effect of spin ?

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ryan.reeve

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HI

I want to know if there is any effect of spin over electronic circuit if it is spinning.
My circuit includes a very small atmel based microcontroller application spinning around 15000 to 20000 rpm.
Should it work just fine or collapse ?

regards...
 
Other than the mechanical integrity issues like balancing and accelerations due to rotation involved, external magnetic fields would induce currents in the circuit due to spinning. HOw bad it is depends on how sensitive the circuit is, the strength of the magnetic field and how fast you are spinning.

What type of circuit spins at 20krpm?
 
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If you have a system running at 20k revs then we are the ones with questions.

Please supply more details.

Mike.
 
I can think of aboslutly no application which could logically require active components spinning at those speeds. The G forces would be incredible. And like DK said a magnetic field nearby will induce currents. You could encapsulate the device in mumetal but even that isn't going to eliminate currents, nothing can do that. Generally speaking if you need a sensor on the motor shaft what you would do is some kind of slip color on the motor shaft to feed the sensors signal off the motor shaft, you wouldn't put the active components ON the shaft.
 
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A 4MHz pic can execute 3000 instructions per rev at that speed. But I suspect a POV display would run around 3000 RPM.

Mike.
 
Imagine what the collateral damage would be when something spinning at 20K rpms suddenly breaks apart.
 
Artillery shell fuze electronics can apparently experience at least 16,000 Gs.
Low Cost Competent Munitions [LCCM]

This is apparently due to launch acceleration. I couldn't find info about acceleration due to spin velocity. There is, of course, no appreciable magnetic field to deal with.
 
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Hypothetically, induced currents COULD cause a problem, but it's going to be fairly small unless the magnetic field is strong, the PCB traces long, or the circuit is very sensitive.

Questions of G-forces and "why??" remain.
 
That PCB is going to have to go through some very sensitive balancing.
 
Nigel Goodwin said:
At 20,000rpm?
Click to expand...

For the second axis. They use 2 powered axes, both have to be faster than the human eye response time so you run one at say 2000 RPM and one at 20000 to 50000 RPM. Together they scan a 3D area for a visual display.

Imagine something like a TV horiz and vert sync but done mechanically.

I remember someone tried to build one years ago and had the motor speed and power but the G forces on parts of the machine were in the hundreds of Gs.
 
try to keep the circuit so closer from the axis of rotation. the centrifugal force due to circular acceleration is proposanel to rw^2 where r-radius w-angular velocity. so by minimizing r you can some what have mechanical stability, also less intersection to megnetic fields. short interconnection would help to reduce effect of induction.
 
RB it would require balancing the typical hobbyist couldn't provide to keep vibrations from destroying the circuit in question. It would also be dangerous as hell..

I have a Dremel tool that goes to 30,000RPM and over about 15 you have to be very careful about what the bits are made of, and they're only about 1 centimeter in diameter. And entire electrical circuit is hardly practical, and strapping something like that to a motor shaft would cause some pretty large imbalances. I don't see how something like that could be practically made and not be a threat to anyone near it.
 
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I agree completely!

Which is probably why (as far as i know) nobody has finished one and put it up on the net.
 
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