Flywheel Battery

watching something spin with very little friction can be quite satisfying and this small spinning top can spin for over five minutes with just one spin by hand but if we were to increase the weight of the spinning top it should spin for a lot longer the only problem with increasing the weight of the spinning top is it will also increase the friction at the contact point between the spinning top and the surface below so how about we try and make a magnetically levitated flywheel permanent magnets have two poles which are usually labeled north and south and when a north pole is positioned close to a south pole they are both attracted together but when the magnets are arranged with matching poles near one another the magnets are pushed apart and it's this force that we can use to levitate the flywheel to support the magnets a frame can be built using these aluminium extrusions as they're easily attached together with small brackets almost like a meccano kit i can then mount the magnets to these brackets and bolt them down to the frame for the magnets to levitate an axle the magnets must be arranged with opposing poles like i mentioned earlier but if you've ever tried to levitate a magnet on top of another you'll know it's pretty much impossible to balance that's because if the levitating magnet is offset by the smallest amount not only do the repelling poles want to push it further to the left but these two opposing poles are now pulling each other together and we'll continue to do so until they both collide however if we give the shaft a small bias towards the left we can constrain it with a smooth plate to prevent it traveling any further this essentially turns the axle into a horizontal spinning top where the magnets take the full weight of the flywheel and there is very little friction created on the left as if it were a small lightweight spinning top now this method of levitation was heavily inspired by this small toilet i bought off amazon where there's basically a shaft through the center and two sets of magnets then the whole shaft is constrained by this small glass plate on the side here but if i were to remove this glass plate like so and then try and balance it it just falls straight down depending on which direction i hold it so if i hold it slightly to the left and never hold it slightly to the right so you have to have this little constraining thing which is very little friction but just keeps it levitating nice and simple the flywheel can then be machined out of aluminium for two reasons the first being it's easier to machine than steel on my grandad's lathe and the second and probably most important reason is the aluminium isn't magnetic which could cause some issues with the levitation and even being aluminium it still weighs about 1.4 kilograms which should have plenty of inertia and there we have it a magnetically levitated flywheel now you may notice it's quite wobbly which is due to a number of reasons i initially built this with a threaded shaft as an axle to allow for adjustable positions of the magnets and flywheel but after buying a bunch of these they all seemed to be slightly bent so i then bought some steel shafts which initially seemed to be a lot straighter but long story short i had to heat up the flywheel to fit the shaft through the center hole then ended up bending the shaft by accident and now i can't get the flywheel off of the shaft but i've now balanced it the best i can with some taped on washers and it will happily sit there spinning for about 12 minutes but i have an idea that will make this setup far more interesting what if we could somehow extract the energy from the flywheel to power something because of the magnetic levitation i want to be able to extract energy from the flywheel without making physical contact with it so we need a method of transferring energy through magnetic induction if we hold a magnet near a wire nothing will happen but if we spin the magnet the change in magnetic field will induce a small current in the wire due to faraday's law of induction and this is the basis on how a generator works unfortunately we can't use the spinning magnets from the levitation because their poles run axially along the shaft so the magnetic field doesn't change as they spin so i started building a rotor that'll mount to the same axle as the flywheel and will hold a bunch of magnets which were all orientated with opposing poles facing up this meant that one magnet would have its north pole facing up and the magnet next to it would have its south pole facing up and so on then to generate electricity from this i can wind a lot of wire into a coil and as the magnetic field changes a current is induced in the coil so let's say this magnet induces a current in the upwards direction then the magnet next to it would induce a current in the downwards direction because of their opposite pole orientation this completes the clockwise current direction in the coil and the direction of current flow will alternate as the motor spins creating alternating current or ac therefore we have created an alternator there's just one issue the distance between the magnets and the coil affects the efficiency of the alternator due to the magnetic field being weaker as the distance between the two is increased this isn't a huge issue in conventional alternators as they can run the magnets really close to the coils due to tight tolerance bearings however this magnetically levitated axle isn't exactly precise and could run the risk of the magnets colliding with the coils so to overcome this efficiency loss due to the large safety gap between the magnets and the coil we can add a second rotor of magnets on the other side of the coil this extends the magnetic field to look something like this and greatly increases the strength of the magnetic field in the coils allowing for plenty of space for the shaft to wobble about i then started winding wire around a 3d printed template to create the coil of the alternator but we also need something to turn the alternating current into direct current if we want to power something like a light bulb or an electric motor to convert the ac to dc we need to use some diodes which are essentially one-way valves for electricity current can flow through this direction no problem but isn't able to flow back through the other way and if we arrange four diodes in a formation like this we've built what's known as a full bridge rectifier the way this works is all the diodes are orientated in a way that the current can only flow in the downwards direction so if we connect the alternator coil to these points on the rectifier and apply a current in the clockwise direction the current has no choice but to flow down through this diode and in reverse it has no other choice but to flow down through this diode this means if we connect a dc component like an led to the top and bottom of the rectifier as the coil creates a clockwise current it'll flow from the coil down through this diode over towards the led and then after the led it'll flow towards the top of the rectifier and down through this diode which connects it back to the coil completing the circuit but if the coil creates an anti-clockwise current direction it'll flow through this wire to the rectifier which directs it downwards through this diode along towards the led back up towards the top of the rectifier and finally down through this diode to complete the circuits again so no matter the current direction at the coil the current direction at the led is always in the same direction okay so i've got one of the coils hooked up to the full bridge rectifier and also a capacitor just to smooth out the voltage and also a multimeter to see if we can get some voltage out of this thing so if i mount the flywheel we're getting some voltage i think it's just charging up the capacitor at the moment it's quite a large capacitor let's get it going faster 0.7 of a volt creating electricity from a magnetically levitated flywheel 0.7 of a volt isn't going to power anything interesting so i wound four more coils and connected them in series which should multiply the voltage by four then with some assistance from an electric drill it can generate quite a few more volts but i don't really see much fun in requiring a drill to spin this thing up it would be much cooler to have it as a desk toy that i can spin by hand and have it power something at much lower rpm so to increase the voltage i rewound all the coils with much thinner wire so i could double the number of coils then i soldered together a new full bridge rectifier with slightly smaller diodes and larger capacitors and now i can get nearly 10 volts when spinning it by hand so now the alternator can produce much higher voltage i think we should try and power some stuff so i've got a whole bunch of leds here and if we can get these to glow then maybe we can move on to something with a bit more power such as these electric motors so let's hook up the full bridge rectifier with these crocodile clips then we can connect them to the breadboard and then i'm going to try these red leds because according to this they're the lowest power consumption so they should be the easiest to glow plug it in like that and then give it a spin can you see that on the camera it's probably quite dim that glows a really low rpm on the flywheel let's try plugging in some more there's two leds three leds four they're probably too dim for the camera now so i'll spin it up to speed a bit more five leds eight leds right let's try 10 leds easily powering 10 leds i think i need to close the curtains in this room to see them glowing properly on the camera 10 leds glowing from a magnetically levitated flywheel right so i think what we need to do is uh red lights aren't exactly useful for lighting up a room so let's try some white leds these require a bit more oh wow that works straight away i thought these would require faster rpm because they require higher voltage increase the rpm wow these are really bright let's see how many of these we can do that's four six eight and then finally ten right they're looking quite dim at the moment so let's spin it up powers them with ease well i probably need to balance it if i want to get any higher voltage let's go further so this is 11 13 15 the fly was slowing down so let's speed up again and they all come to life that's so satisfying and 20 leds right so let's spin it up again this is creating quite a decent amount of power i did not expect that to light so many leds so it might actually have a chance of moving some of these electric motors one interesting thing before we move on to the motors you may be able to see in the camera they're flickering slightly and that's because as the alternator spins around um it only creates a pulse of electricity as it passes the coil and they should pulse perfectly in time with the magnets lining up with the coils right so let's unplug these leds and then we'll see if we can power an electric motor how do i position this camera so you can still see the motor and all the wires so i'm not faking it i could be faking all of this it's spinning there's something oddly satisfying about a spinning object spinning a motor i'm just going to take my microphone off so you can hear the motor a bit better [Music] so now if i stop spinning [Music] okay i reckon it's going to struggle with the slightly larger motor let's get this going fast double-handed spin i'm going to rest the setup on top of these mats because i don't think i've made the frame quite square so it wobbles there we go much better nothing i think the only way to get this one to spin is to possibly charge up the capacitors uh beforehand and then plug it in so if we get it spinning charge up the capacitors there we go it's like an electronic gearbox sort of you have to check this out i have the original flywheel alternator setup and if i move backwards a tiny bit we have an augmented reality generated version of it this is done without the need for an android or ios app but instead using a website called thangs who are the sponsor of this video fangs is the fastest growing 3d community with over 3 million available models for you to search store and collaborate on let's say you need to join two of these aluminium extrusions together just a quick search will find you many models to choose from then you can download the one you want and print it out because why waste time designing your own brackets when someone else has already designed one for you or if you have started designing a part and have run out of time to finish it you can use their geometric search to find models that are similar to yours you can also use thanks to create private projects with your friends to share great ideas and collaborate being able to view projects in augmented reality without having to download and import them into your cad software makes it so much easier to know what you're looking at so go check out thangs by clicking my link in the description below and start exploring today big thanks to thanks for sponsoring this video and if you enjoyed this video it'd be great if you could leave a thumbs up down below if you're new to my channel and want to see other projects similar to this then please click subscribe down below and a massive thank you to all of my supporters over on patreon.com for making these projects possible i honestly couldn't do these projects without your support so thanks once again thanks again for watching and i'll see you in the next video goodbye

Channel: Tom Stanton

Views: 3,840,993

Keywords: physics, engineering, flywheel, energy, battery, magnet, magnetic levitation, bearing, friction, alternator, generator, electricity, electronics, energy storage, flywheel energy storage

Id: yhu3s1ut3wM

Length: 14min 49sec (889 seconds)

Published: Wed Jul 21 2021

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