32 Replies Latest reply on Feb 12, 2017 1:20 PM by DAB

    Magnetic Radiation

    lescolliershustoke@virginmedia.com

      Hi

           a question :>

       

      I have a solenoid and it has a certain range to it, i.e. the magnetic field does not go on fro ever for practical purposes.

       

      I can adjust the design to gain more range, I can wind more turns on the armature but this won't extend the range if the core material saturates out. I can up the voltage and hence the current, but this creates more heat that I have to dissipate, and I want to power from a battery at the end of the day. So I am trying to get the longest range I can from 10 to 14 volts.

       

       

      Does anyone have an answer on which parameter to try moving first assuming the range I have is not good enough.

       

      regards

       

       

      Les C

        • Re: Magnetic Radiation
          D_Hersey

          It is tough to get much range from a solenoid.  To double the distance ya' gotta square the power.  At some point you are looking  at a linear motor or some other soln.

          • Re: Magnetic Radiation
            dougw

            One idea is to use a lever to increase travel.

            Another idea is to use a short high current pulse to get maximum range. Once the actuator has pulled in, the holding current can be reduced.

            Maybe you could even mount a second coil behind the first coil, once the actuator is pulled in enough with the first coil, activate the second coil and deactivate the first coil. The coils can overlap if needed.

            1 of 1 people found this helpful
            • Re: Magnetic Radiation
              jw0752

              Hi Les,

               

              I got the impression from your question that you are using an open coil and that you are not talking about the travel of a plunger but rather the extent that the magnetic field extends radially from the coil. Is this so?

               

              John

              1 of 1 people found this helpful
                • Re: Magnetic Radiation
                  D_Hersey

                  Forever and ever?

                  • Re: Magnetic Radiation
                    lescolliershustoke@virginmedia.com

                    Hello yes this is the case i.e. from a coil and core how do I achieve the maximum range ?  Given I have limited power i.e. a 12V battery.

                     

                    I think, but don't know, If I pick the right core material it will help, not sure about geometric shape.

                     

                    regards

                     

                    Les C

                    1 of 1 people found this helpful
                      • Re: Magnetic Radiation
                        rachaelp

                        Hi Les,

                         

                        Could you use a boost converter to increase the voltage above the 12V available from the battery?

                         

                        Best Regards,

                         

                        Rachael

                        1 of 1 people found this helpful
                        • Re: Magnetic Radiation
                          jw0752

                          Hi Les,

                          The magnetic field lines, that are being generated by a specific amount of power (Amps times Volts), are part of a magnetic circuit that by convention comes out of the north pole and loops around to enter at the south pole of the field. As with all things in nature this path is path of least resistance. Each line of magnetic force is repelled by the adjacent lines of force while simultaneously being attracted by the opposing pole of the magnet. This is why we get the characteristic field shape of a bar magnet or a solenoid.

                           

                          Capture.JPG

                           

                          Mathematically the line of force that comes out of the center of the magnetic field extends to infinity before looping back to the other pole but as D_Hersey correctly pointed out we have some form of inverse square law to deal with with respect to the intensity of the field as we go out. This makes the extension of the strength field dependent on the length of the magnet or solenoid to some extent and also the power that we put into the generation of the field. If you are looking for some way to focus the power of your solenoid's magnetic field so that you can project the magnetic effect an extended distance with a limited power source you have a very difficult engineering problem. The nature of the magnetic field is not amenable to this type of manipulation. I do not think that the converter will be of much help. For any specific coil resistance increasing the voltage will increase the current and thus increase the strength of the field but it will also create a commensurate increase in current draw from your battery. What I mean is that there will be no magic free increase in field intensity without paying for it with additional power input.

                           

                          John

                          3 of 3 people found this helpful
                            • Re: Magnetic Radiation
                              D_Hersey

                              Bravo John!

                               

                              So often in physics, if we are dealing with a polynomial it is a second-order one.

                               

                              I saw a product called a 'magnetic lens' once.  It was a radially symmetrical piece of ferrite that was fat on one and skinny on the other.  The intention IIRC, was to put the fat end near the sensed and the skinny end by a Hall-effect sensor.  But you are right, there isn't much going on in this dimension

                              • Re: Magnetic Radiation
                                lescolliershustoke@virginmedia.com

                                Mathematically the line of force that comes out of the center of the magnetic field extends to infinity before looping back to the other pole but as D_Hersey correctly pointed out we have some form of inverse square law to deal with with respect to the intensity of the field as we go out. This makes the extension of the strength field dependent on the length of the magnet or solenoid to some extent and also the power that we put into the generation of the field. If you are looking for some way to focus the power of your solenoid's magnetic field so that you can project the magnetic effect an extended distance with a limited power source you have a very difficult engineering problem. The nature of the magnetic field is not amenable to this type of manipulation. I do not think that the converter will be of much help. For any specific coil resistance increasing the voltage will increase the current and thus increase the strength of the field but it will also create a commensurate increase in current draw from your battery. What I mean is that there will be no magic free increase in field intensity without paying for it with additional power input.

                                 

                                 

                                John you have the problem nailed correctly, what you have explained is exactly what I am trying to do.  Thanks by the way to all of the other contributors I have read them all and there are far more than I expected thank you so much.

                                1 of 1 people found this helpful
                              • Re: Magnetic Radiation
                                dougw

                                As John points out, the magnetic field can be channeled by appropriate materials.

                                In solenoids these pole pieces can for example turn a linear solenoid into a horseshoe magnet, concentrating the field between the poles. This might allow you to have a much stronger field further from a pole than you would get with a linear solenoid.

                                If you describe your geometry requirements we might be able to suggest a more appropriate solution.

                              • Re: Magnetic Radiation
                                DAB

                                Hi Don,

                                 

                                Just be aware that Planck's constant and radiation law are not correct over the range indicated in the current physics domain.

                                 

                                I am still working out details, but the idea of temperature related to photon wavelength is incorrect.

                                 

                                Yes there is a correlation, but each photon represents a specific kinetic energy based upon its mass and charge.

                                 

                                If you use Planck's radiation law, you get the wrong values for any photon outside a limited domain of 1 to 3 microns.

                                 

                                Even there, he was wrong as his experimental apparatus and sensors were providing the wrong information over the ranges of temperatures he used to create his fudge factor.

                                 

                                DAB

                                 

                                PS to all, magnetism is a field, not a radiation.  Radiation occurs via photon flow where as a field is created by the movement of electric charge.

                                  • Re: Magnetic Radiation
                                    gdstew

                                    " Radiation occurs via photon flow where as a field is created by the movement of electric charge."

                                     

                                    Which creates/generates a magnetic field, hence the term electroMAGNETIC radiation.

                                      • Re: Magnetic Radiation
                                        DAB

                                        The jury is still out if electromagnetic waves can be called radiation or just energy transfer.

                                         

                                        The emission of photons is explicitly defined as "radiation" as the mass and energy is transferred via discrete objects.

                                         

                                        Long wave RF signals tend to use molecules to transfer energy, but not necessarily mass, so I think there is some doubt about using radiation with those frequencies.

                                         

                                        Magnetic force/field is just a component of the photon vibration.  It is the mass of the photon that carries the energy.

                                         

                                        I know this view is controversial, but it better fits the data and explains why there are still unresolved issues at this level of physics.

                                         

                                        DAB

                                          • Re: Magnetic Radiation
                                            gdstew

                                            The emission of photons is explicitly defined as "radiation" as the mass and energy is transferred via discrete objects.

                                             

                                            So is the emission of protons, and neutrons. At least they do actually have mass. But they never travel at the speed of light like photons/electromagnetic waves do.

                                             

                                            "Long wave RF signals tend to use molecules to transfer energy, but not necessarily mass, so I think there is some doubt about using radiation with those frequencies."

                                             

                                            I'm sorry but OMG are you serious ? They travel through "empty" space as well as as any electromagnetic wave/particle at any frequency does. Please supply all

                                            data from any experiment that says this is not so or that molecules are required for LW RF to propagate.

                                             

                                            "Magnetic force/field is just a component of the photon vibration."

                                             

                                            Citation ? And it still "radiates" with the photon.

                                             

                                            "It is the mass of the photon that carries the energy"

                                             

                                            There is absolutely no experimental data that shows that photons have mass. NONE. That is why they are able to travel at the speed of light. No particle with mass

                                            has ever been found to do that. They can get close, but no cigar.

                                             

                                            "I know this view is controversial, but it better fits the data and explains why there are still unresolved issues at this level of physics."

                                             

                                            After well over one hundred years of data from intense scientific experimentation with electromagnetic radiation and particle radiation of all forms that says it doesn't,

                                            perhaps you could share the "data" you say this hypothesis fits.

                                              • Re: Magnetic Radiation
                                                lescolliershustoke@virginmedia.com

                                                Chaps Chaps Chaps, stick to the point I am not interested in what the hell you call it radiation, propagation, distribution, self perpetuation or any other term.

                                                 

                                                What I want to know is which parameters to adjust to extend the range of a electromagnetic device i.e. a coil with a core.

                                                 

                                                I would suggest that the permeability of the material would play a big part but none of you have suggested using a material with a higher / better permeability. Is this because I am wrong ??

                                                 

                                                 

                                                regards

                                                 

                                                 

                                                Les Collier

                                                  • Re: Magnetic Radiation
                                                    dougw

                                                    You can increase power or channel the field.

                                                    To channel the field you need to stay below material saturation.

                                                    We cannot suggest a suitable channeling solution unless we know what the target geometry is.

                                                    What field strength do you need and at what distance?

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                                                    • Re: Magnetic Radiation
                                                      jw0752

                                                      Hi Les,

                                                       

                                                      Part of the beauty and nature of the discussions on E-14 is that they don't always stay on topic precisely. Sometimes they get chaotic and sometimes members will discuss personal business half way through your discussion on hall effect sensors or whatever. Everyone here has different knowledge and expertise and a general inclination to share but they will not just perform. Be patient and tease the conversation back where you want it to be by asking questions. The more specific the question the better. This is not a typical forum and respect and civility here is treated the same as if all the participants were face to face.

                                                       

                                                      If you put highly permeable material in the center of the coil and provide one also around the outside of the coil you will keep the magnetic field that is generated in close proximity to the coil. This will also slightly increase the effect of the field on either end at the N and S poles but it may not give you the kind of distance you are hoping for. Once we have concentrated the field with the permeable material the only way to increase its strength at a point in space axial to the coil will be to increase the power.

                                                       

                                                      John

                                                      2 of 2 people found this helpful
                                                      • Re: Magnetic Radiation
                                                        michaelkellett

                                                        Les, please, draw us a picture with some dimensions.

                                                         

                                                        I think what you want to make is a sort of magnetic torch, where the solenoid coil is the torch and magnetic flux is sort of beamed out of it. If so then you need to reconcile yourself to the fact that the flux will be proportionally small 1 solenoid length away from the end of the coil. Putting cores in the coil won't help because they will saturate at quite low flux levels.

                                                        Really big magnets (the superconducting things for MRI scanners) are several feet in diameter and the stray field a few feet away is quite big - but 20 feet away not very big at all.

                                                        If you want a steady state field you'll be limited by heating problems. If you want pulses you can push the power in the pulse up quite a lot.

                                                         

                                                        But we're all just guessing here - what do you actually want to do with this thing - if we knew that we might be able to help a bit more.

                                                         

                                                        MK

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                                                        • Re: Magnetic Radiation
                                                          DAB

                                                          Hi Les,

                                                           

                                                          My apologies, but I was just trying to highlight that you get better answers to your questions when you provide clear and concise descriptions of your problem or idea.

                                                           

                                                          Calling it magnetic radiation conjured up a host of ideas in my mind as I have become very intimately involved with these relationships over the last few years.

                                                           

                                                          I know you just want a simple answer, but getting the terminology correct and a clear description of your issue enables us to better focus in on an answer that will benefit you.

                                                           

                                                          DAB

                                                          2 of 2 people found this helpful
                                                          • Re: Magnetic Radiation
                                                            gdstew

                                                            All methods to do what you want do do have already been mentioned on this thread as of at least a day ago. All options to increase the range of the solenoid

                                                            by increasing the reach of the magnetic field (in this case this is what it should really be called) will require an increase in power, it's the law. At this point since

                                                            you are the only one that knows what you are actually trying to do (although you have been asked twice now to better explain it) and all the options have been

                                                            on the table for a while, no one else can add much to the discussion about your specific case or come to any kind of reasonable conclusion as to what would

                                                            probably be the best thing to do. So at this point it's up to you to figure out which method you want to use, or provide more information on what you are trying

                                                            to do so the others that may have a better understanding of magnetics can provide further guidance.

                                                            1 of 1 people found this helpful
                                                              • Re: Magnetic Radiation
                                                                lescolliershustoke@virginmedia.com

                                                                Hello Everyone

                                                                                         can I start by thanking you all so much for your contributions I have plenty to go at.

                                                                 

                                                                I am sorry I have been a bit cagy with details My patent agent said that I must not divulge anything about the device as it may prejudice my patent application which I will make in due course. That's not for one minute inferring that you might want to copy the idea, just simply that if you did not know the content you could not have been the one to spill the beans, does that make sense, I hope so and please please do not take offence. Non intended.

                                                                 

                                                                I will come back when I done some more work and let you know how I got on. Untill  then Many thanks for the input. Sufficient to say that if I am successful we may have collectively saved a life.

                                                                 

                                                                Regards

                                                                 

                                                                 

                                                                Les Collier

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                                                            • Re: Magnetic Radiation
                                                              DAB

                                                              Hi Gary,

                                                               

                                                              If you want to discuss these issue further I suggest you send me a private message and I can go into more detail.

                                                               

                                                              Yes I do understand my ideas run contrary to everything you have been told or think you know about EM, but I have evolved a more concise theory and model that clearly identifies that there are glaring errors in the current physics behind these effects.

                                                               

                                                              DAB

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