I am an old EE student, home and university trained, these are the best explanations I've ever seen and my father was pretty good at it, thanks for the refresher. I think it would help your audience if you applied your methods to explain why one would use which motor type where, induction motor speeds, and usable vs rated horsepower. Maybe help explain why a fan motor won't power most tools, etc.
I like how the magnets have an effect on the aluminum. Many bait cast fishing reels are designed with magnets that apply braking force to slow down a spinning aluminum spool when it is cast. The force can be adjusted by moving the magnets closer to or farther away from the spool. Thanks for sharing.
I'm brazilian, and i speak and understand english, but not very well. You explain and talk so well, confident and with a amazing didatics and home made equipments that everbody can understand and lear the principles envolved. Well done! I agree with Tony Watson below, would be nice and useful we learn at school, but not just teory, but the pratice, with a teacher who can explain with the same mastery as you taught.
Just awesome. I could stare at charts and diagrams until my eyes fell out and still not get a complete understanding of these kinds of things, but you make it completely clear in less than 6 minutes.
The way you explain this stuff is perfect for me.... Im an ship/drillinghip electrician and im coming across with so many different kind of motors.... problem is that its difficult to visualise what and when stuff is happening... This is perfect for me... Thanks for this..... many regards and thanks from Erik Thuys from Belgium
Just pulled the motor from an old ceiling fan that runs great, just outdated. It's probably not strong enough to turn into a drill/sander/cutter drive, but you give me lots of ideas! thanks for digging into these concepts!
i was searching months upon months to learn the diffrence between AC and DC motors but someome finally explained it so i can understand. im dutch and i love your projects
Thank you Matthias, I feel like I owe you something now. You made it so simple, and answered the questions I was forming watching it before I could ask them. Thanks again!
Thank you for your videos. I watched your video on the belt sander you build. Thanks to your very thorough explanations I kept watching, one video leading to another, and another, and BAM! I learned something new. THANK YOU.
These motor videos have been fantastically educational and helpful. Thank you for creating and sharing them! I understand so much more about my tools and equipment at work now. Can I suggest a few ideas for future videos along these lines? I would love to better understand the various ways power is transferred from motors to their load. Direct drive, pulleys (including different types of bushings and how they attach to the shafts), gear systems, etc. Advantages and disadvantages of each. Also methods of alignment and adjustment. I'm sure I'm not the only one who would appreciate your intelligent and straightforward explanations on these subjects. Regardless, thanks again!
Matthias, I am glad you occasionally post up videos that have nothing to do with woodworking but instead go in-depth about how common household machines and gadgets work. The educational value of such vids is PRICELESS. Anyway, the video on induction motors I have been showing to railroad enthusiasts to help them understand a little better the traction motors of modern AC traction locomotives and also to help explain why expensive power electronics are needed on modern locomotives to permit active control of the spinning magnetic field's speed and strength. I'm not going to ask you though to do a video about inverters and the like, there are likely plenty of good videos on AC motor field control.
Matthias, I have subscribed. Have been watching a lot of your videos and learnt a lot. Your explanation of your projects and how things work are so clear, entertaining and easy to understand, thank you ,you are a natural teacher. Jez
Now why wasn't I taught this at school, instead of just the theory? Mind, that was 50 years ago! This makes instant sense, rather than just printed words and diagrams. Well done!
Thank you so much for this. I've always wondered how they work but the jargon and pages of details seemed too much trouble to bother with. I enjoy your videos and I guess that's why I could watch an hour long explanation by you. You should have a TV show! :)
These videos are fantastic. You are a wonderful educator. Any videos on using different motor types for actuation - details on sizing, torque, speed selection, compatibility for programming via LabView, Java, Arduino - perhaps applying encoders and building digital control systems (PID feedback)?
Old VCR's (pre-Beta and VHS) sometimes used a DC powered induction motor as a variable brake with a belt drive to sync the spinning video heads to the tape travel. Weird system, as the belt HAS to slip for it to work!!! The pulleys were chosen to spin the heads too fast (5-10%) with no braking. Also worth noting-the small induction motors have very little torque when stopped; they get more powerful as they spin up. Full speed is synced to the AC driving it, so the run speed of these is very stable to a certain load where the motor un-syncs and gets weaker again. Older turntables used them a lot.
Hi, Brilliant presentation. I made a couple of tests of those shaded pole motors on my channel using my Custom Home Made Variac device. But also a couple of Dishwasher/Washing Machine induction motors as well.
I like your explanatory videos. And I wonder if you can explain why a regular drill bit makes a somewhat triangular hole in a sheet of metal (thin, like 0.75 mm) if drilled by a hand drill?
felicitaciones por todos tus proyectos estoy impresionado y ademas porque el trabajo de cámara es excelente y te lo comento porque mi profesión es camarografo pero me fascina la carpintería yo sigo todos tus vídeos pero es primera vez que me atrevo a comentar tu trabajo que es extraordinario un ubrazo y un saludo desde chile
Hi and thanks for your videos. I'm going to echo Tony who is right before me. My degree in physics is 50 years old and it is great to have fresh presentation of what I suppose I learned so many years ago. Great job!!!
Yeah man, thanks for taking the time to post all these videos. They sure give me something to watch that is another world from the... shit that's on TV. Thank You again. Very Cool!
Hey Matthias, I have been wondering lately the reason for most power tools being able to run 120V or 240V. Is there a benefit of using one over the other? It seems like either way they would be using the same amount of power.. Any insight on your thoughts would be much appreciated. Great channel by the way!!
Hey Matthias Great vid, Here i thought i knew something about electricity and magnets , i was wrong, can you explain how a magnet can have an electrical influence on a medal that is non magnetic? such as in the case of your aluminum disk. Thanks
Matthias, any current (!) teacher or college lecturer trying to explain about motors to his/her students could do a lot worse that show these two videos to the class. Outstanding!
I took apart a coffee grinder and it has I believe a universal motor, how would I slow down the spin of the rotor? I tried cutting the wires to reduce the electric flow but I'm not sure that's safe.
PUT A LARGE WATTAGE DRAW IN SERIES WITH THE POWER CORD AND THE VOLTAGE WILL SLOW IT DOWN.........THE HIGHER THE WATTAGE DEMAND........THE FASTER IT WILL GO.........A HIGH RESISTANCE LOW AMP DRAW WILL MAKE IT RUN VER SLOW. BECAUSE OF THE GREATER RESISTANCE. A TOSTER WILL MAKE IT RUN ABOUT RIGHT FOR YOU..........WIRE THE CORDS IN SERIES AND BOTH WILL RUN AT HALF POWER.
What the difference between a 3 phase AC induction motor and a brushless DC motor ? The windings seem identifcal, is the only difference the permanent magnet in rotor instead of the squirrel cage rotor ?
Matthias Wandel AFAIK, this is mostly a matter of the wire gauge and number of turns though, say: low-voltage high-amperage = less turns of heavier wire; high-voltage low-amperage = more turns of thinner wire. where more turns means a stronger field with less amps, but also a higher voltage is needed to drive the field quickly. resistance could also be a factor, but with a lot of 110 and 240 VAC motors, it seems one can reach the rated amperage at around 20 or 30 volts, so I guess conceivably a person could run a 240V 3-phase induction motor using 24v or so, just at a lower operating speed and power?... I have been experimenting with using a car alternator as a 3 phase motor, which has windings which are (for each sub coil) several turns (around 5 or so) of 14AWG wire, and it requires a fair bit of amperage to get it to do much (but, I had it spinning with about 1.5v across the field coil and 0.4 across the phase coils). I am guessing if it were re-wound with a lot more turns of 18 AWG or similar, it could operate considerably better at lower amperage, albeit probably also reducing the maximum power.
GeoDen for controlling the speed, yes. in terms of how the motor is designed though, intended operating voltage and current ranges are fairly critical factors. like, you can't just take a motor designed to run on 440 volts, and swap it out for one designed for 24 volts, it just wont work out well... (say, contactor closes, and stuff explodes...). likewise, a 440 volt motor just wont work well on 24 volts (making it run or getting decent torque will mean running it at an extremely low RPM). for more closely related voltages, say, 440 vs 208, mixing up the motors will tend to either result in poor performance or burn up the motor. in something like a VFD, it may be needed for the voltage to vary with frequency to maintain a given torque (say, voltage goes up with Hz to maintain the rated amperage, and lower at slower speeds to avoid burning the motor). the AWG, number of turns, and also the expected voltage and current ranges, are fairly important for making the motor work or perform well (if these are wrong, performance will either be suboptimal, or in extreme cases, things may fail catastrophically). if you have more turns, then a higher voltage is needed to invert the field quickly, meaning lower maximum RPM at a lower voltage. so, higher-voltage motors tend to have many turns of thin wire, and lower voltage motors tend to have fewer turns of thicker wire. due to reluctance, trying to invert the field more quickly than is possible at the given voltage will tend to cause the current (and torque) to drop significantly. switching the field more slowly will cause reluctance to drop (thus letting more current through). if you have fewer turns, maximum RPM at a given voltage is higher (due to lower reluctance), but torque-per-amp is lower, meaning it will pull more amps at a given speed at a given voltage, and thus the nominal operating voltage at a given speed is lower. or such...
The fact that you were able to explain this complex topic in such a simplistic way demonstrates your deep knowledge of the subject. Thank you for putting together videos like this.
This is really great. I learned about electric motors in 3rd grade (40+ years ago) and thought I knew how they worked, but this is new to me and I don't think I have ever run across these concepts, even in college physics.
i dont know if the average viewer likes these kinds of videos here. But.... i luv em - more please - different topics on how to things work =) informative and short
Pay Way That depends on what area the EE grad wanted to specialize in. Just because you are an EE does not make you have all the knowledge of all things electrical. There are sub classes of the EE field such as: RF, power, analog, digital, communication, electro-mechanical, etc...
EETechs I am sorry but that is ridiculous. These are basic principles for any electrical engineer. If someone has a EE from a university and does not understand these things than they are not really an EE. It would be like a mathematician that cannot calculate an area of a triangle.
I spent four months learning about motors and in 5 minutes you've been more informative than all those classes. Nice and empirical explanations, good work. This is going to be my go to review video.
Thank you for the video. I really enjoy seeing how this stuff works. I hope to develop my understanding of motor types to the point that I am able to distinguish the types of motors I encounter, and anticipate their properties based on that knowledge.
Great video Matthias, learned something new today. Can I ask about your multi-meter/power supply that you used in the video? Do you have a video on its design/construction?
