Prajna
Fixing things for the love of it
- Messages
- 523
- Location
- Castelo Branco, Portugal
How did you figure out that I'm planning to build it from that?!Not if you make it from unobtainium!
How did you figure out that I'm planning to build it from that?!Not if you make it from unobtainium!
Noooo, don't do that yet!Is that the energy crisis solved then ? Does it mean I can turn my heating up
@gaz1, I'm not asking for improvements to the design. Rather I am hoping for suggestions as to how the inductive drag on the disc relates to the power output of the system. We can optimise the design later, if it proves interesting but for now the design is simply for the purpose of demonstrating what I'm talking about.
Good reply, @hotponyshoes, but I'm not sure that Newton's 3rd law is the most useful formula to apply. Here we are mostly looking at magnetic forces and thus will need to delve into the theory of magnetics and any related rules.If the 2 magnets are drawn towards the rotor when in a 'solid' slot they will attract the rotor and a force will be required to rotate the rotor out of the magnetic attraction field.
Newton's 3rd law covers how much force will be required.
From that, you can work out that the force required to turn the rotor will be equivalent to the force required to separate the magnets.
Plus the addition of any force required to push energy into the magnets for them to do any work on the output side.
So A+B=C.
If A (field strength) =1
If B (work done)=1
Then C will be 2.
So put 2 powers in. Get 2 powers out.
Except you will loose power through friction so 2 in will = 1.9999999999 out at best.
Force is force. Magnetic or otherwise.Good reply, @hotponyshoes, but I'm not sure that Newton's 3rd law is the most useful formula to apply. Here we are mostly looking at magnetic forces and thus will need to delve into the theory of magnetics and any related rules.
If anyone is interested, I have also posted this over on the scienceforums. There has only been one reply so far (and no response to my reply to that) but if you're interested in following the conversation there, the link is https://www.scienceforums.net/topic/133616-curious-device/
Not sure I can agree with that. It might be similar to poking with a stick that has a spring on the end, perhaps. It's not a direct push that we're looking at here, rather there is a resistance on the input that is caused by magnetic drag and the output is caused by the switching of the magnetic field rather than being directly linked to the input energy. Once you start looking deeply into what is happening in this device it becomes more and more mysterious.Force is force. Magnetic or otherwise.
No difference between using a magnet to push something than poking it along with a stick.
The motivation behind such a device is quite mysterious...Once you start looking deeply into what is happening in this device it becomes more and more mysterious.
the only time ive seen any reference to yours is via the variable resistor to control power output@gaz1, I'm not asking for improvements to the design. Rather I am hoping for suggestions as to how the inductive drag on the disc relates to the power output of the system. We can optimise the design later, if it proves interesting but for now the design is simply for the purpose of demonstrating what I'm talking about.
I agree with you completely, @hotponyshoes, but you've missing the point. The input (rotating the disc) is not driving the output, it is merely flux switching. The movement of the magnets is what is doing the pushing and Mr Newton would have no problem with that part. Where we have to go beyond Newton's mechanics is looking at the disc and it's magnets. The input is, as far as I can tell, completely decoupled from the output - we are using one system to cause unbalance in another system. It isn't a simple case of force B = force A - friction.If you poke with a stick that has a spring on the end you push energy into the spring.
You can store that energy in the spring if you like.
Then the spring can release the same amount of energy.
There is nothing in a spring that can create extra energy on the output.
Nor in a magnet either.
but what your forgetting isI agree with you completely, @hotponyshoes, but you've missing the point. The input (rotating the disc) is not driving the output, it is merely flux switching. The movement of the magnets is what is doing the pushing and Mr Newton would have no problem with that part. Where we have to go beyond Newton's mechanics is looking at the disc and it's magnets. The input is, as far as I can tell, completely decoupled from the output - we are using one system to cause unbalance in another system. It isn't a simple case of force B = force A - friction.
Best response yet, @voipio. That's proper engineering, actually experimenting rather than just thinking you already know. Yes, the repulsion disappears and both magnets are attracted to the sheet. Certainly there will be drag as the finger passes through the magnetic field (and the finger will also be attracted into the field and resist being pulled out of the field, which should balance or cancel each other). That effect you observed will also cause the magnets to move in and out, will it not? The $64 question is, will the movement of the magnets produce as much energy as it takes to turn the rotor? "Second law of thermodynamics" is not a sufficient answer. I'd like to know how the two sides of the device are calculated (how much drag on the left and how much power on the right).Having just tested a configuration, comprising two magnets with the same poling as the original post i.e. the large flat faces are the north and south poles of each magnet, with like poles facing each other, I can concur that placing a relatively large steel sheet (wall scraper) between the two magnets does indeed largely abolish the repulsion experienced between the two magnets, though it never becomes a perceptible attraction, as such. If the steel sheet is not laterally positioned at the mid point between the magnets, it experiences an attraction to the nearest magnetic pole that becomes quite strong with decreasing distance to the magnet, and repulsion between the magnets is again present, albeit less than that which occurs without the steel sheet present. I get the strong sense that some sort of "cogging" is occuring, as described in a previous post, but the system will require a precisely made and rigid fixture, with force measurement capabilities, to actually quantify the forces that occur.
Nothing is happening in this device, you haven't made it yet.. Once you start looking deeply into what is happening in this device it becomes more and more mysterious.
Magnets, gravity, levers and almost anything else you want to pick, Newton is involved. You are not going beyond Newtonian mechanics.I agree with you completely, @hotponyshoes, but you've missing the point. The input (rotating the disc) is not driving the output, it is merely flux switching. The movement of the magnets is what is doing the pushing and Mr Newton would have no problem with that part. Where we have to go beyond Newton's mechanics is looking at the disc and it's magnets. The input is, as far as I can tell, completely decoupled from the output - we are using one system to cause unbalance in another system. It isn't a simple case of force B = force A - friction.
Sorry it's such a rough sketch. I should have moved the slots towards the centre of the cylinder a bit more so it doesn't look like the levers will go past the top and bottom of the cylinder. The slots should be entirely within the length of the cylinder. You can make such a cylinder easily by finding two tubes where one fits inside the other. Then make two 45 degree cuts in the outer tube, one at each end (but short of the end) and so that they are at 90 degrees to each other. Then slide those sections onto the inner tube, leaving a gap between the sections.There is a thing called stiction , I very much doubt if anything would start to turn on the swash rotor unless it had a helping hand. I also believe the magnetic field will diminish as the stroke increases to a point it wont return, a flywheel on the swash rotor may overcome that..
Bob
Newton wrote about classical mechanics and died before magnetism was really studied (Maxwell wasn't born until after 1800 after Newton was six foot down). So Newton isn't the guy to back you in this argument. You'll need to look beyond Newton to understand this device.Magnets, gravity, levers and almost anything else you want to pick, Newton is involved. You are not going beyond Newtonian mechanics.
Yes, you are exactly right, the slot length will need to be matched to the distance the magnets move (or close to it for best efficiency).As far as I can see from the drawing, half the length of each groove on the cylinder would have to be exactly equal to the travel experienced by the magnets to produce any actual rotation.
The magnet movement during the attraction phase would/should produce half a revolution, and the repulsion phase should complete the other half.
I suspect you’d need either a tiny cylinder or colossal magnets as I don’t think there would be much magnet movement in real terms.