MAGNETIC LEVITATION
Levitation
The levitation is defined as : "raising of a human body above ground without support and without material help" (the Robert). It is nearly antigravity (the mass in levitation not transfered to ground) and to assist at this phenomenon will be very disquieting, but since for demos in laboratory, we can put frogs in levitation...
http://www.hfml.kun/froglev.html
In extending the definition to heavy material objects and redefining the condition "without material help" to "no support device" (which have a mass), a magnetic field that keep in position an object in suspension above the ground without any material between the ground and any point of the object put this object in levitation.
Thus an helicopter or a ball of tennis floating on a jet of water don't "levitate", the fluid that sustains them having mass. Nothing levitate alone in our planete and probably on many others !
In brief, for to produce a levitation experience well performed, amusing to contemplate, astonishing, it come to an agreement upon the following criteria, all of same importance :- The object in levitation must appears heavy.
- The object in levitation must be totally motionless.
- The object in levitation must be noiseless.
- The surface under (earth's plan) the levitating object must be flat.
- The space above the earth's plan and around object must be empty of any device
- The levitation process must be discreet otherwise umperceptible
Magnetic levitation
The way to make levitation which is interesting for us, the well know process: the utilization of magnetic fields, precisely from permanent magnets in repulsive mode. Very simple in theory, but delicate in practice when we appreciate every criteria defined above, specifically the #4, #5 & #6.
How everybody knows, if an arrangement of permanent magnets permits to create repulsive forces, they don't permit self-stabilizing of the object in levitation (Earnshaw's theorem). To meet our criteria we must to define an adequate geometry which to comply with sustentation function and an analog servo controller for the stabilization function. The criteria #4 & #5 require to add electronic complements to these two basic functions.
How everybody knows, if an arrangement of permanent magnets permits to create repulsive forces, they don't permit self-stabilizing of the object in levitation (Earnshaw's theorem). To meet our criteria we must to define an adequate geometry which to comply with sustentation function and an analog servo controller for the stabilization function. The criteria #4 & #5 require to add electronic complements to these two basic functions.
Magnetic levitation in the way of...
In the way of... what it's can be done in the laboratories, in appearence of course. This system will put (by underneath) in stable levitation a magnetic object without sophisticated material at ambient temperature. With the addition of few volutes from cryogenic liquid, the illusion would be perfect.
The self stability isn't possible, but it is not prohibed to look for a favourable "geometry" this means a geometry witch the instability is more controllable, all geometries aren't self-stable but some are more or nearly... requiring less energy for object stability control and also how many escape axes and what kinds of trajectory evolved ? 5 geometries have been studied, numbered from #1 to #5, this last one have very different properties compared to the 4 others.
The self stability isn't possible, but it is not prohibed to look for a favourable "geometry" this means a geometry witch the instability is more controllable, all geometries aren't self-stable but some are more or nearly... requiring less energy for object stability control and also how many escape axes and what kinds of trajectory evolved ? 5 geometries have been studied, numbered from #1 to #5, this last one have very different properties compared to the 4 others.
Stabilised magnetic levitation board and base
This realization requires skill in electronic and sheet metal work. it can be little bit difficult. Difficult or not, you must get results defined by the criteria #1 to #6.
This printed circuit board is mainly a multipurpose analog board, almost "universal"..., but oriented as low power analog servo controller, completed by few functions necessary for the levitation application (all components are common and economical). Several type of levitation geometries can be controlled by one or several boards like this one. The aluminum base can be make with not much tool, the two major difficulties arise from :
1- mistake of components positioning on the pcb
2- lack of precision in carry out the aluminum base.
IMPORTANT REMARK : This realization requires alas ! some skills in all quoted fields.This printed circuit board is mainly a multipurpose analog board, almost "universal"..., but oriented as low power analog servo controller, completed by few functions necessary for the levitation application (all components are common and economical). Several type of levitation geometries can be controlled by one or several boards like this one. The aluminum base can be make with not much tool, the two major difficulties arise from :
1- mistake of components positioning on the pcb
2- lack of precision in carry out the aluminum base.
Means and experience required :
- tracing, drilling, cutting with enought accuracy (between ±½mm and ±1/10 mm) few aluminium parts of thickness between 1mm and 2 mm from a sketch and to assemble them;
- to procure locally : aluminum sheet of 1.5 mm / 2mm thick : 220x100 mm minimum, angle (alu) 13x19 mm (1/2"x3/4"), nonmagnetic screws and hardware (3 mm, 4 mm, 4-40), (brass, inox), spacers, etc;
- to procure locally electronic components (all components have been selected for the easiness to find them likewise their values have been unified as well as one can;
- to assemble electronic components on printed circuit board (good quality soldering iron 25 W, desoldering pump...).
(Partial list of typical components mounted on pcb: Components); - to proceed to electronic adjustments (ruler, calliper, compass and magnetic compass, digital multimeter, trimming tool, etc.). To have access to an oscilloscope is a "plus" not only for troubleshooting but also for a better system understanding.
To finalise the adjustments is the most funny part of this realization because it's the time "to levitate" finally...
Available elements for to help to the realization
- an empty printed circuit board, ready to receive components, with schematic diagram, components implantation drawing and part list for this application,
- base plate sketch, description and parts listing;
- assembling procedure and practical informations for adjustments;
- possibly the sensors under original version;
- special request.
Stabilized magnetic levitation board
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