/sci/ - Science & Math

>gravitomagnetic arc reactor

>>4368821
Wut? I don't understand

Where are the magnets ? How are you altering the magnetic flux in the coils?

Well, most recently I've just been doing something like this. Put the magnets on a bolt and spin it around really fast. But in the past I've just moved a single magnet over each individual coil, and close as possible, and still nada

Oh, and about altering the magnetic flux, i've arranged all 12 magnets in an alternating-poles configuration before and spun them along the same axis as the coils, so... over the top of the coils, I guess is the best way to say it.

How do magnets work?

>>4368904
Same way an internet does.

idk, maybe theres somethign wrong with your measurement setup. Do you have any LEDS available? maybe try hooking one of those into the output of the coils and see it it lights up.

Woah woah woah OP. Are you basing your designs on anything at all? Cause it seems to me at an off hand glance that you're not properly directing the flux through the coils. Plus mounting the magnets on a metal object is gonna fuck with how they interact with your coils.

Honestly AC can be done easier by spinning the coils around the magnet. Have you considered that approach?

Of course this is all afaik from a physics undergrad.

>>4368808
> contingency
Continuity, please; it's about making a circuit pass current, not about evaluating risk.

>>4368921
Had some, but they went missing... in the short while I did have them, I tried hooking the LEDs to the thing and they didn't do a thing.

>>4368925
Yeah I know, I'm really not basing the design on anything at the moment. I really just want a proof of concept right now, It's one thing for people to say "Passing a wire through a magnetic field induces an electric current" but it's another thing to actually do it yourself. If you have an idea for keeping the magnets stationary and the coils moving, i'd love to hear it. I just didn't want to deal with the pain of slip-rings.

To be honest, OP is getting a bit discouraged by something so simple not working right

>>4368935
Continuity* My mistake, /sci/

>>4368873
The magnets have to be aligned so that the field passes through the axis of the coils.

Moving a magnet over a coil shouldn't do anything: you are supposed to move the axis of the field thru the axis of the coil.
Direction is meaningful, here.

>>4368808
>> i've arranged all 12 magnets in an alternating-poles configuration before and spun them along the same axis as the coils

Does this mean that you had a "ring" of magnets and spun them on top of the coils or what ? If so, then you should be fine. You need to change the flux penetrating the 'normal' of the coil. Check out some stuff on faraday's law just to be sure.

http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

ps. I've managed to light leds with nothign but a magnet and a few feet of copper wire by just jerking the magnet out of the coil quickly, if you aren't doing some major mistake you should see the induced voltage pretty easy.

>>4368969
Yes that's right, I used to have a second disk which 12 magnets mounted on and spun freely over the disk of coils.

So then /sci/, if I tape one magnet to my desk and levitate the other in the air, when I pass one of these coils through it I should get some sort of voltage, right?

Okay so here I have a neodymium magnet duct taped to my desk. A coil sits on top of it, and in back there is a pen with 2 magnets on it, held together by their magnetic pull.

If I were to spin the pen's magnets along a horizontal axis over the coil as it sits on top of the magnet, then it should induce an electrical current right?

>>4368808
Yes but I doubt you can spin it fast enough, just place the magnet on top of the coil and quickly jerk it upwards. The fast change in the magnetic flux through the coil lwill induce a temporary voltage.

Now that I look at your coils though, they seem very small and the wire looks thin, also your magnets seem quite weak.
If you cant get a voltage with the 'jerk' method I'd maybe think of making bigger coils, and / switching to stronger magnets,

>>4369065
Also, you don't need the magnet taped to the desk.

you should use one of those meaty types if you are going for fast spins.

>>4369065
OK, do you have any idea in which direction the axis of the magnets on pen are?

If not, why are you even continuing?
You need to work this out, and having two magnets isn't helping you.

Second, the coil is small; one side isn't appreciably going to be affected differently from the other side.

Third, the motion of the magnet needs to affect the coil directionally; so it's orientation and direction are relevant.
You seem to be ignoring both of those and just going with nearness and rotation, before understanding axes OR direction of the fields.

>>4369113
Well I'm not going for anything right now except progress haha

But I tried it. the magnet taped to the desk. Didn't get anything (I'm running the current through a diode, to measure it in millivolts DC. Don't think thats a problem though)

But yeah.. do you guys think it may just be the wire? It's 30g enamel-coated magnet wire

>>4369156
I'm listening

>>4369156
I think it's just an issue with communication, I'm sure he knows how to rotate them...if not... then check out this retarded animation:

http://www.edumation.org/play_file.php?file_type=animation&file_id=50

>>4369169

Don't most diodes require a bias voltage of ~0.7 volts to pass current ? I doubt you'd get much over this from your little contraption so lose the diode.

I agree I think there is alot of miscommunication going on. I know the basics, but the idea isn't working. I can safely say I can move a magnet in any direction around any axis at any time and I am not reading a voltage. If I remove the diode, is there a simple way to see if voltage is flowing, besides a LED? I have none sadly.

Ideally you'd have an oscilloscope to see the pulses. If you have a capacitor you can try rectifying enough generated voltage to get a DC level on the multimeter.

Alright, well, thanks a bunch /sci/. I really appreciate the help, but I'm gonna call it a night. Have a good one, sci people

I'm confused about 'diode' --
you said you were using it to measure the current, so I figured you were talking about a voltmeter
But someone else just implied it is attached to the coil?

Why are you not using just a coil attached to the leads of the voltmeter?