HVAC school introduces you to Frequency & Sine 101. Some easy ways to wrap your head around alternating current, electromagnetism, frequency, wave length and sine. Featuring Bryan Orr.
Read all the tech tips, take the quizzes
and find our handy calculators at https://www.hvacrschool.com/
Read all the tech tips, take the quizzes
and find our handy calculators at https://www.hvacrschool.com/
All right, so I wanted to do a quick video on frequency, which relates to alternating current, obviously direct current. We don't have frequency, but this is one of the most misunderstood portions of electrical theory, and I really don't even want to do theory. Instead, I want to talk about the practical side of this and and kind of being able to, hopefully, by the end of this short video kind of get a vision of what's going on when we talk about alternating current, when you see things like a sine wave, I was sharing some images of an oscilloscope and to show compressor starting and capacitors and a lot of people. You know responded back that that they were having a hard time, even understanding what they were seeing.
So I thought well, it might be useful to have some of this knowledge and it might give you a better picture in your head and I did a lot of training on this in Haiti with little kids, and I found some metaphors that I think worked pretty Good and it's actually helped clarify some of it in my mind as well. So let's go over this you've all seen a sine wave that looks like this. You know it kind of goes up and down like this and maybe you're confused about what that means. Electricity is going back and forth or up and down, but truthfully well.
The way this really works is is that it's being generated in a rotational magnetic field. So when we talk about electromagnetism, electromagnetism is a way of essentially explaining that electricity and magnetism are related. So magnetism can generate current flow. Electron flow and electron flow can create magnetism.
When we talk about things like radio waves or microwaves or whatever, we'll just call it called electromagnetic field, because they're so closely related to each other. But when we talked you know about generating electricity in an alternating sine wave like this, what we're really doing is we're spinning an electromagnet and that electromagnetic field, that's spinning, is generating electricity without going into you know the theory of generators and all that, it's just you Know it's important to kind of notice that it's a rotational field and that rotational field represented on a time line. So if you take this and you stretch it out in time, you know left to right represents time here. That circle then becomes this sine wave.
Instead of being a circle, that's kind of continuously going around, it becomes a sine wave because it's on a time line. So this circle is this sine wave and for me, as soon as I started, thinking of electromagnetism or alternating current as a rotational field, that made it a lot easier for me to sort of understand what I'm seeing when I'm looking at a sine wave. So this is an image that we created for our Haiti training and we had it all the words, of course, we're translated in Haitian Creole. But I think this is a really good way of thinking about this, because when you think about kids using a jump, rope they're not just moving their arm up and down, although they you know they could be in this case, they could just be moving it up And down, but if you think of a traditional jump, rope, you're, spinning it and as you're spinning it. If you were to look at it from the side, you wouldn't see the spinning, you would just see it going up and down and you would think. Okay, it's just going up and down, but in reality, when kids are using a jump, rope and they're rotating their hand. It creates this sort of shape, but it's happening in a rotational way, and that, for me, is a good way to envision a sine wave. Thinking of it more in 3d, like using a jump rope and how that creates that up-and-down.
Now again, that's a metaphor: it's not perfect, but it's a good way for me to think about it and if they move in this case, if you think of it, just like they're moving their hands up and down if they do it more slowly than the wave Length is longer so lower frequency is gon na create a longer wave length and if they do it more rapidly and then the wave length is going to shorten so the distance between the waves is gon na shorten because the frequency increases so they're doing it more Frequently, which shortens the wave lengths and if you you know, put time in there, you're gon na have more peaks and valleys per time unit, so per second per minute whatever. So, when you think of you know, 60 Hertz, for example, that's 60 cycles per second! That's what we see in the US and in Europe and other places you see, 50 Hertz, and so, if you have more cycles more circles more times that that motor goes around or that generator I should say, moves around, then that shortens the frequency and also increases The wave length so wave length is more something that we talk about in electromagnetics. You know: radio, waves, microwaves, gamma waves, all those sorts of things that actually travel through the air, but even in electricity we can think of wavelength. If we hang on a variable, frequency drive, for example, and you were tracking it on an oscilloscope if, as the frequency goes up, the wavelength, the distance between the waves is going to shorten, and so that's a higher frequency.
Higher frequency is also a shorter wavelength, and a lower frequency is a longer wavelength. This applies to things like like. We talked about electricity, electromagnetic waves that go through the air and then also it applies to sound. So we see this and sound even an audio recording.
If I die when we edit audio, when you look at lower wavelengths, those are the deeper more bassy sounds and then the higher pitch sounds are closer together wavelengths, but it all comes down to frequency. How frequently does it go up and down or more accurately, how frequently does it rotate when we're talking about electrical generation? To me, that's a good way of thinking about that and using this sort of metaphor of either kids jumping rope or them kind of shaking a rope up and down in between their hands to me just help clarify a lot of it. That may be something you can use for yourself or maybe, when you're educating somebody and then also I want to just talk a little bit about electro magnetics. I think it's, it's kind of cool that when we think of frequency you know frequency exists in nature. To be longer a wavelength, the more it's the things that we deal with like radio waves and then, as you go up into the higher and higher frequencies you get into microwaves, infrared and then visible light is just in this very, very fine band with the frequency And then you go into x-rays and other things, but they're all really the same thing, they're all electromagnetism. What distinguishes them from each other is that band width. You know we talk about band width or we talk about. You know maybe tuning in a radio or tuning in an old-school television yeah, and these are analog signals.
These aren't visual. You know digital is completely different, but old school analog signals. You were really tuning in to a resonant frequency. So if you think about, inter tuning an old-school radio like this one, you're literally tuning that radio to the same frequency in megahertz and again that's a much much higher frequency than what we see, electricity is 60 Hertz.
So 60 cycles per second, where this is a hundred an example where we have tuned in here. I think it's a hundred thousand Hertz so like I think this would be we can make it heard is a thousand. So I think this would be a hundred thousand cycles. I'm not gon na even try to edit this out, because the fact is, it doesn't matter to HVAC, but it's much much higher frequency and when we tune in our radio to that frequency, we are we're resonating with that frequency and so then it starts it plays Out of our out of our radio, it's really interesting when you think about it, how things like light and radio waves and microwaves and all these things are all really the same basic thing: it's it's electromagnetic energy, but it's just tuned to different frequencies, so we use Frequencies, in so many different ways, I think it's kind of cool, just a cool little thing to know, and it kind of helps broaden your imagination a little bit, but as far as it relates to things like electric motors.
I think this metaphor and thinking about short and longer wavelengths low-frequency, creating a longer wavelength, higher frequency, creating a shorter wavelength and also thinking about it in terms of a rotational in the case of electricity motors things like that, and then we just represent that on a Time line and that's why it looks like a sine wave that to me makes a lot more sense and kind of nails that down in my head, of course, from a practical standpoint, there's a lot more things we would need to talk about, but just to sort Of imagine what you're, seeing when you're looking at a sine wave, whether this sine wave represents voltage or amperage, no matter what it represents. It just makes sense that it's going up and down because it's being generated circularly, you know again, like the two kids jumping rope. There you go. There is some frequency basics. Hopefully you find that helpful and thank you for watching all of our videos we'll see you next time.
I watch your videos, podcast, emails. You are marketing to a simple mind I understand but you need to start with the fundamentals not jump to the middle then go to the start then to the end. Not my type of learning even though it might work for most people.
Oh no I never thought 3D but I think you are on to it, like a dynamic pulse. Cool running with it. A sphere of charge. Humm liking it.
honestly thank you so much for doing this. i started online college for HVAC and i couldn't for the life of me figure out how to fix anything based off of that book. ive learned so much more thru these videos past 7 videos than i have in over 200 pages of a text book. its way easier to pay attention when you see what your supposed to be doing or at least the pictures of what it is your talking about so im not completely lost and if theres something you dont understand you can easily google it and come right back and be right on track so thank you so much!!
See in 3D. It’s a vortex💯😎
Thank god I stopped in. Got it. Everybody always thought the wave form was a flat plane. Now we know. Same form as a screw. Very enlightening. Service area Orleans??
Thank you!! 👍
Nice one.