How an Alternator Works
ฝัง
- เผยแพร่เมื่อ 6 ก.ย. 2024
- Find out what's inside a car alternator and just how it works!
The alternator on a car is responsible for taking mechanical energy from the engine and turning it into electrical energy to replenish the battery. It is powered by the crank shaft, through the serpentine belt.
Inside, the pulley rotates a rotor, which is an electromagnet. When powered, the electromagnet spins relative to stationary coils on the housing, called the stator.
Through the right hand rule of physics, we know that as a magnet passes a coil, a current is induced. In this case, there are three separate stator windings, phased 120 degrees apart.
The rotor's electromagnet is often a Salient pole electromagnet, in that each finger alternates pole, from north, to south, to north, etc. When the changing field passes the stator coils, it generates an alternating current.
The three-phase, 120 degree, alternating current produced in the stator coils cannot charge the battery. It is then sent through a rectifier to be converted to direct current, through the use of a bridge rectifier (diodes) and a capacitor as a filter.
Since the engine's RPM varies, so will the alternator's output. However the battery needs a constant 14V to keep charged. The voltage output is controlled through the voltage regulator. It is a solid state device that will sense how charged the battery is, and then send more or less current to the rotor windings. Less current to the electromagnet rotor means less current generated in the stator, and the battery won't get overcharged.
In this video, an alternator is removed and completely disassembled from a 2001 Toyota Corolla.
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hands down one of the best explanations out there of how an alternator works!
+Gabriel Pereira Glad you found it helpful?
Where can I purchase a genuine speedkar99 toothbrush?
+Jim Trainor You have to steal it from my brother for it to be legit.
@@speedkar99 using the toothbrush as a pointer is really original. Keep it going dude
Walmart
I want one too..
Pull out it from any vehicle..
Your style is very different from ChrisFix, Scotty Kilmer, and ErictheCarGuy. I can appreciate all of the styles and I go to different channels when I am looking for different types information. You Sir are at the top of your game and are an educational genius. You channel deserves to be at the top tier.
Does the spider come as standard on all corolla ??
+Yathu prem if the car sits for a while then yes...
+Rhex Arada oh no, I've made a topless corolla, see my convertible video
Yes, the spiders are genetically engineered in Japan and are just as reliable.
Rhex Arada MR2 now classic. The British TV show Wheeler Dealer on Velocity Channel did a restoration on one. I like the last generation of it though, not the old gen.
If they are Toyota spiders, they're really reliable.
You forgot to mention that the specially engineered spider keeps the electric pixies from escaping ⚡️
😂😂😂nice one
man, this was very informative. before this vid I totally misunderstood the purpose of the voltage regulator. Thanks, man!
+RuinMan I'm glad you learned something, thanks
Same here
This is way better explanation than Engineering Explained. I rest my case
+intergratypezero haha thanks ....how so? You prefer to see physical parts?
speedkar99 yes sir. I'm very curious about how the car parts works. With your videos, i get the clearer picture than my imagination.
EE is very bad with electronic stuff
Agreed.
@@two_number_nines but EE is best at ICE stuff -- undoubtedly he explains stuff very easily and with calculations and facts
I feel like the toothbrush is the one talking to me and explaining all this. Thanks Prof Toothbrush!
Fantastic work, my dude. The internet needed some solid, concise, and raw breakdown videos, and your metaphors and explainations are relatable. Also, the toothbrush is hilarious. You are appreciated my man.
Man, I have become the co-ordinator of automotive club in my college. I dedicate this position of mine solely to your channel.
Nobody has the depth of part working as much as I have right now just because of your channel and your way of explaining things.
Thanks man ..😄
Love from India !
Thank you..Well explained, students will excel if you are a lecturer.
+Jithin P V Thanks. I guess I am an automotive teacher
speedkar99 not guess then it's sure
+Jithin P V well I added that to my CV
Sir your explanation is very nicely to understand....👌
ElectricalEngineer: Very impressive.
+siucbset I'm a mechanical engineer
M.E.: With that being said. Shall I assume you will soon be getting rid of that 1999 Solara and getting a 2018 GS350?
+siucbset The solara was sold in April, and I'm happy with my 07 GS350 right now. I recently picked up an 04 camry, not as impressive as the solara though :(
Good combination. GS 350 for summer and Camry for winter. Definitely need a FWD or AWD for winter months in Canada.
+siucbset Yes, though I do use both cars year round, just when it snows I'll use the Camry exclusively. The lexus Michelin Pilot tires are terrible in wet, and its just cheaper to find winter wheels and tires for a Camry.
Love this channel,
Also Chrisfix
& Erick the car guy
They are very informative
...cup of coffee+ cigarrete+ some snack..... +lecture from your video = perfect day.
thank you mister.
You are welcome
I love that this video is not just 'how an alternator works' but 'how every part of an alternator works, right down to the bridge rectifier'
Glad you can learn from my work thanks
liked your diagram and simple explanation and the parts involved. I got to see your face though. loved it.
Thanks I'm glad you enjoyed
Did you memorize all this or is it off the top of your head? Either way is impressive and im obsessed with this channel. Where did you go to school?
+Matt'smobile AutoRepair Thanks
I did some research before hand to get an idea for myself
Then I present
Wow. this is a self taught man.... An inquisitive mind and motivation to understand and share is priceless. thanks
Best explanation on TH-cam! Its a lot better to see actual physical parts explained along with its individual functions rather than a book or a diagram or something. Great work!
Yes , physical parts bring reality to the explanation!
Wow. I now completely understand alternators work. But mostly why there are differences between types of connections. And why I had jump a wire to feedback a signal to the car alternator I installed on my tractor to charge and power lights ect.. this video was very thorough!!
Thanks im glad it helped you learn something new
I seriously doubt that a overcharging alternator will damage your car's computer. The protection circuitry in the unit will sense this and prevent the damage.
6:13 I think you meant 120°. Great video!
Christ on a bike! If I could carry you around in my toolbox to work, that would be just grand!
That was possibly the best explanation of the setup. I've written essays on this, and you hit every point perfectly.
Modern vehicles have such an advantage, having alternators with solid state regulators.
Older types, with the mechanical regulators were a nightmare to jamming up if not kept pristine. Overvoltage scenarios were so common, leading to a stern cooking of the battery. Upgrading from dynamo to alternator certainly provides that constant, and instant punch to whole system on startup. Instead of depending on a dynamo, which relies purely on engine RPM, you've got an instant flow of electron pixies as soon as the internal is excited.
Great video!
Thanks for your insight!
You never mentioned that the spiders are the engineers that live in the system. With out them. You while electrical system will break down
Come to think of it...they sure are
This is a bad ass channel
+Bryce Andrews awesome!
This is an informative video with two items that need to be corrected. First, it is safer to remove the positive cable at the battery first, before removing the cable from the alternator. I know in the car he is showing will not make a difference, since it seems it is a junk yard car. Second, a minor mistake. In 1:28 they are not bolts, but nuts. Overall a good job in showing how the alternator works. Thanks.
Thanks
one of the best video on alternator.... keep uploading buddy.
+vicky singh thank you
I’m here for the how it works teaching toothbrush. Subscribed solely because that toothbrush is just so damn smart!
Thanks for subscribing
I love your videos because you don’t feel you need to add a bunch of time consuming intros and garbage...you just get down to the meat and potatoes and I love it!
Short and to the point is how it's gotta be
Beautiful!!! You should give physics lessons part-time
,
casually.
I've been told alot I should become a teacher
Much better than those 3D videos for me, big thanks!
Same here. I like to see the real thing
Fantastic Video. Cant believe you crunched in so much in less than 9 mins.
Thank you.
Thanks, yep I try to keep things compressed
I am opening a Nissan alternator at present. Figured most of this out already but its good to get confirmation.
Yes they are all very similar
my 8 and 5 year old sons found two funny parts - the spiders and the toothbrush toss at the end. great video!
That was a cool video. I knew the basic principal but not the inner workings. I learned long ago that bump starting a manual doesn't work if the battery is completely drained. There has to be enough charge to get the alternator going.
EXCELLENT!!! the best toothbrush i ever seen, thank you for sharing!
You are welcome
Hot damn this is an awesome video of the mechanical and electronic parts of an alternator. Subbed
Thanks. Check out my other videos for more
Brilliant explanation. No bs. Straight to the point.
Woa! I didn't know that last part about disconnecting the battery while running causing voltage spikes! Makes sense! Thanks.
Yes becareful
This is the best explanation of an alternator I've ever heard. Can you explain how you can bump start a car without a battery in it? Without any input power how can the alternator produce a/c output? Thanks!
That's actually a good question, I would assume you'd need some kind of a battery on it even if it's discharged just to hold charge until the alternator kicks in
I've watched like 10 of these things trying to explain the difference between an alternator and a generator and this is absolutely the best one. Wish I saw this one first so I didn't waste my f*ng time. Good information here. Thanks bro.
Top notch video my dude. Very clear and gets right to the point instead of putting in unncessary flowery language as filler to sound more complex. Have a sub!
I'm glad i came across your video, didn't know that removing a battery from a running engine could get the ecu
Glad you learned something
Your videos always help me understand because you take actual components and break the down vs just talking about them or using whack diagrams
Agreed I think that's what sets me apart
speedkar99 most definitely! Subscribing for sure 👍🏽
Pretty nice, except I wanna say that the ac voltage doesn’t get “mirrored”, the humps below the line get literally cut off and do not transmit through the diodes. It’s the combination of the 3 phases offset from one another that make up that consistent pattern of smaller humps.
A full bridge rectifier works a little differently than a half wave rectifier in this case. Let's compare the different kinds of rectification that are available to us to explain why. In single phase ac, the voltage crosses zero volts every half cycle. You can rectify that with a single diode which will simply block the current flow when the voltage goes negative and pass current when the voltage is positive. This gives you that "cut off hump" for half of your ac cycle you mention. If you use four diodes instead of one, you have a FULL BRIDGE RECTIFIER that can allow the current to pass one direction when the source voltage it is positive, and pass the other direction when the source voltage is negative (from the point of view of the source). In essence, you are turning the wires around every half cycle so that no matter if the ac wave is on the positive side or negative side of the cycle, the current only flows one way through the load. This means that the voltage is always positive from the point of view of the load (since the current flows in only one direction), and you get the back to back positive humps as illustrated in this video. It is worth mentioning that the back to back humps is NOT how three phase rectification works, and sadly, speedkar99 is wrong about that for technical reasons.
Since that is all for single phase, what happens with three phase? Let's go on. Since this alternator is actually three phase AC in Y configuration (we know this because of the common wire), you can rectify the output to DC with 6 diodes (connected as shown in the video). Because the three phases are 120 degrees out of phase, you ALWAYS have full RMS voltage between the three phases. The magnetic fields are rotating in the alternator, and they create a rotating voltage between the phases. I need a diagram to illustrate this. Google for an image of "three phase power graph" with a common wire. You'll surely find one in 1-2 hits. If you don't have a common wire, the zero voltage line is the common. Let's look closely at it and walk through a full cycle (1/3 of an alternator turn I think in this case, by the way).
When Phase 1 is at full positive voltage, the other two phases are at 50% negative voltage. Phase one positive diode conducts full current, and phase 2 and 3 negative diodes each conducts 50% current to the negative phases. Move forward in time until phase 1 falls to 50% positive, and Phase 2 has been quickly rising to 50% positive as phase three falls to 100% negative. Now phase 1 and 2 positive facing diodes are conducting 50% current forward, and phase 3 negative facing diode is conducting 100% to negative. Now go forward until phase 1 is crossing the zero point. At this point phase 2 and three are at about 66% positive and 66% negative (or so). So, phase 1 is neutral and the phase 1 diodes are not conducting at all, phase 2 positive diode is conducting positive and phase 3 is negative diode conducting to negative. Advance until phase 2 is 100% positive. Now phase 1 and 3 are 50% negative, so phase 2 positive diode conducts 100% forward current, and phase 1 and 3 negative diodes each conduct 50% of the current to negative. This keeps going through as phase 3 rises to 100% positive, and phase 1 and 2 are 50% negative.
The story keeps going on and on. Every time a phase crosses the zero, it is doing nothing while the other two pass current between them, and any time all phases have some voltage, there will be current flowing from whichever phase(s) are positive to whichever phase(s) are negative. The diodes make sure the current always flows in one direction through the output by conducting between the positive phases and negative phases in only that one way.
that is why you need 6 diodes. Any time one phase is positive and two are negative, one phase positive diode conducts and two negative phases negative conduct to negative. When two phases are positive, then those two positive diodes conduct to positive, and the diode on the negative phase conducts to negative. There will ALWAYS be at least one phase positive, and at leave one phase negative, so the diodes can always give you power output in the correct polarity.
You can also see that at EVERY point along the waveform, there is going to be about he same amount of power available, conducting by some amount on at least two of the phase at all times. This means that the power you get out of the alternator is going to be a very nice DC power that fluctuates a few percent above and below the perfect voltage. Your battery absorbs current from the system when the voltage fluctuates higher, and your battery generates current when the voltage fluctuates lower, and hundreds (or even thousands) of times per second this occurs to give your car a VERY nice and clean DC power signal to work with. Yes, there is some very high frequency noise in the power, and radios with bad capacitors will generate a noticeable wine when listening to the radio. That's why all electronics on the car have filtering capacitors on their inputs to smooth that out.
But anyway, at no point will you ever have a cut off of output from your alternator so long as the engine is turning at least 500-600 RPM (and assuming there are no electrical faults in the system anywhere).
Great video only addendum is the small capacitor is only for noise suppression and doesn’t do much to smooth the peaks in the output waveform that’s what the battery does.
Also you indicate that the regulator is fed ac to my understanding the ac is rectified immediately after it leaves the stator and the regulator is fed the rectified dc I might have misunderstood that though
The Rotor shaf and pulley should always be spinning together 1:1 right? I'm getting some slippage where the inside is not spinning at times. is the bolt just loose?
Very well done video on the alternator.
Thanks you
One of the best lecture .Thanks. I understood many things in 8 min.
Glad you learned something
Bro ..you are so genius ... How you know all that insider things in Parts ??? ... I couldn't understand easily even i am focusing so hard 😑 .. tell me plz how you able to know all engineering ...
+Zeel Vaghani I do alor of research before I head in and make a video. That way I know what to expect and how to explain it properly.
0:53 you should’ve kept the part where that bolt ran like the wind 😂
Heh
You would make a really good teacher. Good video. Always learning something new here. My girl will thank me for knowing all this later down the road
I'm glad it helped you learn something new
Awesome explanation best put off 5 videos I saw .. great job I replaced my brushes and voltage regulator today .. I had dash lights on usually come on when n alternator craps out but after a bit I noticed it would be fine then work then next day would turn on high review would make it go away made me realize my voltage regulator maybe was bad I replaced both the regulator and the brushes but my brushes were very warm out witch I’m sure that was giving the wrong communication but I still replaced both .. 25 bucks off of eBay .. wish I would have seen this dudes video a week ago .. great job tho . Best vid of this kind on here ..
Why are you not one of the top youtube mechanics?
I'm not a mechanic I'm an engineer
Thanks for Making these videos im studying to become a 3521 for The United states marine corps and this really helped
Glad it helped your class!
Better than physics class....good job
It sure is!
Alternator applies the same load on the engine no matter what?
I mean it consumes the same amount of horse powers if battery is charged and if it's not?
Because i don't see the way how it may reduce the load on an engine.
I love the video. only one little thing speak a little slower more people can catch up with the explanation
Thanks for your feedback. I don't want to bore anyone so I try to keep it quick and short.
You know your stuff, man.
Thanks
Alignment of alternator, Do you need to line up after installing a new alternator? Method or Video review this topic.
Of course it had to align so the belt goes on
@@speedkar99 After review looks like the power steering pully is the only one that could cause a problem if not installed correctly.
@@speedkar99 Go it. Did not know if you needed a straight edge to check or the bolts lock in positon.
So in order for the rotor to make power with the stator the voltage regulator has to supply the rotor with a small amount of power like a pilot flame almost?
Then if the battery is disconnected how would the alternator voltage spike and fry the computer ? Wouldn't it just shut the car off ?
I had to re write my question to make more sense lol
Earned a subscriber, great information man
So it's cause the car would be running there is already power there in the stator and then no more regulator and that's how voltage would spike?
I have to say this was excellent! Thank you! 👍
You are welcome
You are geneious. I will show these to high school kids
Thanks, I hope they'll learn and appreciate this too
Amazing video! Cars are so confusing. What does it mean when your battery light and check engine light comes on at the same time ? Car will not start? Battery is brand new. Overcharge? Alternator needs to be replaced completely?
Excellent explanation, thank you very much.
You are welcome
Scotty didn't explain it like that...WHOA! Thanks!
In the video you stated that the field windings are located 180 degrees apart, when you meant 120 degrees.
+MoutainMan3000 yes i did make a mistake there, and then later I mentioned 120 degrees which is correct.
MountainMan3000 it's not field windings, it's armature windings. In alternator armature winding is in the stationary part and field winding is in the rotating part.
100% well said...it is the best explanation Ive ever heard.. had to listen to it twice.. good job whoever did this..
very nice video full of information. but there is a buzz in the sound, it is not so clear
I know, it's my camera
love the way you explain
always find the required information needed
thanks
That's my style. Thanks
You're videos are great! A lot of how stuff works videos I've seen are either too slow and boring or too fast so I can't keep up with what they're talking about but youre vids are just the right combination of informative without being boring
Great explanation! It's a simple device electric parts wise. Thanks for making this.
You are welcome
Great description, thank you
You are welcome
It's videos like this that should make every guy who likes cars subscribe!
+wholeNwon Thanks, subscribers are welcome!
One question. When the car is running it`s the alternator that powers everything in the car right? The battery is not doing that unless the car stops if I understand this correctly?
Yes alternator provides power to the car.
So those triangular claws surrounding, are the magnets or just metal; and they become north & south magnets when electricity is sent to field windings it surrounds?
I bet those spiders went for a ride when he spun it haha.
Sure did
What's about the current the alternator produce from rotation? If the alternator produce 100 amp current at 1000-1200 rpm and if the battery capacity is 50 amph then the battery will be charged within a short time and it will be over loaded by current. Please explain the battery current capacity and the alternator current that it produces. Thanks in advance.
The regulator stops the alternator from over charging the battery
Best explained and concise vid. I've seen on TH-cam. Thanks.
You are welcome. Best on TH-cam yay!
So if you want to bench test an alternator you have to connect a battery to it, or some other voltage source to provide a dc voltage to the rotor in order to make that an electromagnet and get 14V out of it. Right?
Love the toothbrush pointing
It makes an excellent teach-brush
Does it charge in e car battery????when we drive e-car or e-bike
what is your question?
the best video on alternator
I really appreciate this channel. The way he explains how things works is perfect for me and many others . Thumbs up if you appreciate speedkar making the world a slightly better place.
Why are you so knowledgeable? Why? Why?
I learn as I go
Hi Speedkar! I miss all ur how-to fix videos. Do u still have the Lexus GS? Have u had any issues with it? I’m considering getting one also.
+Nathaniel D. Thanks
I would like to go back to how to videos soon.
Yes I have my GS and I love it. No issues with it, just the typical Lexus transmission lag in traffic. Mine has 241,000km
GM 140 amp alternator, battery post nut will not remove any recommendations? tried penetrating oil, removal from car put it on Vice to get a better grip. Plastic piece around battery post turning also. Do you think alternator is permanently damaged?
You might be in for a rebuild
@@speedkar99 Thanks, Amazon new alternators seem reasonably priced for this GM category.
Move from here 😂😂
+TheMidnightNarwhal Stupid spyder
You can't go wrong with this guy.
I have a question, for my 01 Camry,4 cylinders,regarding the three wires at the back of the alternator. Out of the three wires,one should have a battery voltage,right? Or all three should have battery voltage ? Because,mine,all three wires have battery voltage. And the charging system doesn’t run right...can you explain? Thank you. Really need some good informations on this problem
The 12V power line is the one that's bolted on
Perfect explanation!!!!
Thanks
MAN YOU ARE ABSOLUTELY AMAZING PERSON.👍🏼👍🏼 this video and rest all of the videos which you make are so easy and simple to understand. Thanks alot, for clearing A TONNES of doubts which were running inside my head from so many days.
So what part of an alternator most likely to cause a failure given the author's descriptions of the parts?
As always outstanding presentation and explanation. Compact and comprehensive. Also appreciate the extra work of printing out these diagrams for detailed explanation.
This man's reaction to the spiders 😂😂🤣
Haha funny eh
@@speedkar99 I was like: Why is he including that in the video? Then I started laughing my brains out because what??? 😂😂😂 Very funny 😭
#FULLBRIDGERECTIFIER
electroboom
And some shit blows up.
At 8:28 not true. On modern vehicles, you should never disconnect your battery while your vechicle is running. You can damage a lot of electrical components if you do, but if you did disconnect the battery, the voltage regulator would still get power from the rectifier bridge through the exciter diodes (diode trio).
Agreed here. The voltage regulator nis driven by the battery.
Base on the schematic in 7:10, can we replace 6 diodes by 8 diodes? If yes, is it more durable than the rectifier with 6 diodes? Thank you.
+Utuber Yes but then you'd need an additional phase and coil windings for those diodes.
Very well explained ! God bless you.
What runs the gas pump and spark plug coils when the car is running?
Battery