Impedance Explained.
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- čas přidán 27. 01. 2024
- In this video I compare similarities from the physical world that you can see and touch, to help share how I think about Impedance.
You will learn about “Opposing” forces called “Reactance” and how these, together with “Resistance” combine to form what we call “Impedance”.
Whilst I do go through some formulas, these are not the key intended purpose of the video. For many people, the formulas are not really important.
What is more important, is to be able to visualise in your mind exactly what is going on with AC circuits and to imagine that in a way that makes sense to you.
I hope the analogies I share, which I have picked up from others over the years, really help your thinking as much as it has me.
See my follow up video explaining Impedance Matching here:-
• Impedance Matching
Topics Covered
-------------------------
- Resistance
- Impedance and opposition to current flow
- Capacitors
- Capacitive Reactance
- Inductors
- Inductive Reactance
- Impedance Triangle
Symbols
--------------
R = Resistance, measured in Ohms
Z = Impedance, measured in Ohms
X = Reactance, measured in Ohms
C = Capacitance, measured in Farads
L = Inductance, measured in Henrys
Xc = Capacitive Reactance, measured in Ohms
XL = Inductive Reactance, measured in Ohms - Věda a technologie
I *finally* understand impedance. Thank you. This is probably one of the best videos I've ever seen on CZcams.
Thank you. I'm pleased you found it of use.
Impedance is both Resistance and Reactance.
Seconded
Thirded
Resistance vs. Reactance:
Resistance is a fundamental property of a material or component that opposes the flow of electric current. It depends on physical characteristics like the material's resistivity, length, and cross-sectional area. For example, a resistor with a certain value (say, 10 ohms) will always resist current by that amount, regardless of the type of current (AC or DC).
Reactance, on the other hand, is an *emergent* property in AC circuits. It doesn't come from the physical characteristics alone but from the way capacitors and inductors interact with the changing AC signals. Reactance depends on the frequency of the AC signal and the phase difference between voltage and current.
In other words:
Resistance is like a steady, predictable barrier to current flow.
Reactance is like a dynamic barrier that changes with the frequency of the AC signal
Reactance is a type of resistance that only occurs in components like capacitors and inductors, which are found in AC (alternating current) circuits. Unlike regular resistance (like you find in a resistor), which simply resists the flow of electric current, reactance is a bit more complex because it depends on how the voltage and current interact over time.
In a capacitor, the current leads the voltage. This means the current changes direction before the voltage does. In an inductor, it's the opposite: the voltage leads the current, so the voltage changes direction before the current.
This difference in timing, or "phase," between the voltage and current creates what we call reactance. Because of this phase difference, the voltage and current don't reach their maximum values at the same time. This makes the ratio of voltage to current (V/I), which we call impedance in AC circuits, change.
Here's how it works in simple terms:
Capacitive Reactance (Xc): In capacitors, the current leads the voltage. So, at any given moment, the current is ahead of the voltage in its cycle. This "leads to" a certain kind of resistance called capacitive reactance.
Inductive Reactance (Xl): In inductors, the voltage leads the current. So, the voltage is ahead of the current in its cycle. This results in a different kind of resistance called inductive reactance.
Both types of reactance affect how AC circuits behave, but they do it in ways that depend on the frequency of the AC signal. Higher frequencies increase inductive reactance but decrease capacitive reactance, and vice versa.
So, reactance is like resistance, but it’s special because it comes from the phase difference between voltage and current in capacitors and inductors.
Imagine resistance as a speed bump on a road - it's always there, and it always slows down cars (current) by the same amount.
Now, think of reactance as a wave on the ocean. The resistance to a boat's movement (current) changes depending on the wave's height and speed (the AC signal's frequency). If the waves are high and fast, the boat might struggle more (inductive reactance). If the waves are small and slow, the boat has an easier time (capacitive reactance).
So, reactance emerges from how the waves (AC signals) interact with the boat (capacitors and inductors), while resistance is just the speed bump's fixed, unchanging opposition to the car's movement (current).
Then there's the semiconductor effect where (for a PN junction) the voltage has to exceed a certain point before current flows.
Phil Hartley blew my mind when he pointed out that the energy is in the fields and the fields are in the substrate, not the copper. Thinking in terms of fields, I've been able to design much more effecient pcbs.
Speed bumps affect cars dynamically in that if they are hit at great speed or at an angle the vehicle could lose control or take major damage.
I loved your comment clarifying reactance. However my mine is such that I find myself questioning points.
If only my math teachers told me this when I was in school, I would have understood it. All they had to mention was "You can easily calculate all kinds of things with speakers and amplifiers" and I would have paid attention.
Thanks for the comment. I never learnt well at school, it was only when I started working and self studying did I really feel I was understanding things.
A truly excellent explanation of inductance. You always know when you have a good teacher when you come away from something knowing you've truly understood the subject.
Many thanks for your comment. I'm please that so many people have found this video useful and I am truly humbled by all the great messages that people have kindly sent.
I am very busy with my daytime job right now and have struggled to find time for further videos recently, but I promise more are coming. I have a long list of ideas to get through, so please keep an eye out and make sure you Subscribe.
I teach electonics I really liked how he built the explanation up.
Thanks for your comment. I plan to publish more videos like this soon. Make sure you Subscribe.
Very clear and concise explanation with great analogies and proof on the bench.
Much appreciated!
This is the best impedance explanation video ever made. Thank you so much for sharing your knowledge.
You're very welcome! And thanks for the comment.
When I was competing in in car audio I had to measure everything in Impedance, Even the DC values. My linked amps pulled over 700 Amps, the resistance in my single 18 sub increased 150% from 0,5 ohms to 1,5 ohms under the 6kw power I push through it, and I had yet even one more value to add into the equation, heat. the heat generated into the wires and voice coil also increased resistance and impedance during load. outside temperature, barometric pressure. generator and battery voltage, seat positions and everything had to be taken into account. in 2012 I became Europe Champion with this car using a factory defect Sub. I knew exactly how every aspect of the system would respond in every way of every day when I had that. I miss playing with it. I have the equipment but nothing to use it in anymore. and rules in my country have made it harder to play freely today as well
Thanks for the comment, it seems you had a fantastic and very interesting hobby.
To become European Champion says a lot. Please keep engaging with this channel, I am sure your input to this growing community of electronics hobbyists and enthusiasts will be well received and useful.
Am an electrician, had no clue about impedance, thanks! May not really effect my day to day, after all we just read the nameplate, but interesting to learn how they come up with the numbers!
Greta video! This helped me crystallize my understanding of impedance more than any of my electrical classes did
Thanks. The intention was indeed to help people better visualise this topic in their minds.
I've been trying to understand impedance for a while. I've watched many videos on the subject, but finally I understand it and how it all relates. Thank you.
Glad it helped!
I've never seen those analogies before. Well done!
Thanks. I cannot claim to have been the originator of all the analogies used, I picked most of them up from others and found them to be very useful. I am simply putting it all together and sharing the knowledge.
Trigonometry, wow. Simple trigonometry you say. I had difficulty with basic math in school. What in the world am I doing watching a video about trigonometry? I have memorized XL=2pyeFL and XC=1 0ver 2pyeFC. I have also memorized Z, Impedance and what that is. Phase angles are another story. All of this is exciting to learn and watch in practice. I can't believe I'm saying this. I worked at the Power Company Substation division for many years. Phase Angles came up often but I'll admit I looked past it. Our relay techs took care of it. I did learn in electronics school about the current and voltage leading or lagging in circuit. Your video is fabulous. Thanks. Hope I didn't bore you with my life time adventures.
Thanks for the comment. Most people don't really need to understand phase angle in their mainstream jobs even if you are working with electronics. I have many good engineers that have never really looked into it. In my view, its good to get an understanding of something like this, at least once and even if you then forget the detail you will always recall the basics and the concepts.
Fantastic.ö! Wish I'd had this when I was trying to study electrical engineering. They never managed to explain it in a way where the intuition didn't just disappear in the math.
Thanks. Quite a number of people are commenting similar and I agree, traditional education always seemed to miss out the real explanation of things.
And this is why spiral wound spark plug wires have low resistance with a ohm meter but still resist the spark and generate low noise. A slight of hand from the marketing people.
explaining how ram pump works also helps to understand inductance and boost converters
The thing with the diagram showing a person being pushed through a tube, is that it's really just a visual for DC. For AC, it's more like pushing someone on a swing. That is, the electrons are really just moving back and forth in place; what flows through the tube is the signal to do so, like people in a stadium wave. Resistance is like the friction/air resistance that limits how high you can push the swing. Reactance, then, is a function of how efficiently you push them, given the frequency at which the swing resonates. If there's very little resistance but you push the swing at exactly the wrong times, impedance can still be very high (that is, you won't get the swing/current very high).
I didn't understand these concepts well for months, but after watching this video, I understood them very well
Please make more videos.
You explain very well😍
Thanks for your comment, it's very much appreciated. I'm glad these videos are reaching the right audience.
Brilliant! Ditto all of the complimentary comments. This particular point (reactance) has eluded me since barely passing my electronics class 40-some years ago. I get it now. AWESOME. Thank you!!
Thank you. Glad it's helped.
Same here 25 years ago😂
4:00 in the morning, and you're clear enough to keep me awake and interested. I would have gotten more from my freshman physics class 30+ years ago if you'd been my prof. I especially appreciated the mechanical analogies of the bicycle pump and the flywheel which gave me something I could understand immediately and will remember for the rest of my life. I do wish that, having derived the impedance, current, and phase angle of your circuit, you had set it up and shown the measurement as you did for the single components.
Thanks for the comment. Yes that would have been good to include.
i love your teaching style , thankyou very much
Great explanation, thanks. Wish I'd seen this when I was studying for my amateur radio license.
Thanks, I presume you passed though? That username looks remarkably like a call sign.
@@paulpkae Yep, I passed. Not my call sign, but it does look like one, doesn't it?
Very good. Thank you. I'd previously only known of using ferrets to hunt rats. I didn't know that they were useful for electrical engineers, too.
Thanks. Not sure about "ferrets", but I did mention "Farads" 😆
This is the best video I've seen on this topic. Great examples and demonstrations. Very well done! This is the first video I watched of yours and can't wait for more. If you need ideas I would love a detailed video on CTs. Thanks!
Thanks for your comment. I will put your suggestions onto my list.
This is amazing, very clear explanation
Thank you for your comment.
Excellent video ....the analogies are terrific!
Glad you like them!
Good analogy
Awesome explanation. You’ve got a new subscriber. I like high quality contents and this video is a nice example of that.
Thanks for your comment and thanks even more for Subscribing.
Very clear explanation! I jumped into electronics as a hobby a few years ago. I've probably read all of this at some point. I even have an LCR meter and know that reactance can change with frequency, but i never had an intuitive understanding of this until now. Your description and visualizations really helped me tie it all together. Thanks!
@scottduckworth3299 Thanks, that's exactly what I was hoping for with this video. To reach people who deal with impedance, but struggle to understand it or visualise what's going on.
Absolutely brilliant explanation!
Many thanks!
Why was school not like this! Why are things so easy made so complicated!
They did it deliberate 🤣
Actually, I think many teachers suffered from not fully understanding the subject in sufficient depth themselves and that always makes it harder to explain in a clear way.
If you have a real interest in a subject and driven to learn, and constantly ask "why"; then you begin to get complex things very clear and simple in your head.
And, sharing that knowledge is one of the most rewarding things!
Excellent presentation of resistance, impendance and reactance. Thank you for the time being spent on that thing
Many thanks for your comment.
This is a really great explanation! Thank you for sharing. Brilliant!
Thanks, glad you enjoyed.
Wonderful! Best video so far!!! Bravo!!!
Wow, thanks!
brilliant video !! thank you
Thanks for this, very well explained.
Thanks, glad you enjoyed.
Yes. very nicely explained. I hope people who are new to impedance learned something. I definitely learned how to keep things simpler when explaining :D
Thanks.
Great Explanation!
Great! Fantastic that you can get all that from the right triangle! I learned a lot from this, cheers!
Thanks. Depending on how you approach it, electronics does not need to be complicated. I have found that most thing simply boil down to Ohms law in the end.
Thanks for explaining this in such a clear and simple way!
OK, now I'm ready for a 3 phase motor with a start up capacitor!
Please explain how that works!
Thanks for the comment. I will add your request to the growing list. :)
3 phase motors dont have starting capacitors, as theyre three phase? some _may_ have power factor correction or "run" caps, but its pretty unusual?
the whole point of the capacitor is to give a phase shift on a secondary phase on single phase motors. and fix power factor for run caps...
I love that kind of content. Thanks!!
Thanks for the comment. I really hope it helps people in the same way these analogies have helped me.
very good explanation. I've always had a problem understanding impedance.
Thank you. I'm glad you found it useful.
Great video on this hard to internalize topic
Glad you enjoyed it
Thank you, it's a good explanation really.
Glad it was helpful!
Great video and explanation. I especially loved the phase angle from the triangle.
Thanks for the comment.
@@paulpkaewhat is the meter you use. Is it some kind of signal generator?
@@pulsedmotor that meter is an NTi Audio Minirator MR PRO. Its a combined Impedance Meter & Signal Generator, with a few other functions. It's a professional grade meter that is commonly used in my profession as a PAVA engineer (Public Address & Voice Alarm).
Thanks for the great video, explaining impedance so I could understand it as I never could before.
The subject of phase angle polarity, if that is the correct term, being just touched on, left me searching for enlightenment.
I realize that expounding further upon the subject of phase angle would have stretched this excellent video a bit far.
I was curious as to the phase angle calculation of a circuit that has more capacitive reactance than it does inductive reactance, the opposite of the example in this video.
I imagined that the hypotenuse of the triangle would be on the negative side of the resistance line in a circuit having greater capacitive reactance, where when displayed on a graph, the hypotenuse would be below the horizontal "resistance" line, rather than above it, resulting in a phase angle of the opposite direction from the example shown in the video.
As I never was a math whiz, I needed a bit of clarification on the subject of understanding and determining negative and positive phase angles.
So, I checked elsewhere, and, in my journey, I found a mnemonic reminder regarding phase angle polarity in this video,
czcams.com/video/g8VqHKQOHRk/video.htmlsi=jxaeHAwORVK0dOGr
The mnemonic is "ELI the ICE man", showing that in a circuit having greater L, inductive reactance, use the name ELI, where voltage "E" comes before current "I" in the name ELI, resulting in a positive phase angle; and where in a circuit having greater C, capacitive reactance, use the word ICE, where current "I" comes before voltage "E" in the word ICE, resulting in a negative phase angle.
I thought that I'd share it for others who may have been also wondering about phase angle polarity.
I hope that I described the phenomenon correctly.
Please correct me if I'm wrong.
To those who already knew that information without having to search further, well, I guess that I'm a bit envious of your knowledge.
It seems simple now that I've researched the subject a bit further.
I'm still not a math whiz, though.
Cheers to all! 😊😊👍👍
Brilliant! This video could not be improved upon. I wish you had videos explaining everything related to electronics! I have read and read and read about this but until now, I never understood it. Thank you!
Thanks for your kind words. It means so much to get such feedback and makes all the effort worthwhile.
My pleasure. I'm on the winning end of this deal so please keep creating excellent content and I'll continue to provide positive feedback!@@paulpkae
Thank you!
i don't comment a lot but best explanation of impedance better than my professor explanation.
Many thanks. I'm glad in this instance, you did comment 😁
Great vid Paul, nicely explained ! AC Theory did and still does my head in :( one thing that's useful to know and sticks in my head from college, looooooong time past, was those little formula's like V/IR and relevent here is ICE (Current Leads Voltage In A Capacitive Circuit) and ELI (Voltage Leads Current In An Inductive Circuit) Enjoying your Vids. Les
Cheers Les.
so easy to understand, tks sir
Many thanks for the comment, much appreciated.
Fantastic video and the clearest explanation you could get. Really good that the maths is a subset of what is going on- this should be true for all principle of physics - can you explain it without total reliance on mathematical formulae?
Thanks for the great comment and I totally agree with your point.
I often find that the maths stands in the way of truly understanding something, but the mathematics still plays an important part of course and there's no avoiding it.
If you have ever read "The Art of Electronics" (probably the best electronics book ever), you will find mathematics on just about every page and some of it quite daunting. That stuff should be used for reference only.
For me, teaching is about forming a picture into another person's mind that they can relate to.
Nice explanation, thank you!
Thanks. Glad you enjoyed.
Very clear, thankyou!
You are welcome!
Well done!
Thank you!
Great job!
Thank you.
Great Video 💪🏼
Thank you. Glad you found it useful.
Thank truly appreciate it
So after watching this it seems to me that this circuit, and formula would be the basis for doing phase correction. Where the resistor in the circuit would be replaced by whatever load you are attempting to phase correct for.. I would like to see a further video on this, as I realized that there may be more complication between the two reactive loads. But my first thought is that you should be able to simply sum all of the inductance, and sum all of the capacitance, and then run the equation as you have shown it.
i think the cartoon creates confusion, as voltage drops that little green guy is going to blow up like a tick
great video!!!!
Glad you liked it!!
If only this guy was my physics teacher...
Than you.
Excellent video. Well done. Towards the end I was only hoping you'd return back to the speaker example, and in a few words explain why the impedance is much higher than resistance. Is a speaker's capacitative or inductive impedance high?
Typical speakers are 4 or 8ohms impedance. The one I was demonstrating was actually a 100V Public Address speaker which incorporates a step down transformer and a DC blocking capacitor.
I agree the perfect follow on to this excellent video would be examples where we see these scenarios are played out. Speakers and other components etc
Thank you for the video, very useful but what if a capacitor is in parallel with an inductor? How calculate the impedance?
Thank you
You're welcome
Very interesting, guitar pedals often use a low value capacitor at the start of their circuits because it reduces the lower frequencies getting in. Good to learn that this is because the lower frequencies experience higher resistance
No, they don't experience lower resistance.
You said lower frequencies. Resistance applies to DC only.
Reactance is the word you are looking for.
The reactance of a capacitor in series is higher at lower frequencies.
If the cap is in parallel, it sounds like you're describing what is called a "low pass filter". If it is in series, it could be a high pass filter. If you're interested, checkout low pass, high pass and band pass filters, and you'll be building your own crossovers soon :)
@@carneeki It could even just be a capacitor to block DC. Not intended to be a filter at all.
@@deang5622 indeed, but blocking DC would definitely be a high pass filter, admittedly it would be desirable to have a low cutoff. Also, thanks to your comment I noted (and edited) an error in my original comment, so thanks!
Capacitors are commonly utilised in series to block DC in audio circuits. Provided they are reasonably sized, they will not attenuate the audible frequency range.
Good video.
Thanks for the visit, hope you keep watching. More videos coming.....
Hey, great video! Do you also have one that describes impedance in audio systems?
Thanks for the comment. The concept of impedance applies to all aspects of electronics including audio. The example measurements captured at the start of the video were in fact from a Public Address & Voice Alarm speaker.
I did publish a follow up video requested by a viewer to demonstrate an example method of measuring output impedance of a headphone jack.
czcams.com/video/HRlSZ2hJdTE/video.html
Thanks!
16:00 You actually can add the resistance, capacitive reactance & inductive reactive together just like a normal series resistance circuit - which is why they're measured in Ohms - *BUT* it's only valid for a sine wave of a specific frequency, which is the one you specify when you do the maths to calculate those reactances in the first place.
Thanks for your comment. Just so that others don't get confused by this, I thought I would clarify further.
The only time you can add resistance and reactance together is when the inductive and capacitive parts cancel each other out i.e. the inductive and capacitive reactance absolute values are equal, in which case there would be no phase angle. The Voltage and Current would be "in phase" with each other. Therefore your impedance triangle would be flat, because the length of "opposite" side would be 0.
So, unless you have zero phase shift (which is unlikely), then despite being measured in ohms, you cannot simply add the reactance and resistance together.
The specific sine wave chosen in this video was 1khz, which is commonly used in my daytime job as a PAVA engineer. 1khz is considered to be the mid range of the human hearing range and is a widely accepted test frequency for impedance measurements of audio devices (certainly when used for speech).
No you can't.
Impedance has two parts: magnitude and phase angle.
When people quote the magnitude of the impedance in ohms, they are omitting the phase angle. It is extremely common to omit the phase angle and only quote the magnitude.
To add two impedances together, or do any calculations with impedance, you need to know both the magnitude AND phase angle for the impedance.
The calculations on multiple impedances must be done using trigonometry or complex numbers.
It is not a simple case of adding the ohm values together. This is wrong.
Thanks for your video, I have a much better understanding now of Impedance.
So I'm wondering about many power adapters used today for laptops, phone chargers etc, they don't use transformers like in the old days, do they work by efectively increasing mains 230 volt frequency and then using impedance to limit the available current flow?
Thanks for the comment. Most power adaptors use fast switching circuitry to rapidly switch the supply on/off through an inductor. The output is monitored for achieving the desired voltage which regulates the rate of switching. There's normally a large capacitor on the output stage to further help maintain a stable voltage. These are known as Buck converters or switch mode supplies. Buck converters generate an output voltage lower than the input and boost converters (which work in a similar fashion) generate an output voltage higher than the supply.
@@paulpkae Ah Okay, a bit like controlling the brightness of an LED with pulse width modulation.
@@SusanAmberBruce similar yes. The output has to be regulated in some way to control the switching frequency. Inductors are capable of generating extremely high voltages.
your explanation is splendid. 1 issue though, the final formula Z^2=R^2+(Xl-Xc)^2 is not correct from a mathematical point of view as you are not exponentiating the difference of Xl and Xc but differenciating Xl^2 and Xc^2. Thus I belive the formula: Z^2=R^2+Xl^2-Xc^2 is correct. I don't want to go out as a nitpicker of your great video just think it should be out there if anyone goes out and uses the formula mentioned in the video as they will get a horrendously inacurate result :)
@maciejkoslinski2923 Thanks for your comment, but the formula in my video is indeed correct.
It's basically Pythagoras:- the square of the hypotenuse (impedance) is equal to the sum of the squares of the other two sides.
The length of the adjacent is R and the length of the opposite is Xl-Xc (Inductive Reactance minus the Capacitive Reactance).
Therefore Z^2 = R^2 + (Xl-Xc)^2.
You may have been confused about the length of the opposite side which is calculated as Xl-Xc. This is because inductive Reactance behaves the exact opposite to Capacitive Reactance. I like to think of it in a sense that when one is pushing, the other is pulling. Therefore the total "Reactance" of the circuit is Xl - Xc.
I hope this now makes more sense to you. Feel free to leave another comment if you are uncertain.
Thank you….
You're welcome.
Please do a video about level versus balanced line.
Thanks, I may do just that. Added to my list....
The physical examples were extremely helpful! One question is how could a 90 degree phase angle from impedance happen if it's the inverse tangent of (Xl-Xc) and R?
Great! Glad it helped.
@@paulpkae Sorry, I edited my comment while you replied I think. I guess my question is could voltage and amperage differ by 90 degrees or more by something other than impedance or will it never be more than 89.999- degrees out of phase?
Considering impedance as imaginary value resistors makes the reactance as a plain complex resistor, amazingly simplified with complexity!
paid lecturers at a russel group uni can't explain this topic as easily as you. bravo!
Thank you very much!
I went to a Russel Group university and mine explained is very well.
I was taught to write Xc = -1 / jwc and XL = jwl, with that writing z = R + Xc + XL and the phase angle is simply the arcTan(im / Re) where im is the imaginary part of z and Re is the real part. w = 2Pif.
This video was good for building an intuition. I missed a part where you showed how an inductor behaves with pure DC in steady state. Does it behave like a short circuit because its field is full and can't take any more energy?
Yes and inductor in DC will initially push back (when the circuit is energised), but then acts like what it is, a piece of wire. It will of course have some parasitic resistance depending on it's core size and length of the coil.
How far back in the circuit does adding capacitance or inductance affect? Does it only add these elements in until a transformer? Or is it consumed when all usable power is gone?
Good question. The answer is you have to consider the circuit as a whole.
Bear in mind that most circuits are far more complex than the simple "in series", inductor, capacitor resistor circuit I demonstrated.
Great teaching style. I got a question for the formula for the impedance: Why is the capacitve reactance lowering the total impedance? I understand that it responds the opposite way as inductive reactance to a change in frequency but is it not still adding a part to the total resistance and should therefore be still with a +? For example at low frequencies capacitive reactance is high and inductive reactance is low, but both are >0 so increasing the total reactance. Where does this "pulling factor" come from that is lowering the total impedance as shown in the impedance triangular and giving the capacitive reactance the (-) sign?
thanks a lot
Thanks for your comment. Good question
Maybe what's confusing is the fact that you are thinking of the effects of a capacitor as "resistance" which is a bit like friction. But, it is not "resistance", it is "reactance" which I refer to as an opposing force or "push back".
If you consider that the charge of a capacitor in an AC circuit can go negative (below zero, or below Ground) as well as positive, you can probably now visualise the "pulling" effect as well as the "pushing back" effect.
From an atomic perspective, the pushing and pulling effect is the attraction and repulsion of the electrons building up and then depleting.
In the simple ohms law illustration, including my additional Mr "X" guy, perhaps if I showed him repeatedly flipping to face one way then the other, then it would be a more accurate representation.
I hope this helps?
@@paulpkae yes this helps. Thank you!
Great video. Thank you.
A resistor is dissipating energy as heat.
Do inductors and capacitors dissipate energy as heat?
Thankyou.
Capacitors and Inductors actually give off very little heat. In fact, in AC circuits, its often desirable to use a capacitor, rather than a resistor to act as a current limiter.
@@paulpkae
Resistance, measured in Ohms, converts energy, delivered by current, into heat.
Reactance, measured in Ohms, does what with the energy, delivered to it through current?
I don't understand the energy balance/ energy flow. 🙂
@@rosalieroku3818 I get your point, it is confusing and difficult to explain but let me try....
Reactance is a cycle of storing and releasing energy within capacitors and/or inductors.
A capacitor charged to say 5V will push back with the same force of a 5V supply applied to it. There is no energy transferring at this point. If the capacitor was at 0V and had 5V supplied to it, it will simply start to store the charge and retain it as potential energy.
Resistors resist the current flow, much like friction in that they create a difficult path for the electrons to move through. Remember that high resistance (in Ohms) means less current and less resistance is more current and subsequently more heat.
I hope this helps.
My grandfather explained to me that the reason lightbulbs tend to fail as you turn on the light switch is that there is no inductance in the line as the circuit is completed and because of this there is more current than usual. Is that correct? And if so, is that why electronics "blow up" as power comes on after a blackout?
Good question.
In reality light bulbs will exhibit some inductance, although quite small. Passing current through any wire or electrical path will result in a degree of inductance. However, the filament within incandescent light bulbs have a relatively high resistance and its this which regulates the current running through it. I would imagine that when its left turned off for some time and allowed to cool, then there would be a surge of current at power on because the filament would be less resistive at cooler temperatures.
Ok, so then after this, how do we calculate the power factor of this circuit. Is it the cosine of 15.7 degrees? We know the apparent power is 2.2 amperes, but what is the reactive power, and what is the real power (in watts).
Hi, thanks for the comment. The calculation for power factor are quite straight forward from this point and derived from another triangle (The Power Triangle). I think this would be a great follow up video, which I will try and get produced soon.
Thanks for the idea, watch this space......
what are you doing step-volt?
but what about the speaker at the start. is that capacitive or inductive? or both?
It is both, but the combined effect is Inductive. If you pause the video at around 20seconds in, you will see the phase angle on the meter is positive (+20degrees) which means the overal load has an inductive characteristic.
Any reason why you used the inverse sin function when it appears the generally accepted function for this application is inverse tan..
No reason at all. You can utilise any trig equation that works best for you.
Lavly
My big takeaway from this is resistance is the opposing force of a component, and impedance is the opposing force of the circuit, ie all of the components combined.
I clicked on the video expecting to learn something, then through most of the video I was lost in the sauce, and then at the end thought I learned something, culminating in my first sentence.
How did I do? Did I learn something, or am I still lost?
Haha, I'm lost in your reply. What sauce are you using? :)
@@paulpkae “lost in the sauce” is a saying. It means I don’t know what is going on, and am confused by what you are talking about.
@@Linusgump haha, must be an American phrase I am not familiar with. Love it! Maybe watch some other Impedance videos that explain in a slightly different way. After watching a few variances of explaining the same thing, it usually helps.
@@paulpkae yeah, it might just be an American saying. Sorry for the confusion.
I might watch some other videos, but I watched yours because it was in my feed and I thought I would try to learn something outside of my normal interests. The extent of my electrical knowledge is to turn off the power before replacing a switch or outlet, and to call a professional for anything not complicated than that.
I’m content with that level knowledge, but it never hurts to learn something new that broadens the overall knowledge.
So. The ohm and the Volt are not true electricity Then, since the amp is the one being pushed through the narrow passage way. This would suggest that the app itself is true electricity. While the ohm and the volt are just a force.
The Ohm is NOT "electricity", but voltage is. That said, without resistance you have no voltage.
Electrical power is the combined effect of Voltage (measured in Volts) x Current (measured in Amps). So electricity is both Volts and Amps. We use Resistance/Reactance (measured in Ohms) to control the current and in turn the Voltage.
@@paulpkae Correction made.
Like for the thumbnail 😂
I always hated that image of volt pushing amp through, it should be volt on the other side taunting amp with it's middle finger :P
The middle finger is very conductive 😆
Mathematics: Z⊂R
Physics/Electronics: R∈Z!!!
In simplistic terms, I am guessing you're clarifying :- Resistance is a component of Impedance?
@13:54 "inductance is zero point two MICRO henrys" should be MILLI henrys. (or 200 miro-henrys) I would also suggest in the discussion just before that when talking about how low speed changes go through an inductor, that the slow changing doesn't relate well to the flywheel. Instead, talk about the amount of time spent in a given turning direction, and how once you're up to speed, there's effectively NO resistance, so the longer you spend going in that direction, the more time you're spending with no resistance. The "effective" inductance should be thought of as the *average* resistance over one entire cycle, so as you spend more time in one direction with a capacitor, you are spending a greater percentage of time in the high impedance behavior of the capacitor, or the longer you spend in one direction in an inductor, you are spending a greater percentage of time in the LOW impedance behavior of the inductor.
Thanks, I spotted my error between Milli and Micro soon after publishing. I did add some text but I'm not sure everyone see's it pop up because I used Subtitles to add it.
Thanks also for the alternative explanation, I am sure it will help others to visualise even better.
Vacuum ( being the Basis for electric and magnetic fields ) is an interesting "substance"...pushing and pulling charges hysteretically ( depending on charges somewhere else in space earlier ). The Quantum Nature actually defines the measured Values , especially the structure of the forces ...
kHz not KHz
uF not uf
:)
Isn’t impedance really just localized voltage differences? It doesn’t seem as fundamental as voltage, amperage or resistance. It seems like it’s just a simple derived way to look at voltage differences.
Its the combined effect of reactance (voltage difference if you like) and resistance.
impedance doesnt cause heat.
To clarify, Reactance does not cause heat, but the Resistive part of the circuit does. The Resistive element also forms part of the overall Impedance, so yes, impedance does generate heat when a current is flowing through the circuit.
@@paulpkae are u sure? it depends on your definition of impedance, isn't it when voltage is equalizing with itself to stem the flow instead of squeezing the pipe?
@@magnuswootton6181 that element is the Reactance. Impedance is the combined effect of Reactance AND Resistance. Watch the final part of the video for explanation of the Impedance triangle.
@@paulpkae ah thankyou for the clarification. reactance... doesnt cause heat. i should have said.
Thanks i dont find any of these anologies helpful because they break down right away when you limit an LEd's current, my first activity playing with electronics, and I cant get over that no one has a real explanation why they say current flows from one side or another but expreiment shows it doesnt matter. If it flowed from negative to positive then your LED should break if you put a resistor on the positive end. And im just supposed to accept this model that doesnt agree with experiment? Im still willing to believe it flows from either positive or negative and something else is going on we just dont have the resolution to see, say a few electrons get through but not enough to break the LED, then after they get resisted on the otherside they send a message to the majority comming theres resistance and they react. Maybe this is the inductance? Or all the electrons are connected somehow, so minority scout electrons up ahead can instantly send messages back to the majority. Its sort of like how lightning starts from the ground up idea. It needs a path first, but something has to scout that path right? ... Alphapheonix sort of shows this with his "path of leaste resistance" video where he shows the heat signature of electricty going through metal and i think the conclusion was some minotiry electyrons take a random path before the majority settle on the path of leaste resistance. Same could be happening with led's and resistors. But im starting to think Veritasium was onto something about electricity doesnt actually flow through wires but in the magnetic field around them.
It's because all the electrons act like a train that the caboose is connected to the engine like a ring and if there is a resistor slowing down one part of the track the whole train slows down so it doesn't matter if the resistor is before of the LED or after it because it slows the whole train (current) down
I studied physics about 15 years ago, and hence know all of this, I know all about it! They made us do all sorts of rigourous mathematical exercises involving all of this stuff - pages and pages of algebra involving complex numbers! Still cant make a circuit to save my life. Absolutely zero idea of how to put any of it into practice. Could not do electronics or electrician work to save my life. My takeaway from all of this is that the majority of education is fucking useless.
Thank you!
Thank you
You're welcome