how does AC power work?
if i understand it correctly, there is a period of no voltage 60 times a second. does that mean that things plugged into the wall have spikes of electricity periodically?
I mean, I get DC power, electricity is constant and does what it should the whole time. but what the fuck does negative voltage mean? how can power be transmitted if its negative, or zero voltage? is power only transmitted during the positive part of the sine wave?
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120V DC would fry most household appliances quite summarily. With AC you are having A pushed through the circuit in controlled doses, then your V continues back through the Neutral wire to keep the A flowing instead of having a constant lightning volt to your phone while you charge it.
Maybe look to the accredited original inventors of AC, at their inventions...
Tesla
Ottó Bláthy
sure, 120v DC is too much power. but you could reduce it and it would work fine, IE: 12v motors, things like that.
do all devices have some sort of AC to DC converter inside them to make them run on DC? or are most things capable of utilizing AC power?
I don't understand what exactly negative voltage means. I get that in a DC circuit, electricity flows in one direction the whole time, but in an AC circuit does the electricity actually flow the opposite way half the time? and periodically not flow at all?
how the fuck can you utilize that? say for like, a TV, or an oven, or microwave. surely these things need constant power to do what they do.
no this is wrong.
think of like water flow; DC is like a hose thats been turned on just enough to make the beam of water support itself. AC like you've taken that same hose on that same speed but you've pushed your finger over the end. its the same amount of power but its just traveling faster. thats what I learnt in school any ways.
but it's not constant. that's the whole thing about AC. the current alternates from positive to negative.
...If you meant to ask why is AC mainly used in long range current transmission, I suggest reading about:
Resonance, and how it relates to AC
if not trolling, pure autism.
Are you literally this stupid or are you trolling. I need to know for science
no. i can accept that AC is acceptable for long range uses. there is less power loss over long distances.
i've taken three physics courses, and have some knowledge of electronics, but all in terms of DC power.
Holy fuck, don't read this OP
go to /diy/ ask the hamfags you'll fir right in puffr
Voltage indicates a potential. It is how much electrons within the wire are inclined to move. Movement of electrons is what we call electricity. Negative voltage simply means that the electrons are inclined to move towards the other direction. There is still power because there is still movement of electrons.
how does a generator make AC power? wouldn't winding a motor by hand only create DC power?
obviously. I didn't think that I would need to include that because its in the bloody name. most houses use AC because its just more convenient to send AC over vast distance due to the speed that it travels. the current doesn't flicker on and off really fast, its more fluid.
It's true that the voltage is periodically off 60 times a second. Negative voltage/current only means the electricity is flowing in the opposite direction. You can still extract power from it.
AC power can be useful in some applications, for instance, electromagnetic induction where a variable current induces a magnetic field which you can use to power a motor. Look up induction motors.
>This
With AC it doesn't matter the direction of the current. It'll alternate direction many times each second.
what is literally?
The 'frame rate' of the eyes isn't high enough to see a light source pulse at 60hz, so we perceive it as being constantly on, though it isn't always on with AC, it does continue to glow.
It's what the standard of 50-60hz was designed for.
how can you transmit power in that case? do the electrons have any net movement?
say you have dc power going through 100 feet of wire, you literally have electrons at one end going to the other end eventually.
in AC, do the electrons just jostle back and forth, and sort of push and pull adjacent electrons at the same time? with no net flow of electrons?
No. rotating a motor will create AC current. The magnets will constantly change the way that the electrons travel. The DC generators need the use of special parts to insure that the current doesn't "go back". This has the problem that the system overheats and you lose more energy in the form of heat.
is that actually the case? like a lightbulb being powered with AC-- it's on when positive voltage is applied, and on when negative voltage is applied, and off when it's zero?
if you recorded an old school filament lightbulb with a high speed camera, would you see this?
Negative isn't negative, it's reverse. Goes in the opposite direction. Alternating current means 1/50 of a second, it goes one way, the voltage drops and then increases the other way. Etcetera....
Did you just call an incandescent lightbulb "old school"
yeah check it out
youtube.com
Because every metal has what is known as electron cloud. It's easier to make the atoms share their e- and have those little fuckers jumping back and forth than forcing them to traven in one direction.
DC energy loses quickly their charge in the form of heat. This is why we use AC instead of DC.
>y, those are $0?
Fuck you, nobody will by your shitty products.
Voltage is another term for potential difference. The voltage swings from 110v positive to negative.... but is always referenced to neutral which is zero.
There is 110 volts difference at the top and bottom of the cycle. Well it's 110 RMS but the concept is accurate
This is correct.
Building on that, AC is what's served in the walls because less power is lost in long distance power lines when using AC than DC. If I'm not mistaken, it's also easier to build generators that make AC.
However most of our end use devices do use DC. The wall power adapters use electromagnetism to reduce the voltage from the huge 120 volt ac to a smaller value, but it's still AC.
The power adapters then use diodes which act as electricity one way valves to turn the AC into DC.
In a nutshell.
FWIW newfags electrons don't go rushing down a conductor at the speed of light. It's an electromagnetic wave. Electrons have the same particle / wave duality as photons.
Individual electrons move at a snails pace. Literally.
if this is actually the case, then I get it.
if most "consumer devices" utilize DC current for circuits and things, and AC is just used to transmit power, I can accept that reality.
yeah I can understand that. I understand electrons and electron holes in the sense of moving electricity. is that to say that in a power transmission line, there is no net movement of electrons, but rather a forward and backwards oscillation through the entire length of the wire?
You are thinking small appliances. Electronica. PlayStations and laptops use DC.
Most of the power in the world is burnt in mains voltage AC appliances - air con, heating, toasters, kettles, ovens, fridges... lighting.
What are you, a 1st grade kid? Fuck off seriously.
The voltage/EMF is a field, inside the wire, whereas the CURRENT is electrons flowing, retard. They travel fast, but not at c.
Individual electrons don't 'flow' at any kind of speed. You would throw a light switch and the light would come on half an hour later if you had to wait for individual electrons to reach the light fitting.
In this case google is your friend.
It still travels. But like I said. back and forth. That is the origin of the buzzing sound when you are near a power line.
so for complex things, computers etc. these are going to generally utilize DC currents.
for larger appliances, in general AC. I can imagine a stove top using AC, a vacuum cleaner, etc.
do PCB's always use DC current? for anything with complex circuitry, are these capable of running on AC? like for example, the buttons on a microwave?
...
>Individual electrons don't 'flow'
I'll take Current for $200, Alex.
He's right, google drift velocity
sure they are almost always moving. but the direction is say X distance, then -X, then X again, for no net movement. at any instance you could say that the electrons have moved from their starting position, but averaged over time, it would be no net movement. correct?
...
The relationship between the macroscopic current and microscopic electron motion is not trivial.
Is your Google is broken or are you going to sit there and compound your ignorance by arguing with someone who actually knows what he is talking About?
If you are in a big city that uses incandescent bulbs you can clearly see the lights flickering out of sync.
It generally depends on the loads required. Ohms law.
If you require low current outputs you work with low voltages because the myriad of circuitry is much smaller and cheaper to manufacture for low voltage environments.
Yes you could build a pc to run at 110v ac but it would be enormous and expensive
I think it means the bulb is worn out usually
Yep. Back and forth is the point. They don't need to leave their original place for long to pass the energy stored. Think of them like pistons.
Fucking captcha. Doesn't it know that as a robot I have problem with it?
Yes, but molecules of water flow, so I take a shit while waiting for the faucet from the water to start flowing.
Water from the faucet* fugg
the intuitive way would be:
>DC: continuous flow of electrons from point A to point B, from which we extract work
>AC: electrons oscillate, and we draw power from that oscillation.
Negative voltages are a-ok, since they are potentials, and any potential is defined up to a constant anyways, so the sign doesn't really tell anything