Hi Hmblelife, You have a point. I don't know why the electric company's research material has so little to say about him. Everyone go read about Tesla on Wikipedia now. David
ahhhhh....thank you for clarity and depth and no music until the end! i just have to watch and listen to this a few more times and i'll get why AC reverses itself and why we have it instead of just DC which our gadgets use. thanks again.
I must go away and revise some of this stuff. My lack of knowledge is shocking. Or more to the point, I can't remember some of this stuff. Really really wish, I had seen this when I was back in school in the UK, but we didn't get David's brilliant explanations and demonstrations. Why, why, why not? Brilliant stuff.
Hi Hystat, Just a small correction... Acme was concieved and mapped out in a two day weekend. It was an emergency screw-up that left me with a budget, and air-time for 13 shows, but my high-tech content was nixed. I had two days to come up with a show that was low-tech. Acme is named after the toilet in my basement, seen at the beginning of the toilet show...
I have never been comfortable with the speed/force/amount analogies of volts and amps... not because I'm an expert, just because I don't have the correct gut-feeling for it. The volts are the potential for work. If you put a bucket of rocks on a table, it has more potential for work that if it's on the floor. The amps are the electrical current. Bigger=more. The volts TIMES the amperage equals the work. Transformers go either way, like gears. Maybe wikipedia can clarify. David
A two pole generator turning at 1800 RPM creates 60 Hertz. 1800 is a standard shaft rotational speed going back to the steam engine days before commercial electrical distribution. 60hz was just easy to do without changing the standards in existence when Westinghouse was starting out. They use 50 in Europe because they used a shaft speed of 1500 RPM. You will find that gas and diesel generators run at 1800 RPM.
The hot & neutral wires both carry power equally, but they don't function equally in other ways. The neutral wire is connected to earth (grounded) at each tranformer & at your electrical panel. Grounding transformers protects them from lightning. Grounding your neutral wire system protects you from the hazard created by the grounded transformers. The hot wire is connected to the main thru a circuit breaker that shuts off current if too much current starts to flow as in a short.
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)
The frequency of AC is needed to reach the proper electrical resonance, imagine someone on a swing, you push them just as they are done with the last arc, same goes for AC. Capacitors and inductors charge and discharge causing changes in the magnetic field which translates to the frequency. In the U.S. our AC's frequency is 60Hz
I've always thought 60 cycles per second was chosen because it's such a convenient number in regards to time: 60 seconds in a minute, and 60 minutes to an hour. Of course, 60Hz actually translates to one cycle every 1/60 of a second, which doesn't divide evenly (.01666666...etc...7).
5:46 - Half the square root of two. The 120V figure being advertised is RMS. 7:32 - You're describing what your fellow countryman Mehdi Sadaghdar knows as a *full bridge rectifier!*
Hi Dave. An old issue Invention & Tech re:strangest job ever. Switch gears etc in. Clocks so when Los Angeles changes from 50 to 60 cps they’ll keep time. Still don’t know why- cy ...
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
hey i have a electricity-related exam for school in a few days. can somebody please explain to me why in an AC generator the output voltage is negative-positive-negative-positive
1:11 The work that's done by the current IS NOT measured in watts, but in joules. (watt hours) It's the energy that you consume, because the work is the energy in transfer. BTW, that determines how much you pay for your electricity bills.
Did you plug your oscilloscope directly into wall, I was told this was safe did it and blew a breaker in my house?, says its rated for 10kv, the scope was also connected in parallel with a motor to act as a load, i did it both ways direct and in parallel?
What jerk said it was safe to plug a line-powered 'scope into the wall? The ground terminal of a scope probe is connected to the chassis of the 'scope and from there to the U-ground of our AC outlet. You must have put your probe ground to the hot wire? Even if you put your ground on the neutral, that's not safe, either. You should use an isolation transformer and put your scope on the secondary windings.
Maybe they chose 60 because thats what the average human eye refresh rate is at, or at least thats what I've heard. Would keep the lights from flickering visibly to the human eye.
great video, but i wish you gave tesla credit! everyone look up nikola tesla, hes responsible for ac power, xray , florecent bulbs, radio, wireless power transfer, even basic logic circuits which lead to your computers and cell phones. the list goes on and on!
The 60 comes from the fact that the UK uses 50 and not being happy at being the same the americans went 10 better..... However when the UK realised this we doubled our voltage.
The current doesn't switch 120 times per sec. That's just the voltage needed to push the current through different devices. The bigger the device your trying to run, the more voltage is needed to push the current through it. In other countries 240 volts is used to run there machinery, but the frequency is still the same. It's either 50Hz or 60Hz current witch gives 3000-3600 RPMs and if you divide by 60 you get the frequency per sec.
The number 60 comes from the man who invented Alternating Current. Nikola Tesla. 60hz current means the poles in the magnetized coils are switching polarity's 60 times in 1 second. On that note there is an interesting fact that happens with 60 Hz current and also happens driving your car. If your moving at 60 MPH the car somehow reaches a point where it gets the same amount of Horse power out V.S the Horse Power being put into the motor. The same effect happens with AC electricity...
We know why we have 60Hz (or here in Europe 50Hz). It was calculated to be 2 times more than your eye can see fluently (about 25-30Hz). 60Hz is also ideal for most of the appliances in your home. For example ac electric motors. In switched-mode power supply you increase the frequency up to several kHz (20-30) and you can use much smaller transformers.
The "invention" the electrical transformer is attributable to several scientists, many of whom predated Tesla. The modern transformer as an engineering designed object can be fairly attributed to the team of several engineers working under the direction of George Westinghouse. The transformer itself is more his invention (to the extent that it belongs to any one person) than Teslas.
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Hi Hmblelife,
You have a point. I don't know why the electric company's research material has so little to say about him. Everyone go read about Tesla on Wikipedia now.
David
ahhhhh....thank you for clarity and depth and no music until the end! i just have to watch and listen to this a few more times and i'll get why AC reverses itself and why we have it instead of just DC which our gadgets use. thanks again.
This whole Acme series was produced in a 2 day weekend. David is "winging it"...
Modern day, so called educational channels should be ashamed
He has a REALLY nice mains sinus wave! I have NEVER EVER seen any that smooth!
I must go away and revise some of this stuff. My lack of knowledge is shocking. Or more to the point, I can't remember some of this stuff. Really really wish, I had seen this when I was back in school in the UK, but we didn't get David's brilliant explanations and demonstrations. Why, why, why not? Brilliant stuff.
Hi Hystat,
Just a small correction... Acme was concieved and mapped out in a two day weekend. It was an emergency screw-up that left me with a budget, and air-time for 13 shows, but my high-tech content was nixed. I had two days to come up with a show that was low-tech. Acme is named after the toilet in my basement, seen at the beginning of the toilet show...
7:55 of airtime most expertly filled.
THX David!
Thank you for uploading this video , my concepts became clear after watching this
I agree, Tesla doesn't get enough credit and this is one of the most informative videos I have seen about electricity
I have never been comfortable with the speed/force/amount analogies of volts and amps... not because I'm an expert, just because I don't have the correct gut-feeling for it. The volts are the potential for work. If you put a bucket of rocks on a table, it has more potential for work that if it's on the floor. The amps are the electrical current. Bigger=more. The volts TIMES the amperage equals the work.
Transformers go either way, like gears.
Maybe wikipedia can clarify.
David
These is an awesome video. Great job!
A two pole generator turning at 1800 RPM creates 60 Hertz. 1800 is a standard shaft rotational speed going back to the steam engine days before commercial electrical distribution. 60hz was just easy to do without changing the standards in existence when Westinghouse was starting out. They use 50 in Europe because they used a shaft speed of 1500 RPM. You will find that gas and diesel generators run at 1800 RPM.
wow, real knowledge
Great Work, you Just made Chapter 6 in Modern Refrigeration and Air Conditioning for me.
7 people are mad because they didn't hear him say transformer before he said Westinghouse. Look it up.
The hot & neutral wires both carry power equally, but they don't function equally in other ways. The neutral wire is connected to earth (grounded) at each tranformer & at your electrical panel. Grounding transformers protects them from lightning. Grounding your neutral wire system protects you from the hazard created by the grounded transformers. The hot wire is connected to the main thru a circuit breaker that shuts off current if too much current starts to flow as in a short.
THIS WAS GREAT. U MY BOY
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)
The frequency of AC is needed to reach the proper electrical resonance, imagine someone on a swing, you push them just as they are done with the last arc, same goes for AC. Capacitors and inductors charge and discharge causing changes in the magnetic field which translates to the frequency. In the U.S. our AC's frequency is 60Hz
I've always thought 60 cycles per second was chosen because it's such a convenient number in regards to time: 60 seconds in a minute, and 60 minutes to an hour. Of course, 60Hz actually translates to one cycle every 1/60 of a second, which doesn't divide evenly (.01666666...etc...7).
5:46 - Half the square root of two. The 120V figure being advertised is RMS.
7:32 - You're describing what your fellow countryman Mehdi Sadaghdar knows as a *full bridge rectifier!*
The 60 [or 50 where I live] has to do with the RPM of the Alternator
What an awesome video.
Hi Dave. An old issue Invention & Tech re:strangest job ever. Switch gears etc in. Clocks so when Los Angeles changes from 50 to 60 cps they’ll keep time. Still don’t know why- cy ...
nice. about time someone puts up a video that makes since and isnt filmed by grandpa flanders.
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
hey i have a electricity-related exam for school in a few days. can somebody please explain to me why in an AC generator the output voltage is negative-positive-negative-positive
0.707 comes from square root of 2. because of the concept of root mean squared
Isn't the filament in a light bulb and the electric stove a type of resistor?
Yes, it is. It is the load in the circuit. Without a load, you have a very destructive short circuit.
1:11
The work that's done by the current IS NOT measured in watts, but in joules. (watt hours) It's the energy that you consume, because the work is the energy in transfer. BTW, that determines how much you pay for your electricity bills.
Wow.. man... I'm jealous.. you have so many equipments... :D
@prateeksharmabittu
It's direction. although some days I feel negative magnitude....
@PAM2167 one side steps up one side steps down, can be used either way
Did you plug your oscilloscope directly into wall, I was told this was safe did it and blew a breaker in my house?, says its rated for 10kv, the scope was also connected in parallel with a motor to act as a load, i did it both ways direct and in parallel?
What jerk said it was safe to plug a line-powered 'scope into the wall? The ground terminal of a scope probe is connected to the chassis of the 'scope and from there to the U-ground of our AC outlet. You must have put your probe ground to the hot wire? Even if you put your ground on the neutral, that's not safe, either. You should use an isolation transformer and put your scope on the secondary windings.
the 60 is the speed measured in hz. hertz is the frequency ..or the reciprocal of the period.T=1/f......(I think im right at least)
thank you! this helps me understand it so much better!
and I probably should give a shout out of thanks to Tesla too :D
Maybe they chose 60 because thats what the average human eye refresh rate is at, or at least thats what I've heard. Would keep the lights from flickering visibly to the human eye.
That was cool !!
George Westinghouse invented XFMRs?! I thought Nicoli Tesla invented transformers and Westinghouse was his investor/ patron competing with Edison.
6:09 what happened there? Why did the graph change?
great video, but i wish you gave tesla credit! everyone look up nikola tesla, hes responsible for ac power, xray , florecent bulbs, radio, wireless power transfer, even basic logic circuits which lead to your computers and cell phones. the list goes on and on!
best explain ever
well AC doesn`t change direction until it first reaches the positive terminal.
Great ticher
thanks
The 60 comes from the fact that the UK uses 50 and not being happy at being the same the americans went 10 better..... However when the UK realised this we doubled our voltage.
Great
Seven people don't get alternating current.
WHY THE .707???????
and how to create AC out of DC?
Use an inverter.
Doesn't matter Nikola Tesla was the Inventor.
The current doesn't switch 120 times per sec. That's just the voltage needed to push the current through different devices. The bigger the device your trying to run, the more voltage is needed to push the current through it. In other countries 240 volts is used to run there machinery, but the frequency is still the same. It's either 50Hz or 60Hz current witch gives 3000-3600 RPMs and if you divide by 60 you get the frequency per sec.
60 cicles are maybe random ..in europe...atleast in serbi... its 50 Hz
the 60 Hz comes from Nicholas Tesla.
nice
C'mon David hands down.
In the early 30’s
The number 60 comes from the man who invented Alternating Current. Nikola Tesla. 60hz current means the poles in the magnetized coils are switching polarity's 60 times in 1 second. On that note there is an interesting fact that happens with 60 Hz current and also happens driving your car. If your moving at 60 MPH the car somehow reaches a point where it gets the same amount of Horse power out V.S the Horse Power being put into the motor. The same effect happens with AC electricity...
cool
@mikero1369 no 60 times in a second.
do elaborate
the sin of 45 is not .707. 0.707 is half the square root of 2 , which i remember using for some calculutions to get RMS or VMAX
But it is the sine of 45°.
tesla should still be credited
Hi Sir, how can I download this video. It's really interesting.
We know why we have 60Hz (or here in Europe 50Hz). It was calculated to be 2 times more than your eye can see fluently (about 25-30Hz). 60Hz is also ideal for most of the appliances in your home. For example ac electric motors. In switched-mode power supply you increase the frequency up to several kHz (20-30) and you can use much smaller transformers.
@ROBATOID step up or step down
So you want to know why they chose 60!?! Why? You got a problem with 60!?! Did 60 do anything to you!?! LEAVE 60 ALONE!!!
"🇭o🇬w🇦s🇭!"
Very shocking
George Westinghouse? Shame on you, Nikola Tesla invented this.
The "invention" the electrical transformer is attributable to several scientists, many of whom predated Tesla. The modern transformer as an engineering designed object can be fairly attributed to the team of several engineers working under the direction of George Westinghouse. The transformer itself is more his invention (to the extent that it belongs to any one person) than Teslas.
tesla, tesla, tesla, pssst,
tesla
60 seconds in a minute.
hogwash!
I don't like this guy I don't know why? he seems cocky.