have the same resistors,we gonna have equally divided current on each wire. So resistors in series makes a voltage dividers and resistors in parallel makes a current divider.It's my logic good?
If we change the voltage source for the same resistor, does its resistance change or not? Give reason also....
No, the resistance does not change in a resistor when you change the voltage (unless you're somehow damaging it). The reason is because resistance and resistivity are an inherent part of that material's property and don't change randomly. However, if you put too much power through it and melt it, then you're changing the property of the material and the resistance. Perhaps not a great metaphor - it's like saying that the road you're driving on becomes more or less bumpy as you speed up or slow down. You're not really affecting the road, but it's affecting how easy it is for you to go fast.
@@CircuitBread but electric field force will increase when we increase the voltage source emf and if due to this force some more electrons move to the conduction band by overcoming or breaking the attraction force of nucleus
Sorry, I thought I had replied to this a week ago. I can see what you're thinking but you're still not changing the property of the material when you change the voltage. You're changing what is happening internally by having more electrons move but as soon as the voltage disappears, the material still has the same properties - they've never changed. To move away from the road example and use a water example - if you have a lot of pressure in a pipe, more water flows through the pipe, if you have less pressure in a pipe, less water flows. But the pipe never changes in diameter based on the pressure or the flow (unless there's too much and the pipe breaks). The only difference is that the electrons are part of the material (whereas water isn't an integral part of a pipe) - however, since it is a circuit, the electrons are moving in a circle and any electrons that leave are immediately replaced, so, again, the material doesn't change.
When i was in school, i was never told that resistors have capacitance or inductance... 😮
So, a resistor limits (or resists) the current flow in a circuit, but not the voltage ?
Yes, exactly. Resistors don't directly affect the voltage. This is where it gets a little more complicated - if the thing generating the voltage can't produce enough current, then the voltage will drop. But that's an indirect affect. For example, a AA battery with a 10K ohm resistor will be able to generate 150microamps without a problem, so the voltage will stay 1.5V. But with a .1 ohm resistor, the AA battery probably won't be able to generate 15 amps, so its voltage will drop. And I really hope that I didn't just further confuse you...
So if I wanted to charge a lithium battery pack from an alternator would a simple resistor stop the alternator from being damaged by current draw?
Lithium batteries are more touchy than lead acid batteries, which is why there are typically dedicated IC's that control the charge profile of the battery. I'm less worried about hurting your alternator and more worried about damaging your battery pack. That being said, a resistor is a very simple yet inefficient way to throttle current flow, though you will probably need a resistor capable of withstanding a large amount of power, even if you choose a small ( < 1ohm) resistor.
@@CircuitBread thank you for your information
Funny cause like, resistors dont just make a smaller path for electrons, they use a material with high resistance and when electrins bump into electrons from that material, electricty is converted to thermal energy
So If I connect Arduino pin to an LED and use a resistor ,I limit the current that goes into LED,right? But if I use a voltmeter in parallel with the resistor ,I can see some voltage there which means I,ve lost some voltage too.So that doesn't mean that resistor limits the current and the initial voltage too? please explain me I am really dummy!! :(
The way you can think of it is that you're limiting the current through the resistor because you're dropping all the "excess" voltage over the resistor, not the LED. For an LED to work, it needs a certain voltage to start conducting. Once it has that amount of voltage, any voltage OVER that minimum creates a quickly-increasing current. (Check out the image "LED current versus voltage relationship" here: www.circuitbread.com/tutorials/leds-and-forward-voltage) I actually highly recommend reading that entire article - it's a little bit more technical but should be able to answer all your questions.
@@CircuitBread Now I have another question: In some circuits I've seen from left to right Arduino 5V connected to LED,then resistor,then ground and it worked fine? Why is fine shouldn't the LED be burned?! And btw the link you gave me isn't working :(
Hi Again...Do you think it is possible....at a fee of course, for me to sent you the circuit board for analysis...I could then do the repairs if it is not the micro controllers???
Hi Bob! We're not really setup for that, unfortunately. I'd recommend our discord channel as a free option but it's still pretty small at this point and I (and the other CircuitBread engineers) can only jump in sometimes, so responses are hit and miss. While it's been several years since I've worked with anyone on Upwork, a service like that might be an inexpensive yet effective way to get a review.
@@CircuitBread Thank you!
I have a doubt using the fluid analogy...when the pipe gets narrow the velocity of the fluid is high so aftrall the same amount of fluid is passing thats not a resistance ...
First, no analogy is perfect, unfortunately. Second, in this case, the challenge is probably that you're thinking of water coming from a hose, not water coming out of the bottom of a barrel of water (or something similar). The water will react differently and, while still not perfect, be a more accurate analogy of how the water flow decreases.
Great!!!!!!
With water the flow with resistance applies would be faster,what does happend to electricity in these case?
That's actually where the intuitive understanding with this metaphor struggles. Most of us, when we're imagining this, we're imagining covering the end of a house to restrict the flow. In that case, you're actually increasing the water pressure, which is not what happens with electricity. I think it's better to think of it as a tub of water being held up high. If you drill a small hole or a big hole, the pressure doesn't change and water doesn't necessarily flow faster, just more of it flows. I hope that helps!
@@CircuitBread yeah I guess the tube with a hole at e certain height would be a much better way of saying it.But how exactly does it work with electricity.Cause again this way of explaining fails cause all water falls after a certain time.
This absolutely did not describe "how a resister works".
3:20 this is why I struggle to understand electronics. With water, as with most fluids, narrowing part of the channel it’s flowing through doesn’t “slow” the water’s velocity, it INCREASES it. (Think putting your thumb mostly over the end of a hose).
If the resistor is the size of the pipe/hose, wouldn’t it be like _increasing_ the pipe diameter?
So saying a resistor allows less electrons through thus giving a lower voltage makes sense to me, but the analogy doesn’t at all.
This seems to be a common question, common enough I may end up doing another video physically addressing just this analogy. In the meantime, I'm going to modify a comment I put somewhere else:
Couple of things, I always start with the fact that a metaphor is never perfect. With that, I think the challenge here is that most people are used to using a hose coming from a hydrant, where if you cover the end of the hose, you're increasing the back pressure. It's important to note that, in normal situations, when you open a faucet, you're decreasing the pressure in the system. When you cover your thumb, you're increasing the pressure back up to what it is when the hydrant is off. This is more like having a hose coming out of a hole in a bucket of water suspended over your head, which will have a consistent pressure (as long as the amount of water in the bucket magically stays at the same level).
I think the analogy is ok but I also had troubles with it at first. I know your struggle. V=IR (Voltage = Current x Resistance) First to address your last sentence: A resistor decreases the CURRENT but NOT the voltage! The voltage stays the same, but when the resistance changes for whatever reason, the current must also change. when you stick your thumb over a hose end, yes the water particles accelerate but there are LESS of them going out the end, and the more you pinch it shut the less get out until none are getting past at all, even though up to that point the ones that do are going at a high speed. So think of current not as the speed of individuals but how many in total are on the move, a resistor or a thinner wire gauge RESTRICTS the flow of current.
On the flip side, Increasing the diameter of the hose or using a thicker wire LESSENS resistance and allows more water/electrons to be pushed through (by voltage).
Voltage is like a massive water tank on a tower, if you have a 1cm diameter hose out it cannot let out as much water as a 1 meter diameter hose. So you can think of Voltage as a water tank, Resistance is the hose, Current is the amount of water getting through it per second, NOT the speed of the water. Hope this made sense
Explain how current work in hz in animation video
Sorry Shubhangi, I'm not sure if I understand the request. Talk about AC current works in an animated video? We touched on this in an older video: ua-cam.com/video/6IO1ro4urIc/v-deo.html
If resistor resists the current then why does current is same before and after the resistor
Good question. Imagine you have a vertical pipe, 1 meter in circumference and 10 meters tall. If you take that pipe and at the 5 meter point, pinch it to a .1 meter circumference, then the flow through the entire pipe, not just at that .1 meter pinchpoint, will be the same. Does that make sense?
@@CircuitBread thank u for ur explanation sir but can i get an actual explanation of what happens like in terms of atoms in resistor and how they obstructs the flow ...pls sir can i able to get that and not water pipe anology
I understood water pipe analogy
But i want actual case😊😊
Unless you are collecting electrons somewhere in your circuit, all the current generated by your battery will ultimately go to ground. There will be no electrons that get left in between the two. Therefore, all the electrons that go into a circuit will go out of that circuit.
And in a series circuit, there’s only one path for those electrons to go.
The force acting on every electron (voltage) is the same, the path they travel is the same - they’re all going to travel at the same speed, to the same place. So the flow is going to be identical everywhere along that one path.
resistor slows down the electron velocity, but doesn’t collect or stop them. Current equals the number of electrons travelling past a point in a given time - if the electrons travel slower, then that means less current is flowing, but they flow through both sides of the resistor with equal speed on their way to ground. The resistor just dictates how fast the electrons get to flow through it - kind of like how a speed bump can force you to only go at a certain speed
A resistor can be viewed as a speed breaker instead of a barrier
That is an excellent explanation - thank you!
@@sumzk great man thanks alot i have learned a good knowledge by ur comment
And i also thank @circuitbread bcz through this channel i came to know about resistor by this man
You didn't explain how they work other than just state that they resist current. What about how to calculate the resistance etc.?
Hi Michal! Typically, as EE's, the resistance is given to us, so that's why I glossed over that portion. To calculate resistance, you need to know the resistivity of the material, the cross section area (which decreases resistance), and the length (which increases resistance), and then it's simply: (resistivity * length) / area Make sure that your units match (so you're not measuring area in square meters and length in millimeters, etc.) and you should be good to go. Hope that helps!
..but I never seen a plug n play resistors....most of these component lose 1/2 of its lifespans during soldering...
You were _married_ while still at school?
What the fuck dude, I was still trying to figure out how to not get bullied.
Haha! Yeah, I had a couple years between high school and college but I was still pretty young when I got married as a sophomore in college.
@@CircuitBread My condolences.
I don't get the analogy.
think the flow of water on small pipe will be faster if it connecter with bigger pipe behind it
Hey Zulfikar, no metaphor is perfect and one of the challenges with this is that, connected to a city source, plugging up a pipe or hose increases the pressure (the voltage). I think it would be a better metaphor if you imagine that the voltage is a bucket of water at a certain height - the pressure won't increase as you make the pipe smaller.
What happen if i put resistor into water temperature gauge?
Not sure if I understand the question. If you put a resistor under water next to a water temperature gauge and then run a lot of power through the resistor, you'll heat up the water which should register on the temp gauge. But it depends on the power and the amount of water. Does that answer your question?
just a min he said that his FATHER IN LAW makes elevators and he saw that when he was in SCHOOL and thought his WIFE was messing with him . DID HE JUST SAY INDIRECTLY THAT HE GOT MARRIED WHEN HE WAS IN SCHOOL?????
WHAT !!!
😂 You heard correctly, I got married in college and had a kid by the time I graduated. I was a couple years older than the stereotypical college student when I started but was still pretty young in retrospect.
@@CircuitBread oh
2:55
all these electronics which end is pos and which end is neg on restors and them 3prong ones i am tottaly zero brains on this but would like to learn
Hey Brian - some electronics are more complicated but resistors are straightforward. There is no positive and negative, it doesn't matter which way you put them in, they'll work the same. I'm not aware of any three prong resistors, though, unless it's some sort of resistor array.
The mad scientist also has an explanation that I think you'll enjoy: ua-cam.com/video/lPFxeE5XvgY/v-deo.html
I'm from nepal
Welcome to our channel!
well analogy of water flow is wrong as area reduces water current increases
I'd like to do some tests on this as I've heard quite a few similar comments like this and I think there are some misunderstandings about fluid dynamics. I'll report back with my findings and see if I'm right or wrong. Or both!
@@CircuitBread eagerly waiting for results
My rough tests confirmed what I was thinking, I just need to put together a more visually interesting demonstration so we can create a video for it.
@@CircuitBread excited
Married while in school
I got married as a sophomore in college, when I was 22. Didn't really affect my studies too much until my first was born at the end of my junior year. That wreaked havoc on my grades.
CircuitBread Mind me being nosy and asking what the rush with marriage was?
That small counter is annoying and distracting :(
BUT YOU DIDN'T ANSWER THE QUESTION!
Are your teeth naturally that white...and are they real??? Are you just lucky???
Hey Bob, thanks, I think! 😂 Yes, they are real, I am just lucky, I guess. But on the flip side, I did have braces for several years as a teenager so... I don't know, maybe I could consider that as "paying my dues"?
@@CircuitBread Hi....do you think you could answer a question I have regarding a 1144 count white led photo light with a variable dimmer that checks out ok but does not work??? Is is powered by a 19v adapter....and I get 19 volts to the two leads going to the leds?
Hey Bob - troubleshooting like this is difficult but we could give it a try. Do you have any more information about the photo light? Make and model so I can look at it. And I'm assuming by "does not work" is that it doesn't produce light under any circumstances. Is that correct?
Also, UA-cam doesn't notify me of follow up comments, so if I don't respond, feel free to jump on our Discord channel, where I at least get notifications.
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