Alternating Current

The ups and downs of Alternating Current.
Note: the video compression process makes the oscilloscope images a little strange...

Category:

Science & Technology

Tags:

• Alternating
• current
• acme
• school
• david
• stringer

[prateeksharmabittu]

wow u r awesome man !! i have a doubt . what does negative half cycle mean . if a current is movin in a particular direction on the positive half cycle does it reverse its direction or it only reverses magnitude on the negative half cycle. if magnitude reverses how can a -ve magnitude exist ??

[acmeschool]

@prateeksharmabittu

It's direction. although some days I feel negative magnitude....

[rollingroses]

how does the AC current reach destination if it keeps coming back and forth ?

[acmeschool]

well, there are several ways to think of it... The first off the top of my mind isn't great, but Imagine that you are sanding a chair rung with a long strip of sandpaper held in two hands. as you move your hands back and forth, the rung is still getting sanded. It's the movement of the electrons that does the work, not the direction that they are flowing. does that work for you?

David

[ROBATOID]

Who is this man? This looks like it was shot in the 1980's? I thought transformers step down the current?

[acmeschool]

Hi Robatoid,

Step down, yes. Turn it around, and the same transformer steps up! when volts go up, amps go down, so the voltsXamps stays constant (except for efficiency losses in the transformer)

[JettaJ1]

the four thumbs down hate science. dont worry science hates you too:)

[fizzizat]

hogwash!

[hitachi088]

@ZombiedustXXX Japan run on 110V-100V AC 50Hz.

[530BigBen]

BullShit, There are many flaws and flat out lies to this video. This is possible if every home was generating their own electricity. Because you need a substation every 2 miles to maintain a strong DC current. Laptops/anything with a battery run off DC, the converter is in the charger not in the computer, the heat from a lap top is from the integrated circuitry. Answer to the problem, Don't plug your solar panels into the grid, use it for charging batteries.

[vrjim]

@ROBATOID show is the Acme School of Stuff. Host is David Stringer

[xplorsonu]

@Serpico261 So here it is where we met last time Serpico.......it's 2 weeks ago as I can see......I was glad to see you on the other video of a Computer Organization lecture.

[Serpico261]

@xplorsonu in AC its confusing when you deal with that for the first time.

AC sine ( 0.707 ) DC sine ( 0.5 )

AC triangular ( 0,5 ) DC triangular ( 0,5 )

AC square ( 1 ) DC square ( 0,5 )

The reason why a AC square wave has a coefficient of 1 is because its negative half cycles carry a negative voltage. You have to imagine a rectified waveform, where the negative parts are made positive, so on AC square you get a straight line and therefore your Vpeak = Vrms

[Serpico261]

@xplorsonu sometimes i typed in some questions related to electrical engneering and i always found a forum that addresses these questions, i think i remember that yahoo was included.

About the clipped waveforms,take a DC triangular, sine or square wave and fill the space for one period under the voltage line and you will see that the filled space equalls the non filled space.These clipped waveforms are symmetrical and therefore you calculate 0,5 Vpeak, so yes ur right.But for AC its different

[xplorsonu]

@Serpico261  But by doing so we would be treating a clipped sine wave like a perfect square wave.......is that fair ? or may be I am mistaking somewhere.