RMS Voltage Equation Then the RMS voltage (VRMS) of a sinusoidal waveform is determined by multiplying the peak voltage value by 0.7071, which is the same as one divided by the square root of two ( 1/√2 ).
That's right: Vrms = Vpeak / sqrt(2). But it is only valid for sine waves. The information that Vrms is always smaller than Vpeak is wrong. In a square wave, Vrms = Vpeak. And at 3:41, the chart is wrong. In Brazil we have a mix of 220V and 127V both at 60Hz. Major cities here like Rio de Janeiro and São Paulo uses 127V.
Love the shirt. The graphics are amazing as usual. I have no idea what the cartoon insert meant. I heard, "far apart," which I transmorgrified into "high frequency power transmission lines..." but... that's a stretch? There's also something wrong with the focus. You'll notice at 5:14 that the subject is blurry, but the items in back are in focus. Perhaps the camera is being confused by items in the path of the attempted focus? The person, or item, should be the first thing the focus seeking hits, for youtube vids usually.
I think the video should have focused just on the "power" aspect of AC/DC and that AC for transmitting power really needs to be a sinus wave to work well with transformers (and get the same wave on the output). Mixing signal transmission just confused things a lot, we are rarely focused on the "C" for "current" in "AC" when talking about signals... another indication that "AC" is misused for signals is that "DC" for signals makes no sense. The reason why we use transformers to increase voltage for the long distance transport seems to be missing (power is voltage times current and losses are proportional to current squared, so we reduce current and boost voltage)...
@@TanjoGalbi :) Good catch. Sinus is the latin word sine was derived from (and still seen in English in e.g. in "sinusoidal"). So sounded OK to me at first :)
At positive half cycle, current flows from phase(line) to neutral following the path from higher potential to lower. You put a voltage tester on line, it will beep, on neutral, it wont. At negative half cycle the phase potential is lower than neutral so current flows in the other direction. So line becomes neutral and neutral becomes line. But, do you mean that we have supply in neutral during negative half cycle? In this case, why a line tester would fail to glow if it is tested over neutral line at the negative half cycle. Please explain.
Good evening, i noticed that the alternative current in the circuit, the L E D was without diode, which is in my knowledge the led wont work in A C current or i am wrong , please advise. Thanks ( in general I like her speech and knowledge of electronics)
Wow you do such an amazing jobs at explaining stuff. It helped with a lot of my questions and then some. Thanks a lot keep up the good work. I'm subscribing
i find dc sort of easy Kind of tho since it has + and - Wire eks Red(+) Black (-). but ac has L(Live) and N(Neutral) and if i connect them together the Circuit braker gets trigged, but when L and N are Shorted via Light bulp(E27) as a example or Wolfram steel(i think its that) Heater that common over the door as a Heater then it works ok wiht out Trigging the Circuit Braker, Perhaps a video about this stuff to, also L and N gets connected to together on the Primary side of Transformator :D Great video as Always :)
Great video Karen. I think a few sub topics can be added to this video to compliment what was explained. When comparing AC versus DC, it might be helpful to explain why AC is used to distribute being if we used DC, the size of the power lines would be much bigger to than what is used for AC. This of course goes back to the early 19th century, so maybe a quick history lesson is in order. Also, maybe including some applications as to why 3-phase AC is important. Maybe briefly explaining how some electric motors have issues using a single phase followed by showing a graph of the 3-phase current while explaining that they are 120 degree out of phase of each other (2.09 rad). I'm not sure if you would want to also include a substitute to a permanent magnet being an electro-magnet since you briefly talk about topics that could lead to a short explanation of this alternative. I understand if you try and generally cover everything, this video could become very long so in the interest of keeping it short, a lot is left out and explained in other videos.
A very good description of Alternating Current vs Direct Current. Now to get that Out of Phase aspect addressed....compliments of the UK band Pitchshifter :D
Lost me in the first few seconds when you said the power goes both ways. I just don't understand how that works. I don't even understand for something even as basic as traveling through the power lines. If it is going both directions then how does it travel even? And I'm COMPLETELY baffled by the idea of it traveling both directions in a circuit. To me circuits seem kind of like programs in a way. Each part does something that the next part works off from. However, if power is traveling back and forth then that would be like having to write programs that work if you ran them backwards. That just seems EXTREMELY limited on what you could do. Unless you are turning it into DC power for most circuits. However, doesn't that waste a lot of energy? I'm sure it all makes sense, otherwise we wouldn't do it. Your explanation though just created more questions for me than it answered.
Positive side peak * .707 = 120, same for negative. Both show 170 * .707 to give you 120v useable per peak. You can also take the rms * 1.414 to get a peak voltage (not peak to peak). 120v * 1.414 = 170v
Appropriate shirt for this video! Ty you for the video. AC/DC
RMS Voltage Equation
Then the RMS voltage (VRMS) of a sinusoidal waveform is determined by multiplying the peak voltage value by 0.7071, which is the same as one divided by the square root of two ( 1/√2 ).
1/✓2=✓2/2
@@abdelbaki4512 yes is does
Hi in minute 2:36 is wrong explanation, VRMS = VPEAK / SQRT(2), or if I am wrong correct me :)
That's right: Vrms = Vpeak / sqrt(2). But it is only valid for sine waves. The information that Vrms is always smaller than Vpeak is wrong. In a square wave, Vrms = Vpeak.
And at 3:41, the chart is wrong. In Brazil we have a mix of 220V and 127V both at 60Hz. Major cities here like Rio de Janeiro and São Paulo uses 127V.
I just learned this in my electricity class. √2 is ≈1.4 so it's very easy to see it would be bigger than peak voltage
RMS = PEAK X THE RECICICAL OF THE SUARE ROOT OF 2
@@henryrobinson9837 only for sine waves. More information can be found on wikipedia:
en.wikipedia.org/wiki/Root_mean_square#In_common_waveforms
Karen, its a excellent video, regarding the alternating current. All the best.
Love the shirt. The graphics are amazing as usual. I have no idea what the cartoon insert meant. I heard, "far apart," which I transmorgrified into "high frequency power transmission lines..." but... that's a stretch? There's also something wrong with the focus. You'll notice at 5:14 that the subject is blurry, but the items in back are in focus. Perhaps the camera is being confused by items in the path of the attempted focus? The person, or item, should be the first thing the focus seeking hits, for youtube vids usually.
the hertz measure the rotation speed in the alternator's rotor?
Can someone tell me what the stair like symbol next to the diode symbol is? And what is the her symbol too?
I think the video should have focused just on the "power" aspect of AC/DC and that AC for transmitting power really needs to be a sinus wave to work well with transformers (and get the same wave on the output). Mixing signal transmission just confused things a lot, we are rarely focused on the "C" for "current" in "AC" when talking about signals... another indication that "AC" is misused for signals is that "DC" for signals makes no sense.
The reason why we use transformers to increase voltage for the long distance transport seems to be missing (power is voltage times current and losses are proportional to current squared, so we reduce current and boost voltage)...
I'm sorry but "sinus wave" really made me laugh! 🤣
It is "sine wave", sinus is to do with the nasal system (your nose). 🙂
@@TanjoGalbi :) Good catch. Sinus is the latin word sine was derived from (and still seen in English in e.g. in "sinusoidal"). So sounded OK to me at first :)
At positive half cycle, current flows from phase(line) to neutral following the path from higher potential to lower. You put a voltage tester on line, it will beep, on neutral, it wont.
At negative half cycle the phase potential is lower than neutral so current flows in the other direction. So line becomes neutral and neutral becomes line.
But, do you mean that we have supply in neutral during negative half cycle? In this case, why a line tester would fail to glow if it is tested over neutral line at the negative half cycle.
Please explain.
Love your shirt, big AC/DC fan my self. Works for me with the Video too. Great video
This series is very helpful for novices like me. Thank you!
Good evening, i noticed that the alternative current in the circuit, the L E D was without diode, which is in my knowledge the led wont work in A C current or i am wrong , please advise. Thanks ( in general I like her speech and knowledge of electronics)
THANKS a lot for all your vids...all of them are AWESOME!!!
Can someone tell my what the neutral wire is for or point me in the direction of a video that explains it’s purpose. Thanks I’m advance
Very good video and very informative.
Guys can anyone tell me what happened to the yourube channel the learning circuit
I cant find it
"Peak to peak" value - I don't think it was properly used here... :-/ According to the terms used, peek-to-peek voltage in US is 2*170=340V.
Ooh, shiny! I see the Firefly figures in the back!
Wow you do such an amazing jobs at explaining stuff. It helped with a lot of my questions and then some. Thanks a lot keep up the good work. I'm subscribing
i find dc sort of easy Kind of tho since it has + and - Wire eks Red(+) Black (-). but ac has L(Live) and N(Neutral) and if i connect them together the Circuit braker gets trigged, but when L and N are Shorted via Light bulp(E27) as a example or Wolfram steel(i think its that) Heater that common over the door as a Heater then it works ok wiht out Trigging the Circuit Braker, Perhaps a video about this stuff to, also L and N gets connected to together on the Primary side of Transformator :D Great video as Always :)
Very informative. I still struggle understanding the physics of AC power (beyond the basics), like what the electrons are actually doing etc
1:21 AC cannot flow through a diode like that. New kind of diode?
The V_RMS equation should have the peak voltage multiplied by √ 2 / 2, not just √ 2 to get ~0.707
Big shout out to the late Nikola Tesla for giving AC to humanity. He doesn't get enough credit for the great guy he was.
Thanks... 👌
Finally I understand heat and electricity.
Heat is movement of atoms
Electricity is movement of electrons.
Now what is light? 🤔
Photons
That equation for Vrms is only valid for sine waves, by the way.
Great video Karen. I think a few sub topics can be added to this video to compliment what was explained. When comparing AC versus DC, it might be helpful to explain why AC is used to distribute being if we used DC, the size of the power lines would be much bigger to than what is used for AC. This of course goes back to the early 19th century, so maybe a quick history lesson is in order. Also, maybe including some applications as to why 3-phase AC is important. Maybe briefly explaining how some electric motors have issues using a single phase followed by showing a graph of the 3-phase current while explaining that they are 120 degree out of phase of each other (2.09 rad). I'm not sure if you would want to also include a substitute to a permanent magnet being an electro-magnet since you briefly talk about topics that could lead to a short explanation of this alternative. I understand if you try and generally cover everything, this video could become very long so in the interest of keeping it short, a lot is left out and explained in other videos.
A very good description of Alternating Current vs Direct Current. Now to get that Out of Phase aspect addressed....compliments of the UK band Pitchshifter :D
Lost me in the first few seconds when you said the power goes both ways. I just don't understand how that works. I don't even understand for something even as basic as traveling through the power lines. If it is going both directions then how does it travel even? And I'm COMPLETELY baffled by the idea of it traveling both directions in a circuit. To me circuits seem kind of like programs in a way. Each part does something that the next part works off from. However, if power is traveling back and forth then that would be like having to write programs that work if you ran them backwards. That just seems EXTREMELY limited on what you could do. Unless you are turning it into DC power for most circuits. However, doesn't that waste a lot of energy? I'm sure it all makes sense, otherwise we wouldn't do it. Your explanation though just created more questions for me than it answered.
Actually, 120v is the "nominal" voltage it's not absolute and is only the rms values in a 100% efficient perfect world lol
Someone told me AC is converted to DC on modern day refrigerators, is it true, if true then why?
If AC is either 50 or 60 Hz then how is it possible that TV can display more than 50 or 60 fps! e.g 100 Hz 🤯
Hfe symbol too
I am having a hard time understanding how you get .707 from the square root of 2.
I think I am missing something.
She should of done 240/1.4 which is square root of two which equals 170, which is equivalent to doing 240*0.7
Positive side peak * .707 = 120, same for negative. Both show 170 * .707 to give you 120v useable per peak. You can also take the rms * 1.414 to get a peak voltage (not peak to peak). 120v * 1.414 = 170v
ITS 1 DIVIDED BY THE SGUARE ROOT OF 2=RMS
It alternates
RMS calculation is wrong. Lots of incorrect information. Would fail electrical homework assignment. This needs to be fact checked.