Hi Malcolm ! I recently published a small kindle didactic book on the electromagnetic near-field subject that is so poorly understood even by specialists. In the last part of the book I suggest that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french but it is full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
+I have seen your videos on masking. Indeed, detector behavior depends, aside its sensitivity, on the material properties (ferro and ferrimagnetic, but also para dia & anti-ferromagnetic). These effects can be shielded by other materials having the opposite properties as shown in your interesting videos.
Hi and thanks ! The Electromagnetic near-field is generally very poorly understood even by specialists. If you are interested I wrote recently a small kindle didactic book on the subject where I suggest at the end that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french but it is full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
Hi Gary, I recently published a small kindle didactic book on the electromagnetic near-field subject that is so poorly understood even by specialists. In the last part of the book I suggest that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french (it will not be a problem for you I guess) and full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
Hi Zakaria, I recently published a small kindle didactic book on the electromagnetic near-field subject that is so poorly understood even by specialists. In the last part of the book I suggest that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french but it is full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
Hi Moktaro, I recently published a small kindle didactic book on the electromagnetic near-field subject that is so poorly understood even by specialists. In the last part of the book I suggest that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french but it is full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
what is your frequency generator range? which frequency works better? you should talk about this in the video. the viewer should know what is the frequency and what frequency works better
Most conductors are not frequency dependent, the only troublesome factor is the skin effect. So the interesting question is rather: "what is the best Q-factor value one may reach for the coil and what is the corresponding frequency ?". There is no definitive answer to that question but my experience suggest that the best values are obtained for solenoids in the decimeter range with an aspect ratio close to one and a small spacing between turns (flat coils are really not good). In this case the best Q is around 1000 and the best working frequency is around 500kHz. For larger frequencies (smaller coils) the skin effect increases dramatically the resistance (even for Litz wires) and radiative losses also have a decreasing effect on Q-factor. It is well possible that carefully designed bigger solenoid (in the meter range) could lead to higher Q-factors at lower frequencies. However all this is purely theoretical, in practice the object you want to detect is surrounded by materials having a damping effect on the Q-factor of your circuit.
It is a classical serial resonant circuit but with a very high Q-factor coil (around 1000). This high-Q is obtained using a very technical winding (a special Litz wire and on a pure teflon former). The two probes are connected respectively to the input signal generator and the common contact in between the coil or the capacitor. Be careful the input voltage should be quite low if you don't want to destroy your probe and by the way a good x10 probe and a good capacitor (at least a COG type) are mandatory to maintain a high-Q for the whole resonant circuit. As explained if the Q is reduced the sensitivity/range will also be reduced.
Bonjour, est-ce que ce ne serait pas un déphasage qui se produit plutôt qu'un changement de fréquence? Et aussi j'aimerais bien savoir à quoi correspondent les deux courbes colorées sur l'oscilloscope. Dernière petite question : est-ce que votre générateur délivrait une tension sinusoidale ou un échelon? Merci d'avance !
Bonjour Bastien. En effet je me suis mal exprimé, la fréquence du générateur étant constante, c'est bien un déphasage que l'on observe (j'ai dit la fréquence va sur la droite au lieu de la courbe va sur la droite, le reste concernant les fréquences de résonnance est correct). Les deux courbes correspondent à la tension d'entrée (bleue) et la tension au point intermédiaire entre la bobine et le condensateur (jaune). Cette dernière tension est beaucoup plus grande que la tension d'entrée à cause de la résonance (Q fois plus grande pour être précis). La sonde utilisée pour la mesurer sans dégrader le Q-facteur est une sonde très particulière fabriquée par nos soins (Capacité parasite inférieure au pF et résistance dynamique supérieure au GigaOhm). Le générateur fonctionne en sinusoïdal.
@@MrBastibro Merci à vous pour votre intérêt. Juste au cas où, j'ai écrit récemment un petit livre didactique qui traite sans développements mathématiques de l'électromagnétisme en général et du champ proche en particulier: www.amazon.fr/concepts-sans-maths-L%C3%A9lectromagn%C3%A9tisme-D%C3%A9couvertes-ebook/dp/B08B427DTW/
Hi FableArchitect ! Thank you for your interest in my channel. I haven't published videos for a while but I keep some projects in mind, so stay tuned ! Here the yellow curve represents the coil voltage and the blue one is the input voltage. At resonance the two voltages are in quadrature phase and the coil voltage is about 500 time larger than the input one (Q=500). Note that a custom made probe is used on the yellow channel (1pF stray cap and GigaOhm serial resistance) to avoid probe losses and a reduction of the quality factor of the resonant circuit.
Hi FableArchitect ! Thank you for your interest in my channel. I haven't published videos for a while but I keep some projects in mind, so stay tuned ! Here the yellow curve represents the coil voltage and the blue one is the input voltage. At resonance the two voltages are in quadrature phase and the coil voltage is about 500 time larger than the input one (Q=500). Note that a custom made probe is used on the yellow channel (1pF stray cap and GigaOhm serial resistance) to avoid probe losses and a reduction of the quality factor of the resonant circuit.
The clearest explanation on the internet. Thank you.
Thanks Malcolm, I will try to add some new wireless stuff in the coming months.
Hi Malcolm ! I recently published a small kindle didactic book on the electromagnetic near-field subject that is so poorly understood even by specialists. In the last part of the book I suggest that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french but it is full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
@@kantanlabs3859 Thank you.
Traduzindo
A very good explained and illustrated video. Thanks!
+I have seen your videos on masking. Indeed, detector behavior depends, aside its sensitivity, on the material properties (ferro and ferrimagnetic, but also para dia & anti-ferromagnetic). These effects can be shielded by other materials having the opposite properties as shown in your interesting videos.
Very clear demo. Thanks.
Thank you sir
Very helpful.
Hi and thanks ! The Electromagnetic near-field is generally very poorly understood even by specialists. If you are interested I wrote recently a small kindle didactic book on the subject where I suggest at the end that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french but it is full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
Could you please post a link to a circuit diagram? Have you amplified the signal from the signal generator?
Tres bien, thank you.
Sorry for my french pronunciation and grammatical mistakes :)
Hi Gary, I recently published a small kindle didactic book on the electromagnetic near-field subject that is so poorly understood even by specialists. In the last part of the book I suggest that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french (it will not be a problem for you I guess) and full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
@@kantanlabs3859 Thanks.
Thx
Hi Zakaria, I recently published a small kindle didactic book on the electromagnetic near-field subject that is so poorly understood even by specialists. In the last part of the book I suggest that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french but it is full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
In this test, how many ohms of coil and how many microfarads of capacitors what frequency?
Beautiful
Hi Moktaro, I recently published a small kindle didactic book on the electromagnetic near-field subject that is so poorly understood even by specialists. In the last part of the book I suggest that magnetic and electric forces separate at low frequencies (low energy levels in the standard frame) and that we may rather consider 5 fundamental forces Electric, Magnetic, Weak, Strong and gravitation forces. The book is in french but it is full of illustrations easy to understand: www.amazon.com/Henri-Bondar/e/B08BK4KSN4%3Fref=dbs_a_mng_rwt_scns_share
what is your frequency generator range? which frequency works better? you should talk about this in the video. the viewer should know what is the frequency and what frequency works better
Most conductors are not frequency dependent, the only troublesome factor is the skin effect. So the interesting question is rather: "what is the best Q-factor value one may reach for the coil and what is the corresponding frequency ?". There is no definitive answer to that question but my experience suggest that the best values are obtained for solenoids in the decimeter range with an aspect ratio close to one and a small spacing between turns (flat coils are really not good). In this case the best Q is around 1000 and the best working frequency is around 500kHz. For larger frequencies (smaller coils) the skin effect increases dramatically the resistance (even for Litz wires) and radiative losses also have a decreasing effect on Q-factor. It is well possible that carefully designed bigger solenoid (in the meter range) could lead to higher Q-factors at lower frequencies. However all this is purely theoretical, in practice the object you want to detect is surrounded by materials having a damping effect on the Q-factor of your circuit.
can i have a circuit diagram or how to set up the experiment?
It is a classical serial resonant circuit but with a very high Q-factor coil (around 1000). This high-Q is obtained using a very technical winding (a special Litz wire and on a pure teflon former). The two probes are connected respectively to the input signal generator and the common contact in between the coil or the capacitor. Be careful the input voltage should be quite low if you don't want to destroy your probe and by the way a good x10 probe and a good capacitor (at least a COG type) are mandatory to maintain a high-Q for the whole resonant circuit. As explained if the Q is reduced the sensitivity/range will also be reduced.
Bonjour, est-ce que ce ne serait pas un déphasage qui se produit plutôt qu'un changement de fréquence? Et aussi j'aimerais bien savoir à quoi correspondent les deux courbes colorées sur l'oscilloscope. Dernière petite question : est-ce que votre générateur délivrait une tension sinusoidale ou un échelon? Merci d'avance !
Bonjour Bastien. En effet je me suis mal exprimé, la fréquence du générateur étant constante, c'est bien un déphasage que l'on observe (j'ai dit la fréquence va sur la droite au lieu de la courbe va sur la droite, le reste concernant les fréquences de résonnance est correct).
Les deux courbes correspondent à la tension d'entrée (bleue) et la tension au point intermédiaire entre la bobine et le condensateur (jaune). Cette dernière tension est beaucoup plus grande que la tension d'entrée à cause de la résonance (Q fois plus grande pour être précis). La sonde utilisée pour la mesurer sans dégrader le Q-facteur est une sonde très particulière fabriquée par nos soins (Capacité parasite inférieure au pF et résistance dynamique supérieure au GigaOhm). Le générateur fonctionne en sinusoïdal.
@@kantanlabs3859 Merci beaucoup!
@@MrBastibro Merci à vous pour votre intérêt. Juste au cas où, j'ai écrit récemment un petit livre didactique qui traite sans développements mathématiques de l'électromagnétisme en général et du champ proche en particulier: www.amazon.fr/concepts-sans-maths-L%C3%A9lectromagn%C3%A9tisme-D%C3%A9couvertes-ebook/dp/B08B427DTW/
what are the two waveforms on the oscilloscope? which color is what?
Hi FableArchitect ! Thank you for your interest in my channel. I haven't published videos for a while but I keep some projects in mind, so stay tuned !
Here the yellow curve represents the coil voltage and the blue one is the input voltage.
At resonance the two voltages are in quadrature phase and the coil voltage is about 500 time larger than the input one (Q=500). Note that a custom made probe is used on the yellow channel (1pF stray cap and GigaOhm serial resistance) to avoid probe losses and a reduction of the quality factor of the resonant circuit.
Hi FableArchitect ! Thank you for your interest in my channel. I haven't published videos for a while but I keep some projects in mind, so stay tuned !
Here the yellow curve represents the coil voltage and the blue one is the input voltage.
At resonance the two voltages are in quadrature phase and the coil voltage is about 500 time larger than the input one (Q=500). Note that a custom made probe is used on the yellow channel (1pF stray cap and GigaOhm serial resistance) to avoid probe losses and a reduction of the quality factor of the resonant circuit.
Must have been a plastic wedding ring.......
Frequency? You mean phase.... fail. Try again
Indeed it is the phase that is shifting not the frequency, my mistake !
The idea is that the resonance frequency is modifified but my wording in the video is truly awkward !