Electro-Mechanical Resonant Oscillator
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- Опубликовано: 26 сен 2024
- In this video I'll show how to build a resonant mechanical oscillator that's driven by an electromagnet. The electromagnet is pulsed by a circuit
with an adjustable frequency, so it can be fine tuned to run at the exact resonant frequency of the spring-mass system. In this case that
frequency is about 11 Hz. The driver basically just consists of a 555 timer and a MOSFET to turn the coil on and off. In the future, i think i
need to use a feedback controller to do this, because even when i get the system to resonate, it eventually drifts out of phase and resonance
dies off (even though the frequency is matched).
This type of device is commonly found in the compressor section of compact cryocoolers for infrared imaging and other sensors that require
extremely cold temperatures to operate. Suspending the compressor pistons on a flat spring or "flex bearing" and driving them at resonance allows
for high power and efficiency even with the relatively weak forces between the magnets and the coils. This is analogous to a flywheel on a
crankshaft, but is lighter, smaller, and more reliable. By avoiding the need for the bearings and linkages present in a rotary system, this kind
of devbice can achieve an extremely long service life (some are rated for over 200,000 hours of operation) inside a hermetically sealed unit.
This is part of my investigation into building my own refrigeration system (and eventually cryocooler) without HFC's/phase change refrigerants.
Several months ago i made a video showing how i built a compressed air turbine which I intended to use as a Brayton cycle cooler, and while it
did work, the extremely loud noise made it impractical in a home environment, so I'm now investigating reciprocating systems like Stirling/Pulse
Tube/Thermoacoustic/Gifford-McMahon-type devices for generating extremely low temperatures.
Music Used:
Kevin MacLeod - George Street Shuffle
Kevin MacLeod - Groove Groove (Yes, this is the same song that's in Kerbal Space Program)
STL Files:
www.thingivers...
Metal Spring DXF file:
drive.google.c...
Driver circuit schematic:
drive.google.c...
Further reading on cryocoolers:
www2.jpl.nasa....
www2.jpl.nasa....
Fabrication shop i used for the metal springs:
sendcutsend.com/
Hey guys, thanks for the comments. When I develop this into a linear compressor, I'll definitely be adding feedback to keep the resonance on frequency/in phase. I'll be using either a hall sensor for magnet position, or detect zero-crossing events on sense coils.
why dont you put sound through it see if you get some as its basically how a speaker works.
@@jediknight2350 You would't hear it
given you're turning it into a linear compressor, aren't you effectively making the inverse of Tesla's electro-mechanical oscillator, given he used steam/air pressure to create electricity, and you'll be using electricity to create pressure? (patent US511916)
Plz use metric si units.... the eng moved away from potatos vs tomatoes plzzzzz . . Your videos r great.
@@andretokayuk8100 bģ
Your jokes have the perfect resonant frequency for a nine and a half minute video. I really enjoy seeing you build things like your own winding rather than buying one.
It’s pretty wild that sterling motors are still a valid tech these days. Sweet build man.
A stirling powerd supmarine defeated part of the American fleet in a war simulation
Han Solo's voice speaking about electromagnetic fields. I am subscribed.
super simple concept yet incredibly entertaining. absolute gold. also insanely smart to use it as a pump like that, cryo stuff is amazing. thank you for the amazing video!
The information density on your videos is ridiculous. Awesome projects!
Absolutely brilliant. I'd hoped this would be a build that measures its own resonant oscillation - in other words, add more or less mass to the coil-spring platform, and have it PID (or even just P) tune itself to the new mass. Such a thing would be surely handy in its own way for damping 3D printer oscillation resonance. But, even though this was different than what I'd expected it to be initially, it's still tremendously wonderful work.
Side note - you've already SendCutSend'd the springs, so it's too late for that build, but on the next one, consider making your spring coil width taper off with a slight logarithmic reduction as you approach the center of the coil. This will evenly distribute the flexing across the full length of each spiral, rather than the rather visible issue of the center of the spring not flexing at all, and the outside of the spring overflexing.
I was also expecting some kind of feedback. You could use it to adjust the frequency as well as the amplitude. Tweak the frequency. If the amplitude goes down reverse direction. Tweak frequency until the amplitude is greater than desired, then reduce the power fed to the coil until it's lower than desired, then tweak the frequency again. Repeat until you overshoot the resonant frequency and the amplitude starts to reduce. Then you can sweep slightly back and forth over the resonant frequency to see whether it drifts.
What an ... exciting project ...
thank you, I'll be here every saturday fro 3 to 5 pm
I saw a real example of this in a 1950s piece of military tech it was a mechanical oscillator/voltage converter. Self oscillating solenoid with adjustable points and spring, and a coil windingnrectified to produce a high voltage.
It was used as an "inverter" to power high voltage tube radio equipment from a low voltage DC source like 24v.
That's where all the 'good stuff' is. For sure. 40s,50s, early 60s, then things start getting bogged down in over complexity, Fkn 1938. Damn the 80s. 2 steps forward, 3 steps back. Cool World, 1992. That's a banger.
Very nice to make some standalone thing for testing a part of a bigger system, I really like this approach.
Thanks for the cryocooler links, I'm also interested in building a DIY version of one that is able to atleast liquify air.
Liquify air? Sounds like a really "cool" experiment!
Great project, you can turn this into a actual oscillator by creating a feedback driven circuit.
For sensing the position, you can use a loop of wire with a current to voltage converter or a small proximity sensor.
A PID control system with opamps can also be implemented.
Really nice project.
Thanks & Cheers
I'm so glad that i found your channel. Keep going!
The smiley dude is me on caffeine
Congrats! You just made the guts of a speaker!
this would be a good testbench for inverted pendulum shenanigans. I saw a thing that showed how inverted pendulums on oscillators self-stabilize upright at the right frequency.
Yeah, you know what this is similar too. Brutal. I love it.
Cute little project! I can see that would be something to shoot ball bearings to a good height on a marble course or drawing in and shooting out short streams of water like those 'bouncing water streams' at Disney World I remember seeing.
I've recently been learning a bunch of concepts that are present in this video at school! Awesome project.
Solid video, love the quick prototyping of the control problem. We are trying to try to cook up a free piston engine over here as well. MOTŌR smiles upon you, sir. Subbed.
Seems like it would be useful for a range of applications
love it, i know what kind of toy i will be building for my wife this Christmas for both of us to enjoy.
Dude just made a subwoofer from a tennis ball :) nice work on this video.
Impressive concept put into practice. Thumbs 👍 up. Vast prospects in radionics also.
The smile drew me in
i love the snickering and inuendos, keep those
Excellent work.
memory foam beneath the weight mount would work as dampers say if hammering/jumping effect isn’t desired on ground contact.. the spiral spring is really neat, though a round silicone film would be be more resistant to damage from constant vibrations.. also could add secondary pickup coil as a generator.. wonder if a small oscillator can drive a larger one? inspiring work!
I loved the googly eyed head bobbing so quickly. Good stuff here.
A very interesting project. I was expecting closed-loop control but it turns out to be open-loop. It has finally occurred to me that your voice sounds very much like Jamie Hyneman (Mythbusters).
This is really cool! Just be careful because infrasound can be very dangerous. You can make yourself sick if you are too close to an infrasonic pulse, and if it’s amplified, it could even kill you.
The barbell weight is probably cast iron instead of steel. If you used any liquid (oil, cutting fluid, WD40, etc) it would almost instantly dull the drill. Cast iron has tiny grains of iron carbide in it which mix with the liquid forming a slurry similar to lapping paste. Drill cast dry. Cool with compressed air.
I did not know that. Thanks!
Just need a way to replace the smiley face with a container that can hold a small paint jar. You just made a perfect mixer for hobby paints with this contraption.
If you want to make it better you could develop the electronic part of the project to self-find the resonance. It coud be easily done by adding one more coil to sense the field (magnet position feedback) and one LM311 or similar comparator. Feedback could be also done via some 3 terminal hall sensor. In mid 50's they made clocks simply by making blocking oscillator with single transistor and the core of the blocking transformer was made resonant in some way. Eather by coupling it to small tuning fork (and then dividing oscillator pulse via flip-flops) or coupling it to a pendulum with a magnet and dividing pendulum movement mechanically...
To complicated. Just add a magnetic reed switch to break the circuit then all you need is a little power sorce. Nothing else. Car radios worked with tubes dependably using simple viberator to pulse dc then feed pulsed dc to step up transormer for the 80 volts needed for tube plate bias. No transistors or ic's needed. Just a simple device. Tesla almost shook a building to pieces with a pneumatic mechanical vibrator that worked in a very similar way. Also kit kat clocks have been wagging their tails and looking shifty eyed using the same electrical mechanical resonant vibratory circuit for many many years. Meow. Also, if you have some huge stones to move ,a certain man who built the coral castle in Florida had an interesting version that he created to do manipulate very huge stones.
My dad has a wall clock that works like that, and it's always fascinated me.
That's all a bass speaker is. The cone is designed to hold the cylinder in midair, where it floats, and can deflect up and down, over a magnet. Then you just put an oscillating frequency (sine wave) pwr. into the coil, the coil reacts against the magnet, and, up and down you go. It's magic, 120 year old tech.
To be able to hear the bass with our human ears, you need a minimum of 40 to 60 hertz. The human hearing scale is from 40 to 60 hertz, up to upwards of 20 kilohertz. 40 to 60 HZ will just give you a headache, 20 plus kilohertz can damage your ears, when the decibel level is very high.
Add a positive feedback loop that just reads the voltage of the coil and kicks the system at the right moment to sustain the natural oscillations. A small MCU or arduino can do the job.
I appreciate the KSP ambiance. ;)
This channel is so cool. How do you have so little subs haha that will probable change soon !!!
Probably you can get some ideas of building feedback loop from ultrasonic bath schematic. It also tries to keep resonant frequency.
Your way ahead of me so this is to be expected. Good work
Now where are we going hahaha
8:13 kinda cool how the frequency at a point almost looks like a Cool S that we all used to draw
This gave me ideas…
4:45 you can say it loud!!!!well done
Fascinating! And I didn't snicker once.
Nice paint rattle cam shaker.
Next level material.
I rebuild Sumitomo ColdHeads (Cryo coolers) that maintain 0% boil off of LHe in MRI magnets. Our "RDK" Coldheads have two stages inwhich the 2nd stage goes down to 4 Kelvin under load in order to recondence helium vapor that naturally wants to boil off back into a liquid.
The Sterling effect that achieves these temperatures is generated by a compressor that brings the He to close to 200 PSI while a motor whose high to low pressure value is guided by a grease filled shielded Z bearing.
The only springs you'll find in that entire system is to space the supply line
Also, it's ENTIRELY possible I misunderstood, but it sounds like you're under the impression that a Cryocooler is the compressor? But instead, the Cryocoolers requires an external compressor to compress the He gas in order for the Sterling Effect to move the displacer and extract heat through a system that is analogically closer to a Thermal Acoustic System (See "Nighthawk's video on Sound Refrigeration).
The systems I'm talking about are usually small self-contained stirling cycle coolers that get attached to some sort of sensor like an IR camera that needs to be cooled to ~70K or so.
I'm guessing the cold heads you're working with are the "Gifford-McMahon" type that are basically a modified stirling cycle where the cold head goes in a dewar and it's connected to a separate compressor unit by some flexible lines?
PS, if you happen to know where i can get some reasonably priced spares/surplus of the kind of equipment you work with, send me an email, cause i've been trying to build a cryocooler forever
If you add a model of the new Shepard instead of the ball you have a super nice looking lauch simulator
The lack of si metric standard makes a mess that makes me strugle alot. But beyond that great video i hope u get more and more views
I love these infinite energy generators
Not infinate, Conversion energy
4:26 The sound of my washing Machine 🤣
The width of the coil should vary either in its thickness or in tapered coil to center. You have rhythmic vibrations your dealing with young Sir.
And here I was thinking I'm the only person who reads NASA cryocooler literature for personal enrichment!
Awesome this is very clever
Cool! Now take the upper portion and apply friction that shows it become damped/overdamped/critically damped for all the engineering nerds
If you model ridges alone the spring on top of it and optionally the bottom then you can stiffen it too.
The stack of springs also limits sideways rotation of the 'pendulum.'
Strictly speaking, this isn't an oscillator. It's a resonant system. Now, if you arranged some positive feedback from the sprung weight to the driver circuit it would naturally oscillate at it's resonant frequency with no frequency adjustment required.
Pretty cool bro.
how you make an adult toy
This excellent. Are you going to release a video incorporating a feedback circuit of some kind to keep the resonant frequency in phase ? Thanks
Turn this into one of the thumper machines in old Dune movie.
my homeowner's insurance doesn't cover sandworm damage
Is that a specified exclusion clause or just an assumption?
Why does a ball with eyes moving up and down make me laugh so hard??)))
It's that big grin smile
This is insanely similar to a speaker
Maybe you should talk to a tattoo artist and ask how his machine works.
I'm gonna try to make something like that. A function generator along with an amplifier should probably do the trick. Making an efficient electromagnet might be more tricky though
amazing,,you are so smart
KSP music...top!
9:00 "because phase of the motion would drift from the phase of the driver"
That's not how it works. Resonance implies very little losses, hence if you're just near the natural frequency (how far off depends on Q) the driving solenoid will have no problem syncing the phase by pulling the magnet earlier or later in the cycle.
Congratulations, you built a subwoofer
This is an _excellent_ video, both for the topic / content _AND_ for the process / production values : Thanks !
¶
I wonder what is the Q of this tuned circuit. ¶ If you revised the feedback to be _closed-loop_ and coupled the output to a display (either electrical -or- "analog"/mechanical) the long-term frequency stability would likely be quite good. ¶ It is likely that some "direct synthesis" would be needed to convert the pendulum's frequency (¿up or down?) to some useful frequency. Perhaps several flip-flops with suitable feedback would do it -- if you were lucky -- but it is more likely that synthesis with a PLL (=Phase Locked Loop) would be needed.
§
Over the decades, I have built several closed-loop mechanical pendulums to drive numerous salvaged clock faces, nixie tubes, and Solari® panel. [It had been discarded from a RR station in Tuscanny.] One used an 8" woofer speaker with a laser-pointer reflecting off the cone. Another used an opto-interrupter -- as an "light-beam breaker" -- as a zero-force micro-switch. This was a simple mod to a long deceased "flying pendulum" [=FP] clock. (See Wikipedia if this term is UNclear; YT no longer permits URL's in viewers' comments.) The FP mechanism was likely pre-WWII. The gears, mainspring, face, & hands were useless. I used a 3V motor from a small toy car to provide constant tension for the arm of the FP. This clock had a 1-shaft FP; many clocks use a 2-shaft design. NOTE: There are _many_ YT videos which show an FP mechanism. I used the FP from an existing clock because it was in _good_ condition (including the fragile "pendulum string"!) _&_ because building a working FP was / is far beyond my builder's skills. ¶ I hope others will find all this noise interesting and even useful!
¶
Thanks, again, for this 4⭐ video! ... /Mike - eot - _..._
the glaggle torture device
Can you make a quartz clock, but with this instead of a quartz Crystal?
Seems the inner part of the spring deflects way less than the outer part, modifying the width of the spokes so its thicker on the outer may give you a better performing spring
Lie a speaker on it's back and turn the amplifier up.
This seems fun. As a side note has anyone 3ver said you sound a lot like prozd?
You can let the 555 adjust to a sensor of the current jump frequency.
Super interesting
Thanks a lot!
Perfect
You should also make the circuit resonant at the same frequency
always wondered why they made that noise
Could do the feedback using a piezo underneath the whole assembly.
Always some sort of load on the top, for sure.
Thank you for the share.
Hall effect feedback sensor and PLL would be more interesting
This almost reminded me of tesla lost earthquake machine, just a speculation
Congratulations you've made a poor man's base shaker .
Muy buen oxilador,ingenio puro,más conocimiento,,.😃👍🇺🇾
Applied science had one of those on his cryo finger
Спасибо, вы делаете интересные вещи.
Расскажите пожалуйста, как можно сделать линейный генератор на мембранах с приводом от двигателя Стирлинга.
Can you also make galvo ?
A curiosity.
Some thoughts come to mind. Would the barbell steel still be as "jumpy" with a system designed at a higher resonant frequency? Is it possible that your oscillator is merely near a harmonic of the steel against the floor?
Maybe it would be possible to alter the tension of the spring so that on the upstroke it's travel is limited, but on the downstroke it has more range. Perhaps by simply adding a plate above the spring to prevent it's motion. As I see it, the barbell is absorbing the energy of the spring, but at 180 degrees, and with much less motion due to it's larger mass. But if the spring transferred more force on the upstroke than the downstroke, wouldn't it stand to reason that an object's weight could be reduced?
First of all a harmonic only concerns acoustic sound, secondly, you would need a very high frequency to reach atomic resonance. Water is 2.4 Ghz
Cool!
Do be careful, when Nikola Tesla made something close to this design in New York, in his hotel room in a large building, he was able to match the resonating frequency of the building itself. It shook with great ferocity, the owner called the police to report an earthquake only to find it was just his building shaking. The device you have created has a great deal more potential on the macro scale.
I always wondered if resonance was how the pyramid builders moved massive stones into place. How were they planning the pick up a 1200 ton granite obelisk out of a quarry site and move it?
I skipped around the video, so maybe I missed it, but how is this different from a speaker (except it isn't doing a good job at playing music)?
Where can one source the cut file for those springs?
Also, isn’t this or something similar what Tesla used to shake a building?
The spring seems to have more give in the outside than the inside...possibly you need a different geometry.
1:28 "Boing-y" is a hilarious word for the evil that torments our laser CNC operator every day, boingy sheet steel reflects laser into the iris, which is very expensive.
Very cool
That's all right I can't hold it.... The joking starts now 🤣😂