Shulie TornelQuestions Doc: https://docs.google.com/spreadsheets/d/19bZ6CqzGPlrbwcTaaXK_Mt0NeD2cc1AXOPVKKPWIkxw/edit#gid=0
Jeremy So I'm a mechanical engineer by day, and tinkerer by night. Currently leading prototype efforts on the mechanical side at Nanomagnetics. Free time currently is being taken up by autocross, but I have a few side projects I've been kicking around to pick up when I have the time as well!
What kind of side projects?
So the last major project I was working on was making my own headphones.
Cool, did you design your own magnetics for that?
Unfortunately no, mostly it was more of a mechanical side project, but I did liberate a pretty sweet planar magnetic driver from the T50RP's as a base for it
Excited to learn about more usecases for magnets
hi Anil!
Jeremy @Anil Pattni ask away!
We have a question here on the doc: Researching about magnetic waves, not sure if you know about the magspoof device from Samy Kamkar. A device which implements a coil to transmit magnetic waves using certain format to be interpreted in the card reader, my question is do you know another way to generate that kind of waves but with using something different than a coil?
aren't those called "electro-magnetic waves" and usually generated with an antenna?
nopes, not there - it's a huge coil on an attiny, if I'm not mistaken
it's to fake magnetic card swipes
Yeah, but I think @Shulie Tornel is implying that it's all near-field.
I haven't taken a look at this magspoof device before, but off the top of my head, if you want to generate a strong magnetic field you'll want to run it through a coil
Hi @Lutetium@Jeremy are you using magnets for any of your projects?
magnets on a disc - spin the disc infront of the reader
how are the curved magnets made?
and when they are sold in pairs, do they have exactly the same amount of magnetism?
@Anil Pattni Currently working on a magnetic connector, it's designed to do USB 2 between devices
as for how magnets are made, they're typically sintered in the rough shape you'd want
Nice, If I placed magnets at specific intervals on two discs placed on an axle and applied a small current, would they continue to rotate on their own?
as far as strength, if you could control the process so that the magnets were precisely the same size and had the same compositon yes, they would but due to manufacturing tolerances they will differ slightly. But for the majority of cases you can treat two magnets with the same size as having the same amount of magnetism
@Anil Pattni Yes and no, what you'd want to do is apply a current to attract/repel the next magnet. and then turn it off. This is ends up being the basis of a DC motor. You can actually experiment with a magnet, some magnet wire, and a battery to make a rudimentary motor this way
@jeremy That's so cool, I like the apple magnetic connector and that their available for microusb too smartphones, I'd really like the practically of them for phones because we're always connecting / disconnecting
@Anil Pattni Re: your axle question. I'm not sure what you are describing, but have you looked into homopolar motors? Plenty of videos on Youtube. Takes about a minute to prototype a demo with materials you already have on hand
e: the curved magnet, does the amont of magnetism (what is that called ayway?) change due to the shape? or just the volume
@Anil Pattni That being said you'll want to run the current through a coil to generate a large enough magnetic field to have an effect on the magnets to continue their motion
re: the USB 2 magnetic connector, do the magnets affect data transmission at all? would connecting/disconnecting cause noise?
@Jeremy so if we use the face of a clock to describe positions, would magnets be at 1,3,5,7,9,11 on one wheel and 2,4,6,8,10,12 on the other?
@Jordan Bunker In our testing, not at all! As for noise, can you elaborate on what you mean by that?
Do have any experience of electropermanent magnets, or do you primarily work on magnets for power and data transfer?
@Anil Pattni If you were to only use permanent magnets, they would eventually find a resting position and stop movement. To keep driving the motion you'd really need to have something that can turn the field off
nteresting! I guess my thought would be that if the magnetic field strength increases as you bring magnets close to connections, does it cause interference with data lines. If testing shows no, then awesome :)
@Alex Williams not much experience with that, mostly working with electromagnets and permanent magnets. Those do look pretty cool though. Were you thinking of using them for a project?
@Jeremy how do we turn the field off?
@Jordan Bunker Ah gotcha! So as long as the magnetic field is static, meaning that it doesn't fluctuate it doesn't have any effect on data transfer
Anil Pattni @Soumen Nandy Homopolar motors look cool
@Anil Pattni You would need to use an electromagnet, you can't really turn off a permanent magnet, the best you'd be able to do is shield them
I was considering it - emergeny payload release for an underwater project, so if something goes wrong it can surface quickly
@Alex Williams So a dead man's switch of sorts?
Alex Williams Yeah
Realisitcally, I think I'm going to go with a permenant magnet within an electromagnet that can be turned on momentarily
@Jeremy Thanks, I will look into options.. :o)
Sounds interesting, so you're thinking of using a solenoid as a trigger?
Check out: NicaDrone OpenGrab
Are there any substances which can block magnetic fields without being attracted/repelled by the source?
@Jeremy I don't understand, do you mean as the release mechanism?
@Alex Williams You can use a powered solenoid to suspend a magnet above a ferrous block and if power gets cut the magnet and ferrous block can be used as a switch to trigger your surface mechanism
@Jesse Tolvanen The board is built together with the electropermenant magnet, which is less than ideal. However, it's open source so I could certainly look at their circuit and see if I can make a derivative board that is more suitable
@Alex Williams For a quick-release, have you considered two magnets separated by a thin flat coil (e.g. a spiral monolayer) that would oppose the two magnets when energized? If the two magnets were stacked (North South) (flatcoil) (North South) and the applied current created a (South North) field, it would greatly weaken and even repel both magnets. Unenergized, it would just be an inert gap. It's not a deadman's switch but it also takes much less power. once the magnets begin to separate their mutual attraction would decrease rapidly
@Jeremy The application that it is required for needs it to be as low power as possible (the purpose of the project is to use minimal power to travel long distances), so a powered solenoid would not be ideal, unless I'm misunderstanding
@Brian McEvoy Off the top of my head I can't think of nonferrous shielding materials. That being said, distance works very well. What were you thinking of doing? There's some materials that have a high saturation and high permeabilty that you can use to shield your magnets with and you won't have much or any leakage if you have a thick enough shield
@Jeremy I was hoping to "switch" permenant magnets. I guess Newton's laws win this round
@Alex Williams Ah, gotcha. In that case you'll want to use something like a reed switch to detect a magnetic field and have your failure mode set up to move the magnet towards or away from the reed switch
@Brian McEvoy When you say switch them, do you mean turn them off or flip polarity?
@Jeremy I wanted to turn them off.
@Brian McEvoy If you wanted them to turn off permanently... you could heat them up until they demagnetize :D Otherwise I'm assuming electromagnets are too big and require too much power for your application
Brian McEvoy @Jeremy I think what I wanted would amount to perpetual motion.
@Jeremy What's your favorite use of magnets that you've seen in a project yet?
Hi Jeremy, did magnets wear out? I heard about devices that appears to run forever, but in fact they are consuming (as in de-magnetise) the magnets. Is this true/possible?
@Brian McEvoy Electropermanent magnets are permenant magents that you can turn on and off by applying a current, Jesse mentioned NicaDrone OpenGrab earlier in the chat which is a low cost ($60) electropermanent magnet
Thank you @Jeremy and @Alex Williams
@Jordan Bunker I saw a project about a DIY MRI scanner that sounded really cool! Pretty ambitious but would be pretty awesome to see in action
@RoGeorge As far as de-magnetizing, magnets demagnetize quickly when high temps are applied to it (>90deg C) But as for these "run-forever" machines, losses typically occur in any wear/friction surfaces so any energy initially in the system is consumed by friction, not so much from the magnets demagnetizing
So that's all the time that I have for today! Was fun chatting with you all. If you guys still have any questions, feel free to message me directly! I'll be lurking around in chat sporadically as well
Thank you Jeremy!
Shulie Tornel Thank you so much for chatting with us Jeremy!
Jordan Bunker Yes, thank you @Jeremy!
Thank you @Jeremy. I know about Curie point and conservation of energy. What I am not sure is if there is any potential energy stored by the magnet in the proces of its creation (magnetisation), and if this energy can be harvested by very low friction machines, so the whole "motor" run for very long time
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