Excellent Bright Ring Loudspeaker Magnet w/ 5 Countsunk Holes 35H, Neo industrial loudspeaker ring magnet, Sintered Neodymium-Iron-Boron, strongest powerful horn magnets, Super Strong NdFeB Permanent Customer Speaker Magnets China Factory Excellent Bright Ring Loudspeaker Magnet w/ 5 Countsunk Holes Feature: Model Number: 35H Type: Permanent Composite: NdFeB Magnet Shape: Ring Type Application: Industrial Motor Magnet […]
The Strongest Magnet Laminated for Industrial Electronics, Neodymium Eddy Current Segment Magnet, Laminated Type Eddy Current Loss Arc Permanent Magnets, Germany Surplus Magnets China supplier factory
The Strongest Magnet Laminated for Industrial Electronics Technical requirement:
1.The thickness of insulating layers is within 0.04mm.
2. In normal temperature, the bond strength of insulating layers can reach more than 50Mpa.
3. The maximum working temperature can reach 200 ℃.
4. The whole geometric tolerance is within 0.05mm.
5. These small magnets are insulated from each other.
Eddy currents (also called Foucault’s currents) are loops of electrical current induced within conductors by a changing magnetic field in the conductor according to Faraday’s law of induction. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field.
In most cases, the eddy current loss of permanent magnets is much lower than iron loss and copper loss of the motor, but it will generate a large temperature rise in the high-speed motor and the high power density motor.
Ideally, stator magnetic field and rotor magnetic field of PMSM are rotating synchronously, or relatively static, thus permanent magnets without eddy current loss in such case. In fact, there are a series of space and time harmonics are existing in the air gap magnetic field, and these harmonic components are stemming from cogging effect, non-sinusoidal distribution of magnetomotive force and phase current. The harmonic magnetic field will link with rotor magnetic field and hence generated eddy current and caused relevant eddy current loss. It should be also noted that the harmonic magnetic field and eddy current loss will rise with increasing motor speed. Neodymium Permanent Eddy Current Magnet
In the diagram below, the conductive metal sheet (representing the moving rollercoaster car or power tool for instance), moves past a stationary magnet. As the sheet moves past the left edge of the magnet, it will feel an increase in magnetic field strength, inducing counter-clockwise eddy currents. These currents produce their own magnetic fields and according to Lenz’s Law, the direction will be upwards i.e. opposing the external magnetic field, creating magnetic drag. At the other edge of the magnet, the sheet will be leaving the magnetic field and the change of field will be in the opposite direction, thus inducing clockwise eddy currents which then produce a magnetic field acting downwards. This will attract the external magnet, also producing drag. These drag forces slow the moving sheet, providing the braking. An electromagnet can be used for the external magnet, meaning it is possible to vary the strength of the braking applied by adjusting the current through the electromagnet’s coils. An advantage of eddy braking is that it is contactless, so results in no mechanical wear. However, eddy braking is not suitable for low speed braking and because the conductor has to be moving, eddy brakes cannot hold objects in stationary positions. Thus, it is often necessary to also use a traditional friction brake.