TPU - General Discussion

[BEP]

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[EMdevices]

All

Have you wondered why you need the DC bias?Ã, 

If you've built oscillators and amplifiers you will understand.

EM

[EMdevices]

Here's the magnetostriction chart again, showing the changes in the driving current producing the strain or change in length.

EM

[Esa Maunu]

@Esa Maunu

If you use a helical coil around the magnetostrictive rod, it does not create linear lenght changes for this rod.
Helical coil creates a twisting  effect and torgue for magnetostrictive rod, this phenomena is also known as Wiedemann effect. ...

Esa,  I disagree.  The magnetostriction phenomena involves a lengthening of the material ALONG THE ORIENTATION OF THE MAGNETIC DOMAINS, and I'm sure you know that a solenoidal coil produces a AXIAL magnetic field, hence the lengthening happens along the AXIS or the length of the rod.

The Wiedemann effect is something else, but quite related.  that's where you impose a radial external magnetic field at, for example the middle of the rod, like I showed in my previous postings. 

EM

It depends if you use helical coil or just solenoidal coil. In your picture it looks like helical coil. but even if you use solenoidal coil and apply a current in to this rod, you can get a twisting effect. On the other hand i don`t think that this produces OU. But who knows..

http://en.wikipedia.org/wiki/Magnetostriction

Esa

[BEP]

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