Mechanical Resonance (Projects)

[Magluvin]

Acoustic resonance is a mechanical resonance, so it can't be TOO far off topic.
You don't want resonance inside your car with a powerful stereo system.
It makes it hard to drive.  (29Khz, and again around 7.9Khz)
Oddly enough, both frequencies are ~resonant with both the cavity of your car and the cavity in your head.

@ Brad
nice test!
I know I posted some 124Hz or something in the video, that was mostly my brain spouting out a senseless number..
When thinking about it,

You should follow a scale, something like:
11.2
22.4
44.8
89.6
179.2
etc.

[Edit: the half-wave below 179.2 would be 134.4 - this may have been where my mind went on YT, (Blurp!)]
   so this was an incorrect place to go, since the 11.2 is ALREADY the half wave...
   I forgot to take into account, the mechanical restriction
  the wave bounces back forming the  "standing wave".
  full wave would include the negative (-) portion.

Been thinking about making a shorter plate and would have to make a strong holder for the magnets because of the back and forth speeds at higher freq. Im sure we will get into it.   


Any help here is very welcome.


Mags

[MagnaProp]

...Check this out...
https://www.youtube.com/watch?v=7wD6aDzEVdQ

Nicely done.

I'm curious what happens when you move the driving electromagnet up or down the length of the resonance rod?

[tinman]

I have switched to a spring steel oscillating strip,and this has raised the frequency to around 33Hz.
I can now draw more energy from the system,and at the same time,the system consume's even less power than the first one that operated at a lower frequency. With this small rise in frequency,the P/in without the oscillating strip in play,is the same as the first test seen in the video.

My first thought was that the oscillating magnet was lowering the impedance of the coil,but in order for that to happen,the PM field amplitude would have to rise before the electromagnetic field produced by the coil--the PMs field leads the electromagnetic field,and this cant happen,as it is the electromagnetic pulses that are acting on the PMs field in order to create oscillation.

This is pretty much the same results i seen with the pulsing coil tests i did,with and without the rotor with PMs embedded in it,that rotated in sync with the pulsing coil.

there is something else going on here,and we need to find out what it is.


Brad

[Magluvin]

Hey brad

Just a curious thing.  When we have say 1 subwoofer and it plays at 100db at 100w, and if we add another sub at 100w we get 106db. Now, it takes a doubling of power to make the single sub get to 103db. So from what I know, we can run 2 subs at 50w each, same total power of the single sub example and we will have 103db. Do you see the advantage???

So, if you happen to have another drive coil just like the one you had shown in the vid and put it on the other side of the mast, then put it in series with the other coil for a push pull config, at the same total power input (will have to make voltage adjustments to get the same total power), you should get more movement of the mast for less input.

Would be interesting to see.    Lol, if you put 25w each to 4 subs, you get 106db.  12.5w to each of 8 subs, 109db.

So now, if it works with 2 coils in series and the pendulum moves more, then I suppose we can count on even more savings from the pendulum movement.

Hope I got that right. Have to go. didnt eat today yet.


Mags

[Magluvin]

Hey brad

Just a curious thing.  When we have say 1 subwoofer and it plays at 100db at 100w, and if we add another sub at 100w we get 106db. Now, it takes a doubling of power to make the single sub get to 103db. So from what I know, we can run 2 subs at 50w each, same total power of the single sub example and we will have 103db. Do you see the advantage???

So, if you happen to have another drive coil just like the one you had shown in the vid and put it on the other side of the mast, then put it in series with the other coil for a push pull config, at the same total power input (will have to make voltage adjustments to get the same total power), you should get more movement of the mast for less input.

Would be interesting to see.    Lol, if you put 25w each to 4 subs, you get 106db.  12.5w to each of 8 subs, 109db.

So now, if it works with 2 coils in series and the pendulum moves more, then I suppose we can count on even more savings from the pendulum movement.

Hope I got that right. Have to go. didnt eat today yet.


Mags

"you should get more movement of the mast for less input."
Here I should have written for the 'same input'.


Mags