You have really inspired me. I have always been a tinkerer but shied away from electronics the more digital it became, but I will try to tackle some of those projects I have been intimated by. Thank you for simplifying it for me.
don't mistake solid state components for digital chips, almost anything done with chips now, can still be done with modern solid state components, just much more complex. a chip is just a bunch of logic controlled switchs, various thyristors can be used to achieve the same effect, and you just build the logic with the circuit. the chips just make the pcb's way smaller, thats why they are used.
Excellent demonstration using logic switching. I would like to see higher speeds. First thought is a really nice gyro with more mass. And I also wonder if you can't somehow watch the slight variance on the coil itself as the attracting magnet passes by ... hopefully closing the timing gap to a more discrete level. And of couse a final way would be to increase the spokes to 4 or 5. I'm sure there's a threshold at some point where too many spokes would be detrimental to the desired outcome. Thanks again sir.
Kid: hey show me how to make a paper airplane. This guy: sure! ~*three hours later*~ This guy: ok we are going to need some plexiglass for the Windows, and did you ever get a helmet? Kid: yes and I found my passport!
as a side note, you can't take the motor out of a computer fan. the fan blade is actually an integral piece to the motor. the plastic hub that holds the blades is also holding the permanent magnet, so you can't remove it without destroying the motor.
If you use a p-type FET up near VDD instead of n-type near GND, you can get rid of the inverting transistor and its accompanying resistors. Awesome project idea, BTW. I made it with my kids and it was a lot of fun.
Challenge mode is to do an induction only version. Replace the magnets on the spinner with coils and add yet another coil to power the coils on the spinner that counteracts the stator coil. Playing with angles and such would likely be more fun. (My guess is a hub-centric coil powering all the arms might be the easiest, almost like having a brushed rotor but eliminates some alignment or undesired thrust issues.)
Now, if you tuned the speed of the fidget spinner to correspond to a musical note, wired up a bunch of fidget spinner magnets, and had guitar pickups next to each fidget spinner do you think it would be an interesting way to create music? essentially like an old school tonewheel organ.
Really nice pair of videos! Something I've been thinking about ever since I saw a fidget spinner :) I was thinking you don't need to invert the signal, you could just put the sensor 180 degrees away and it would fire at the right time ( or 180/3 for the 3 arms )
Leo - you need to invert the signal to turn the coil ON when the magnet crosses the Hall sensor - normally it would turn the coil OFF - your suggestion might work but it would draw much more power as the coil would be on most of the time and only go off when the magnet goes by. Hope that makes sense! dave
Very cool! Going to have to build one for my students. Maybe with some kind of track around the perimeter to adjust the timing and find other points that work.
Nice demonstration for those with some knowledge of electronics. I ahve a 2008 model eZip Trailz, 24v, 450 watt electric bike. I've been watching what videos I can find that's educational about the hall sensor and brushless hub motors. Thanks a grand for the video.
I hope I never have to convert my eZip Trailz over to the rear hub motor because they require much more voltage to do the same work as my brush reduction motor for the same torque and speed for the weight I carry. My motor is getting to be expensive to replace because some hobbyist that's into building remote controlled tanks are using them.in their projects because of the torque and speed in a small form factor.
Thank you so much for this video. I just recently made one of these motors out of an old VCR drum with just a Hall effect sensor and a mosfet no npn transistor. I was getting so frustrated because the coil only ever turn on when the hall sensor wasn't activated. I thought the hall sensor outputs high when activated. I don't have the greatest knowledge in transistors so I just gave up for the time being. I'm defiantly gonna try this schematic now. Thanks again!
Dave Bodnar your schematic works circuit works flawlessly. I have 6 magnets on my rotor and 4 coils on my stator all connected in parallel. Using your RPM meter trick I was easily able to get it to 500 Hertz. Doing the math that works out to 5,000 RPM. This was at 17 volts running at around 0.4 Amps. My power supply goes up to 32 volts at 10 amps but I was scared to turn up the voltage any higher in fear that my glued magnets would fly off! This motor is extremely efficient. It should be noted that I had to switch out the power transistor for a much bigger one. I am currently using an IRFP260N MOSFET. I could Email you some pictures if you'd like.
Dave Bodnar sure thing! I'm a little busy right now but I'll try and post a video of it running within the next couple days or so. I'll give you a heads up when it's uploaded
@@parleyk4503 You can use all kinds of ways to make it work. You can also use pnp transistor along with your npn mosfet and it will do the same thing. However I don't think your spinner will go any faster or better thant when you had just used the NPN. With just the NPN, the only difference is it most likely uses more Amperage since on time is longer than off time on the mosfet and therefore the time frame that the coil is on. Actually it may even spin faster.
How about feeding the coil directly with pulses generated in an oscillator circuit. Than you control the speed like in a synchronous AC clock motor. Or mabe feeding it from a 60 Hz low voltage transformer like the variable voltage transformers in old train sets? Then you could show that speed is independent of voltage when you reach a certain supply voltage.
I do know that large manufactured single phase motors will run if you give them a push in the direction you want them to rotate in if the second starting winding isn't connected or working. The starting winding is offset from the running winding and wound with iron wire or has an AC capacitor in series. You reverse the connections relative to the starting winding to reverse direction. That gives the motor a rotating magnetic field. So maybe you need more coils? An induction motor works with just steel and aluminum coils in the rotor but it has a slip speed which is less that what you would expect as the synchronous speed.
The aluminum coils aren't wire but sort of meant to be turns like in a very low voltage transformer so they get a current induced in them by the stator so they get the induction motor name.
This is amazing, thank you so much for posting this. I was wondering if you spun the fidget spinner by hand could you use this essentially as a generator and detect voltage through the wire connections? I'm still new to electronics so I apologize is this is a silly question.
Sara - Any time a magnetic field interacts with a coil of wire electricity can be generated- that said, you probably could use this as a generator but it surely is not optimized for that purpose. thanks for letting me know you enjoyed the project dave
So, what you are saying is it is possible to make a dynamo that not only is self powering, but generate energy as well? I know some science, but not engineering... Love the video anyway.
Hi, I was wondering what is the difference between this hall effect sensor ( SS443A) and the A3114? Do they do the exact same thing? Thanks in advance for your answer.
@@DaveBodnar Thanks so much. I should have asked a couple more questions. I have IRFZ44N if that would replace the IRL520 Mosfet. And I heard you saying that the hall sensor pulls low when the magnet passes by it and so you incorporated the NPN 2n2222. I am wondering when you say pulling low does that mean that the hall sensor actually turns off instead of turning on and the NPN transistor reverses it, so when the magnet passes the hall, it will turn on the coil instead of being on the rest of the time and off when the magnet passes by it?
@@alchemy1 Not sure about your Mosfet - the IRL520 turns on with a 5 volt input where most Mosfets require higher voltage - yours might work but it may not. When the sensor goes low it shows ground on the output pin rather than VCC dave
@@DaveBodnar Awhile back I made this set up in the link below, schematic at 1:27 into the video. I noticed the LED was on when the magnet was not by the hall sensor and when it got close to the sensor the LED will go off. To me, it basically meant that the coil has current running through it when the magnet is not by the hall and when it gets close to the hall, the current stops. To me, it looks backward. Shouldn't the coil be energized when the magnets get close to the sensor just like the reed switch? The coil being energized when it is not supposed to and when it needs to it is turned off. So I had to play around to place the hall just at the right place to get maximum efficiency. So when you say the hall goes low ( it means the output is grounded implying no output, no positive current) which is the same as being off I guess, the same as the LED going off, no current through the coil? If I have said it that right and my observation was accurate, I am assuming that your setup is much more efficient than this setup and the coil is energized, at the right time when the magnets pass by the sensor and not in between. I was never got much speed with the setup and I like to try your setup now. I will get the IRL520 MOSFET. I am trying to get some speed and get things to work in a meaningful way. After this, I will do the optical sensor. I think I will be pleased to see the wireless interaction. It is all so fascinating. Here is the link at the point of the diagram that I did before I watched yours. I was not happy with the result. ruclips.net/video/WjEJ7FFgbuI/видео.html Thanks for everything you do Dave.
@@alchemy1 That is a very nice video & implementation of a demo motor - I can't tell from the video if the LED properly follows the magnet hitting the sensor - I do know that mine does turn on when near a magnet - give it a try! dave
thanks for posting. here are some very late thoughts. in general, an electric motor is most efficiently used when it operates, continuously, at its natural or designed optimal rotation rate. this cannot occur in any practical sense, where a motor is running, Un-loaded. the absence of an output shaft makes (correct) loading of such a motor difficult. on the other hand, an impeller/fan to the rotor might be effective. motor speed under load can be observed; and varied by varying impeller drag. cheers
Dave's presentation is great! Bill Nye could learn a lot from Dave. Now, if Dave could connect with the guy that put a pull starter on a Wankel model airplane engine (and is not sure what to do with the 2 HP), and help him to get the Wankel running on nitro to run on LPG, then my life's meaning is clear. As mud. Actually it was the fan on the Wankel vibrating and the comment below about a PC fan that got me thinking. And now I look at more Star Trek classic videos. Thanks
When the magnets pass the coil you should get a slight back emf. would it be possible to detect this with an op amp say and make one with no sensor at all ?
Any of the non-contact sensors work very well - Hall sensor or optical. I used optical (with a laser) in the latest video - see: ruclips.net/video/NYf8HwF1G5Q/видео.html dave
In your circuit diagram that you show at ~0:55 seconds, You have R3 and R4 in parallel yielding 500 ohms. Any reason you choose to draw this schematic this way. Other options were to actually use a 500 ohm resistor or to draw the circuit with the resistors in close proximity to visually show the parallel'ness (is that even a word :-) )
Paul - interesting observation! I am not sure that it would work with the resistors replaced with one 500 ohm or not - I need to experiment a bit and see what happens...... FYI, I drew it that way to show that the gate on Q2 needs to be pulled up as does the collector on Q1 thanks! dave
@@DaveBodnar That is where I saw your diagram on the webpage. That was a question. I don't know what I am right about. That is where the problem is, not clarity. The webpage doesn't say anymore than what you are showing here. In your video it appears that you are explaining ( sort of explaining) that the reason you are using a transistor is that when the hall is low ( meaning the magnet is by it) you want the coil energized and not the other way around. Evidently the hall sensor instead of showing output ( as the teaching goes) by the presence of the magnet, it is actually losing whatever output it had to begin with and furthermore it is not much of an output at all because it needs pull up resistor so that the FET gets real voltage that it needs. So please give the explanation that is actually needed. How on earth does your NPN transistor or your N channel FET make this possible as both are turning on with pull up resistors and therefore actually turning off when magnets pass the hall. I am not an educated man. Hello, please don't let me hanging. Thank you.
@@DaveBodnar So what you are not saying is that when the magnet is not by the hall the transistor is on. This causes the current form R4 along with R3 to go through the NPN to the ground, thus the FET is off. And when the magnet is by the hall, NPN is off so at the point voltage is available for the FET and since both R3 and R4 is same value, the same voltage exist across them and that voltage turns on the FET. With respect to the Hall, when the magnet is not by it, the current flows through R2 and R1 into the NPN base and when the Magnet is by the hall, the current goes into the hall sensor itself through its signal wire. In other words, it's signal wire is actually a path to the ground inside the hall and not like some output positive voltage. Are those what is happening?
i think it must not neccessarily be magnets beeing glued on the spinner. but any item that can receive induction currents might work. maybe even the bearing in the spinner's arms could do it. the forces would not be that strong but for keeping a spinner turning stronger than its friction it could be sufficient. multiple coils could work for making it a more constant force. doing longer current phases could also work for giving more permanent power. as the spinner's speed is typically changing not only the turn on point should be nice to select but as well the turn off point. so a second sensor and an R-S-flip-flop could do much of the desired works. (Other folks would even go for a micro controller. just point out where the "uphill" road for the more complex design could be.)
If one added a magnetic current generator to the spinning piece, could it generate enough electricity to just give the impulse for the motor to keeping spinning? I guess it shouldn't work, otherwise you had a self sustaining motor, in other words perpetual motion.
There is a connection to 5 volts that powers the breadboard - if you look closely at about 1:10 into the video you will see a red/black pair of wires going off of the back of the board. dave
Awesome now if you had a coil below everything you could theoretically produces more voltage than it wpuld take to run it. Passing through a transormer you could essentially allmost make a self sustaining generator......??? Can you send me one of these setups? Lol
David - I never pushed it beyond what is shown in the video - inexpensive toys with questionable quality control tend to self-destruct when pushed too far! dave
I built my own version of this, but slightly *BEEFED UP* you dont need to invert the signal from the hall sensor, i just connected mine straight to a mosfet for the coil and it works great. I used 16awg magnet wire for my coil and ran it off a 2s lipo and used a giant heat sink on the mosfet. Once i had finished it, i was super excited to try it out 1:56 I forgot to glue the magnets on One flew off and almost dented the wall GLUE YOUR MAGNETS Enought said
@@DaveBodnar *UPDATE* Super glue is NOT ENOUGH to hold the magnets on. I used a combination of gel glue and then normal super glue to fill in any cracks. After hooking my masterpiece up to a 2s lipo, it sounded like an f1 flooring it, as the spinner revved up. Until the point where super glue was not enough to hold the magnets on. One of them flew off (luckily it missed me) My advice if anyone else wants to make a beefed up version of this, build some kind of guard around it and stand very far away
I fully agree - I have been doing some additional experiments and have been using magnets that have a hole in the center so that I can use a bolt to hold them on. Glue is not enough! Stay tuned for a new video showing some new ideas. dave
@@DaveBodnar update #2 I successfully secured the magnets with more superglue (enough to hold them on) and put an acrylic guard around the apparatus. The magnets haven't flown off, but i have encountered a new problem. I have reached the maximum speed of the bearing. Once it gets to a certain speed the bearing will vibrate, and make a ReEEeeeEeeeE sound and slow down. Im going to try and get some ceramic bearing to see if that helps. I know my motor is capable of more speed so im going to try to get to the point where the spinner itself cant stay together. (With safety equipment)
I have seen the vibrations as well. The bearings are inexpensive and prone to such problems. You could try a different brand spinner or even a bit of light weight lubrication or graphite to smooth things down. Have you measured the speed of rotation? My best speed so far is a bit over 5000 rpm - not bad and a bit scary when it spins at that rate! dave
I caught another video where a fellow was using a laser pointer to illuminate some clear marbles for an interesting light effect. (That vid is here: ruclips.net/video/ZvislxtabcI/видео.html) I was curious if you had ever thought of integrating something such as that for your brushless fidget spinner project.
Well clearly if anyone can, you certainly could. Thanks for the wonderful vids. Very enlightening and resourceful. I bet your students appreciated you. Take it easy Dave. Subbed.
Thank you for the quick response, Mr Bodnar. It is impossible to generate more energy in a system than what it consumes. If this were true then the device would be running in overunity mode and would be over 100% efficient which is impossible. However it is completely possible to generate more energy than what the device consumes if the local enviroment is involved or some other energy that is outside of the system which can be drawn or attracted into the system. Namely the power of magnets. Any wisdom to talk about that for young inventors like me? I'm working in this for very long time You have great inventions!
F P there are plenty of examples of systems using external energy. Look at wind turbines or hydrogeneration. There is no magic way to just suck energy from the air.
F P If you add a coil top and bottom of each of the other 2 arms you can collect the voltage spike generated off each of those 4 coils as it passes the magnets into a capacitor bank or rechargeable battery. You can also capture the back EMF voltage as the field collapses off all 5 coils if you want more output, and more output again is gained by adding more arms and coils. Some food for thought for you.
Doing so would create drag in the form of a opposing magnetic flux, therefore requiring more current from the power supply, there is no free energy to be taken from this or any system.
You need to try a pulse circuit. Read www.nutsvolts.com/index.php?/magazine/article/august2012_Williams on a solar powered pendulum. It will pulse the coil so as to repel the magnetic each time it passes under the coil. No need for a timing circuit like your light or hall effect stuff.
Need more teachers like this guy. I really like the way he explained what he was doing.
Very well spoken, I've been into electronics for 40 years. Thanks,
Thank you for putting this together with a link. It is very interesting
Woah I wish you were my science teacher in school
You have really inspired me. I have always been a tinkerer but shied away from electronics the more digital it became, but I will try to tackle some of those projects I have been intimated by. Thank you for simplifying it for me.
I appreciate your taking the time to let me know that you are going to give some projects a try - please let me know how it goes - enjoy!
dave
don't mistake solid state components for digital chips, almost anything done with chips now, can still be done with modern solid state components, just much more complex.
a chip is just a bunch of logic controlled switchs, various thyristors can be used to achieve the same effect, and you just build the logic with the circuit.
the chips just make the pcb's way smaller, thats why they are used.
Excellent demonstration using logic switching. I would like to see higher speeds. First thought is a really nice gyro with more mass. And I also wonder if you can't somehow watch the slight variance on the coil itself as the attracting magnet passes by ... hopefully closing the timing gap to a more discrete level. And of couse a final way would be to increase the spokes to 4 or 5. I'm sure there's a threshold at some point where too many spokes would be detrimental to the desired outcome. Thanks again sir.
All good ideas - just what I was hoping for - you and others taking this as a starting point and improving & innovating!
thanks
dave
One of the best videos iv seen in a long time.
Josh - I appreciate the feedback - thanks!
dave
Do you think is it possible to design out of this prototype a brushless dynamo for the bicycle that is more efficient than a normal hub dynamo?
Kid: hey show me how to make a paper airplane.
This guy: sure!
~*three hours later*~
This guy: ok we are going to need some plexiglass for the Windows, and did you ever get a helmet?
Kid: yes and I found my passport!
This is how computer fan motors work I think. I took one open once and there was a little circuit board in there with a hall-effect sensor. Neat!
David - it is good to hear that you liked the project - thanks for your comment!
dave
as a side note, you can't take the motor out of a computer fan. the fan blade is actually an integral piece to the motor. the plastic hub that holds the blades is also holding the permanent magnet, so you can't remove it without destroying the motor.
Is there a way to harvest the hall sensors from the fans. Those things are ridiculously expensive at my local stores, $8!!!!
You have created a fine little "Electro-Figital Spinner" ;) .
If you use a p-type FET up near VDD instead of n-type near GND, you can get rid of the inverting transistor and its accompanying resistors. Awesome project idea, BTW. I made it with my kids and it was a lot of fun.
Good suggestion, John-Paul.
Thanks
Dave
Challenge mode is to do an induction only version. Replace the magnets on the spinner with coils and add yet another coil to power the coils on the spinner that counteracts the stator coil. Playing with angles and such would likely be more fun. (My guess is a hub-centric coil powering all the arms might be the easiest, almost like having a brushed rotor but eliminates some alignment or undesired thrust issues.)
Now, if you tuned the speed of the fidget spinner to correspond to a musical note, wired up a bunch of fidget spinner magnets, and had guitar pickups next to each fidget spinner do you think it would be an interesting way to create music? essentially like an old school tonewheel organ.
Really nice pair of videos! Something I've been thinking about ever since I saw a fidget spinner :) I was thinking you don't need to invert the signal, you could just put the sensor 180 degrees away and it would fire at the right time ( or 180/3 for the 3 arms )
Leo - you need to invert the signal to turn the coil ON when the magnet crosses the Hall sensor - normally it would turn the coil OFF - your suggestion might work but it would draw much more power as the coil would be on most of the time and only go off when the magnet goes by.
Hope that makes sense!
dave
Very cool! Going to have to build one for my students. Maybe with some kind of track around the perimeter to adjust the timing and find other points that work.
Go for it, Evan - let me know how they like it
dave
Dave Bodnar We will see. I'm also wondering how three coils would work. I might try and run it from a brushless ESC just for fun.
Pretty nifty designs! The hall effect sensor would have been my first choice.
Really nice demo! Thanks
Nice demonstration for those with some knowledge of electronics.
I ahve a 2008 model eZip Trailz, 24v, 450 watt electric bike.
I've been watching what videos I can find that's educational about the hall sensor and brushless hub motors.
Thanks a grand for the video.
Thanks for letting me know that it was of value to you !
dave
I hope I never have to convert my eZip Trailz over to the rear hub motor because they require much more voltage to do the same work as my brush reduction motor for the same torque and speed for the weight I carry.
My motor is getting to be expensive to replace because some hobbyist that's into building remote controlled tanks are using them.in their projects because of the torque and speed in a small form factor.
This is really good. Thanks for producing these videos. ;learning heaps
It is my pleasure, Werner
dave
Thank you so much for this video. I just recently made one of these motors out of an old VCR drum with just a Hall effect sensor and a mosfet no npn transistor. I was getting so frustrated because the coil only ever turn on when the hall sensor wasn't activated. I thought the hall sensor outputs high when activated. I don't have the greatest knowledge in transistors so I just gave up for the time being. I'm defiantly gonna try this schematic now. Thanks again!
Be sure to let me know how your unit works.
thanks
dave
Dave Bodnar your schematic works circuit works flawlessly. I have 6 magnets on my rotor and 4 coils on my stator all connected in parallel. Using your RPM meter trick I was easily able to get it to 500 Hertz. Doing the math that works out to 5,000 RPM. This was at 17 volts running at around 0.4 Amps. My power supply goes up to 32 volts at 10 amps but I was scared to turn up the voltage any higher in fear that my glued magnets would fly off! This motor is extremely efficient. It should be noted that I had to switch out the power transistor for a much bigger one. I am currently using an IRFP260N MOSFET. I could Email you some pictures if you'd like.
That sounds super! Quite an accomplishment! Please do send some photos or do a video on RUclips.
email is dave@davebodnar.com
thanks
dave
Dave Bodnar sure thing! I'm a little busy right now but I'll try and post a video of it running within the next couple days or so. I'll give you a heads up when it's uploaded
@@parleyk4503 You can use all kinds of ways to make it work. You can also use pnp transistor along with your npn mosfet and it will do the same thing.
However I don't think your spinner will go any faster or better thant when you had just used the NPN. With just the NPN, the only difference is it most likely uses more Amperage since on time is longer than off time on the mosfet and therefore the time frame that the coil is on. Actually it may even spin faster.
How about feeding the coil directly with pulses generated in an oscillator circuit. Than you control the speed like in a synchronous AC clock motor. Or mabe feeding it from a 60 Hz low voltage transformer like the variable voltage transformers in old train sets? Then you could show that speed is independent of voltage when you reach a certain supply voltage.
Kim - I did some experiments along the lines that you describe without much success - give it a try and let us know how it goes.
dave
I do know that large manufactured single phase motors will run if you give them a push in the direction you want them to rotate in if the second starting winding isn't connected or working. The starting winding is offset from the running winding and wound with iron wire or has an AC capacitor in series. You reverse the connections relative to the starting winding to reverse direction. That gives the motor a rotating magnetic field. So maybe you need more coils? An induction motor works with just steel and aluminum coils in the rotor but it has a slip speed which is less that what you would expect as the synchronous speed.
The aluminum coils aren't wire but sort of meant to be turns like in a very low voltage transformer so they get a current induced in them by the stator so they get the induction motor name.
cool demonstration, thanks!
fun to watch. can you now make the motor power something? anything, i just want to see it do work!
This is amazing, thank you so much for posting this. I was wondering if you spun the fidget spinner by hand could you use this essentially as a generator and detect voltage through the wire connections? I'm still new to electronics so I apologize is this is a silly question.
Sara - Any time a magnetic field interacts with a coil of wire electricity can be generated- that said, you probably could use this as a generator but it surely is not optimized for that purpose.
thanks for letting me know you enjoyed the project
dave
So, what you are saying is it is possible to make a dynamo that not only is self powering, but generate energy as well? I know some science, but not engineering... Love the video anyway.
Wonder what RPM a fidget spinner will fail at.
Hi,
I was wondering what is the difference between this hall effect sensor ( SS443A) and the A3114? Do they do the exact same thing?
Thanks in advance for your answer.
I believe that either will work for this project. Functionally they appear to be very similar.
dave
@@DaveBodnar Thanks so much. I should have asked a couple more questions. I have IRFZ44N if that would replace the IRL520 Mosfet. And I heard you saying that the hall sensor pulls low when the magnet passes by it and so you incorporated the NPN 2n2222.
I am wondering when you say pulling low does that mean that the hall sensor actually turns off instead of turning on and the NPN transistor reverses it, so when the magnet passes the hall, it will turn on the coil instead of being on the rest of the time and off when the magnet passes by it?
@@alchemy1 Not sure about your Mosfet - the IRL520 turns on with a 5 volt input where most Mosfets require higher voltage - yours might work but it may not.
When the sensor goes low it shows ground on the output pin rather than VCC
dave
@@DaveBodnar Awhile back I made this set up in the link below, schematic at 1:27 into the video. I noticed the LED was on when the magnet was not by the hall sensor and when it got close to the sensor the LED will go off. To me, it basically meant that the coil has current running through it when the magnet is not by the hall and when it gets close to the hall, the current stops. To me, it looks backward. Shouldn't the coil be energized when the magnets get close to the sensor just like the reed switch? The coil being energized when it is not supposed to and when it needs to it is turned off. So I had to play around to place the hall just at the right place to get maximum efficiency.
So when you say the hall goes low ( it means the output is grounded implying no output, no positive current) which is the same as being off I guess, the same as the LED going off, no current through the coil?
If I have said it that right and my observation was accurate, I am assuming that your setup is much more efficient than this setup and the coil is energized, at the right time when the magnets pass by the sensor and not in between. I was never got much speed with the setup and I like to try your setup now. I will get the IRL520 MOSFET. I am trying to get some speed and get things to work in a meaningful way. After this, I will do the optical sensor. I think I will be pleased to see the wireless interaction. It is all so fascinating.
Here is the link at the point of the diagram that I did before I watched yours.
I was not happy with the result.
ruclips.net/video/WjEJ7FFgbuI/видео.html
Thanks for everything you do Dave.
@@alchemy1 That is a very nice video & implementation of a demo motor - I can't tell from the video if the LED properly follows the magnet hitting the sensor - I do know that mine does turn on when near a magnet - give it a try!
dave
Hi sir,
can we use hall sensor or optical sensor in place of carbon brushes in DC motor ?
as BLDC motor please reply sir.
You certainly can - that is what is currently done with brushless motors
dave
thanks for posting. here are some very late thoughts. in general, an electric motor is most efficiently used when it operates, continuously, at its natural or designed optimal rotation rate. this cannot occur in any practical sense, where a motor is running, Un-loaded. the absence of an output shaft makes (correct) loading of such a motor difficult. on the other hand, an impeller/fan to the rotor might be effective. motor speed under load can be observed; and varied by varying impeller drag. cheers
hello @dave, love the videos! Couldn't you try with a solar power source?
You certainly could use solar power - it would take a fairly large solar panel as the power consumption is high but it would work.
dave
Dave's presentation is great! Bill Nye could learn a lot from Dave. Now, if Dave could connect with the guy that put a pull starter on a Wankel model airplane engine (and is not sure what to do with the 2 HP), and help him to get the Wankel running on nitro to run on LPG, then my life's meaning is clear. As mud. Actually it was the fan on the Wankel vibrating and the comment below about a PC fan that got me thinking. And now I look at more Star Trek classic videos. Thanks
Awesome video!
When the magnets pass the coil you should get a slight back emf. would it be possible to detect this with an op amp say and make one with no sensor at all ?
It certainly should be a detectable event every time the magnet passes - give it a try and let us know if you get it working
dave
there are a few diamagnetics you can use as mono poles
what sensor did you find to be the most effective?
Any of the non-contact sensors work very well - Hall sensor or optical. I used optical (with a laser) in the latest video - see:
ruclips.net/video/NYf8HwF1G5Q/видео.html
dave
WOW, Somebody actually did something useful with a fidget spinner.......... :-)
why not use a micro controller directly? then you can program it to create an type of signal as you like or a 555 timer?
I have experimented with an Arduino but have never been satisfied with the results compared with the simpler Hall and light sensor options
dave
In your circuit diagram that you show at ~0:55 seconds, You have R3 and R4 in parallel yielding 500 ohms. Any reason you choose to draw this schematic this way. Other options were to actually use a 500 ohm resistor or to draw the circuit with the resistors in close proximity to visually show the parallel'ness (is that even a word :-) )
Paul - interesting observation! I am not sure that it would work with the resistors replaced with one 500 ohm or not - I need to experiment a bit and see what happens......
FYI, I drew it that way to show that the gate on Q2 needs to be pulled up as does the collector on Q1
thanks!
dave
>"..I need to experiment a bit and see what happens......"
I'd be interested in hearing what your findings are.
Paul.
Another option maybe, as there is not a lot of current needed at the gate of the MOSFET, is to ditch one of the resistors altogether.
This is more interesting that my actual science class
The photo resistor gets used in arduino stuff now and again, for instance, if making a home-made punch card reader or the like.
In the circuit diagram, is the transistor NPN and the Mosfet N channel?
You are correct - the information on the web page may make that clearer.
see: trainelectronics.com/FidgetSpinner/
dave
@@DaveBodnar That is where I saw your diagram on the webpage. That was a question. I don't know what I am right about.
That is where the problem is, not clarity. The webpage doesn't say anymore than what you are showing here.
In your video it appears that you are explaining ( sort of explaining) that the reason you are using a transistor is that when the hall is low ( meaning the magnet is by it) you want the coil energized and not the other way around. Evidently the hall sensor instead of showing output ( as the teaching goes) by the presence of the magnet, it is actually losing whatever output it had to begin with and furthermore it is not much of an output at all because it needs pull up resistor so that the FET gets real voltage that it needs.
So please give the explanation that is actually needed. How on earth does your NPN transistor or your N channel FET make this possible as both are turning on with pull up resistors and therefore actually turning off when magnets pass the hall.
I am not an educated man.
Hello, please don't let me hanging. Thank you.
@@alchemy1 The NPN transistor (2N2222) is acting as an inverter so that the IRL520 is turned ON when the magnet passes by
dave
@@DaveBodnar So what you are not saying is that when the magnet is not by the hall the transistor is on. This causes the current form R4 along with R3 to go through the NPN to the ground, thus the FET is off. And when the magnet is by the hall, NPN is off so at the point voltage is available for the FET and since both R3 and R4 is same value, the same voltage exist across them and that voltage turns on the FET.
With respect to the Hall, when the magnet is not by it, the current flows through R2 and R1 into the NPN base and when the Magnet is by the hall, the current goes into the hall sensor itself through its signal wire. In other words, it's signal wire is actually a path to the ground inside the hall and not like some output positive voltage.
Are those what is happening?
@@alchemy1 I do not have time right now to revisit this project to be 100% sure but I believe your are correct
i think it must not neccessarily be magnets beeing glued on the spinner.
but any item that can receive induction currents might work.
maybe even the bearing in the spinner's arms could do it.
the forces would not be that strong but for keeping a spinner turning stronger than its friction it could be sufficient.
multiple coils could work for making it a more constant force.
doing longer current phases could also work for giving more permanent power.
as the spinner's speed is typically changing not only the turn on point should be nice to select
but as well the turn off point. so a second sensor and an R-S-flip-flop could do much of the desired works.
(Other folks would even go for a micro controller. just point out where the "uphill" road for the more complex design could be.)
Alexander, all good ideas and valid points. I look forward to seeing where others go with these ideas.
Thanks
Dave
If one added a magnetic current generator to the spinning piece, could it generate enough electricity to just give the impulse for the motor to keeping spinning?
I guess it shouldn't work, otherwise you had a self sustaining motor, in other words perpetual motion.
Sorry, Steve. But you would be violating several laws of physics if that worked!
Dave
it could preserve some motion i think but otherwise it would not be sustainable
What's an easy way to control speed other than variable voltage
Other than changing the voltage you could change the position of the sensor
@@DaveBodnar thank you, I was trying to think of something to control with a knob. I'm powering using a 5v system. 5v electromagnet.
Hold up, how did the LEDs cut on? I didn't see a power source to the breadboard.
There is a connection to 5 volts that powers the breadboard - if you look closely at about 1:10 into the video you will see a red/black pair of wires going off of the back of the board.
dave
Awesome now if you had a coil below everything you could theoretically produces more voltage than it wpuld take to run it. Passing through a transormer you could essentially allmost make a self sustaining generator......??? Can you send me one of these setups? Lol
No can do as we would be violating some laws of physics!
dave
This is damn cool !!! :) I like this a lot :) greetings from bavaria :)
Thanks for letting me know, MisterK -
dave
You should try regulating it with a little microphone as the sensor.
Interesting idea, Atlas - I am not sure it would work but might be worth experimenting,
thanks
dave
So tell us Dave... How fast have you pushed it? ;-)
David - I never pushed it beyond what is shown in the video - inexpensive toys with questionable quality control tend to self-destruct when pushed too far!
dave
That's when you ask for a young volunteer from the audience! (jk)
ROFL!!! that one made me laugh
Haha, at 88 comments, I have to say "Roads? Where we're going, we don't need roads!"
I built my own version of this, but slightly *BEEFED UP* you dont need to invert the signal from the hall sensor, i just connected mine straight to a mosfet for the coil and it works great. I used 16awg magnet wire for my coil and ran it off a 2s lipo and used a giant heat sink on the mosfet. Once i had finished it, i was super excited to try it out
1:56
I forgot to glue the magnets on
One flew off and almost dented the wall
GLUE YOUR MAGNETS
Enought said
Excellent work - thanks for the report and the reminder that the magnets can become missiles!
dave
@@DaveBodnar *UPDATE*
Super glue is NOT ENOUGH to hold the magnets on. I used a combination of gel glue and then normal super glue to fill in any cracks. After hooking my masterpiece up to a 2s lipo, it sounded like an f1 flooring it, as the spinner revved up. Until the point where super glue was not enough to hold the magnets on. One of them flew off (luckily it missed me)
My advice if anyone else wants to make a beefed up version of this, build some kind of guard around it and stand very far away
I fully agree - I have been doing some additional experiments and have been using magnets that have a hole in the center so that I can use a bolt to hold them on. Glue is not enough!
Stay tuned for a new video showing some new ideas.
dave
@@DaveBodnar update #2
I successfully secured the magnets with more superglue (enough to hold them on) and put an acrylic guard around the apparatus. The magnets haven't flown off, but i have encountered a new problem. I have reached the maximum speed of the bearing. Once it gets to a certain speed the bearing will vibrate, and make a ReEEeeeEeeeE sound and slow down. Im going to try and get some ceramic bearing to see if that helps. I know my motor is capable of more speed so im going to try to get to the point where the spinner itself cant stay together. (With safety equipment)
I have seen the vibrations as well. The bearings are inexpensive and prone to such problems. You could try a different brand spinner or even a bit of light weight lubrication or graphite to smooth things down.
Have you measured the speed of rotation? My best speed so far is a bit over 5000 rpm - not bad and a bit scary when it spins at that rate!
dave
If you replace the LED with a laser it would probably be a bit more precise
It’s time for the megaHURRRRRRTZ!
Anyone noticed that the loading animation is a fidget spinner spinning?
U should make it go super fast to the point of critical failure
im off to goo make fidget spinner great again
Let us know how it works for you - enjoy!
dave
I caught another video where a fellow was using a laser pointer to illuminate some clear marbles for an interesting light effect. (That vid is here: ruclips.net/video/ZvislxtabcI/видео.html) I was curious if you had ever thought of integrating something such as that for your brushless fidget spinner project.
Very cool, video, Shane - I may give some of the ideas a try
thanks
dave
Well clearly if anyone can, you certainly could. Thanks for the wonderful vids. Very enlightening and resourceful. I bet your students appreciated you. Take it easy Dave. Subbed.
use pickup coil instead
use bismuth in your spinner outer cups and use only a magnet better neo dim
Does this work with perpetual motion? If so, what kind of battery you could recharge?
Thanks!
No perpetual motion here - just simple physics - it surely doesn't go without adding quite a bit of power
dave
Thank you for the quick response, Mr Bodnar. It is impossible to generate more energy in a system than what it consumes. If this were true then the device would be running in overunity mode and would be over 100% efficient which is impossible. However it is completely possible to generate more energy than what the device consumes if the local enviroment is involved or some other energy that is outside of the system which can be drawn or attracted into the system. Namely the power of magnets. Any wisdom to talk about that for young inventors like me? I'm working in this for very long time You have great inventions!
F P there are plenty of examples of systems using external energy. Look at wind turbines or hydrogeneration. There is no magic way to just suck energy from the air.
F P If you add a coil top and bottom of each of the other 2 arms you can collect the voltage spike generated off each of those 4 coils as it passes the magnets into a capacitor bank or rechargeable battery. You can also capture the back EMF voltage as the field collapses off all 5 coils if you want more output, and more output again is gained by adding more arms and coils. Some food for thought for you.
Doing so would create drag in the form of a opposing magnetic flux, therefore requiring more current from the power supply, there is no free energy to be taken from this or any system.
100 rpm? More like five times a fast I guess. For reference: this is 100 bpm (beats per minute): ruclips.net/video/6GFTNEbu2FU/видео.html
If you look on the website he posted, it's spinning at about 1400 rpm
you forget that there is three arms
You need to try a pulse circuit. Read www.nutsvolts.com/index.php?/magazine/article/august2012_Williams on a solar powered pendulum. It will pulse the coil so as to repel the magnetic each time it passes under the coil. No need for a timing circuit like your light or hall effect stuff.
Thanks, Jim - I'll look it over
dave
Real life Rick