Hi Mr.Pop, thank you for your videos. I have a question related to the magnets in general. In one of my projects I try to use a combination of an electromagnet and a permanent magnet. When the electromagnet is off , the permanent magnet is using the iron core as the attracted object. When the electromagnet is on , the permanent magnet is repelled , but only if there's no contact between them. Once there's contact , I get attraction even though in mid air they are repelling each other. Now , is this because of different attraction power between the Neodymium magnet and the electro one? Do they need to have the same pulling force or do i need more power to the electromagnet side in order to repel the neodymium magnet?. This test was run with a 3kg electromagnet (with a metallic case) and a neodymium magnet close to the diameter of the iron core.
Hi Dorin. That is an interesting question. I assume you’ve already watched my video on this topic. ( th-cam.com/video/IDYx1BjDXzE/w-d-xo.html ). I used a relatively weak magnet so if the electromagnet has the right polarity then repulsion occurs even when the permanent magnet is is contact with the iron core. (See at 2:01 in video above). However, I can imagine that a strong neodymium magnet would “overwhelm” the magnetic field of the coil and would magnetize the iron core (I.e. realign the magnetic domains) so that it produces attraction after direct contact. I can’t check this right now (still on holiday :) but I will try the experiment with a neodymium magnet if I have the time (and even post a video if I find something worth showing). Assuming that my thinking is correct, you can “fix” the problem that you are describing by using a weaker permanent magnet or by increasing the current through the electromagnet. (Obviously, I don’t know the specific circumstances of your setup so be aware that a stronger current through the coil can burn it!). Good luck with your project!
Hello again. I can confirm your observation: I repeated the experiment but this time with a strong neodymium magnet. The coil and the magnet repelled each other when there was a small gap of a couple of cm but as soon as the neodymium magnet touched the iron core it magnetized it the other way and thus created attraction (magnet remained stuck to the core) The magnetic field of the coil is much weaker than the one of the magnet even for relatively high currents. Maybe I’ll find some time in the future to record a quick video update.
Hi Mr.Pop, thank you for your videos. I have a question related to the magnets in general. In one of my projects I try to use a combination of an electromagnet and a permanent magnet. When the electromagnet is off , the permanent magnet is using the iron core as the attracted object. When the electromagnet is on , the permanent magnet is repelled , but only if there's no contact between them. Once there's contact , I get attraction even though in mid air they are repelling each other. Now , is this because of different attraction power between the Neodymium magnet and the electro one? Do they need to have the same pulling force or do i need more power to the electromagnet side in order to repel the neodymium magnet?. This test was run with a 3kg electromagnet (with a metallic case) and a neodymium magnet close to the diameter of the iron core.
Hi Dorin. That is an interesting question. I assume you’ve already watched my video on this topic. ( th-cam.com/video/IDYx1BjDXzE/w-d-xo.html ). I used a relatively weak magnet so if the electromagnet has the right polarity then repulsion occurs even when the permanent magnet is is contact with the iron core. (See at 2:01 in video above). However, I can imagine that a strong neodymium magnet would “overwhelm” the magnetic field of the coil and would magnetize the iron core (I.e. realign the magnetic domains) so that it produces attraction after direct contact. I can’t check this right now (still on holiday :) but I will try the experiment with a neodymium magnet if I have the time (and even post a video if I find something worth showing).
Assuming that my thinking is correct, you can “fix” the problem that you are describing by using a weaker permanent magnet or by increasing the current through the electromagnet. (Obviously, I don’t know the specific circumstances of your setup so be aware that a stronger current through the coil can burn it!). Good luck with your project!
Hello again. I can confirm your observation: I repeated the experiment but this time with a strong neodymium magnet. The coil and the magnet repelled each other when there was a small gap of a couple of cm but as soon as the neodymium magnet touched the iron core it magnetized it the other way and thus created attraction (magnet remained stuck to the core) The magnetic field of the coil is much weaker than the one of the magnet even for relatively high currents. Maybe I’ll find some time in the future to record a quick video update.
thnks
thanks