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The magnetic field generated by the EPM is produced by the permanent magnets not by electric currents and this is the main difference with the electromagnets. An EPM uses only a pulse of current to magnetize one of the magnet in a desired direction (turning on and off the external magnetic field of the latch).
The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet, which needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.
The electromagnet loses them when current and magnetic field are removed. An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. [17] The magnetic field disappears when the current is turned off. Electromagnets usually consist of a large number of closely spaced turns of wire that create the ...
Electric motors and generators: Some electric motors rely upon a combination of an electromagnet and a permanent magnet, and, much like loudspeakers, they convert electric energy into mechanical energy. A generator is the reverse: it converts mechanical energy into electric energy by moving a conductor through a magnetic field.
For permanent magnets this is usually only a small change, but if you have an electromagnet that consists of a wire wound round an iron core, and you bring a permanent magnet near to that core, then the magnetization of that core can change drastically (for example, if there is no current in the wire, the electromagnet would not be magnetic ...
A permanent magnet in such a field rotates so as to maintain its alignment with the external field. Magnetic torque is used to drive electric motors. In one simple motor design, a magnet is fixed to a freely rotating shaft and subjected to a magnetic field from an array of electromagnets. By continuously switching the electric current through ...
Except for permanent magnet generators, a generator produces output voltage proportional to the magnetic flux, which is the sum of flux from the magnetization of the structure and the flux proportional to the field produced by the excitation current. If there is no excitation current the flux is tiny and the armature voltage is almost nil.
A magnetic drilling machine used for drilling perpendicular on a 100 mm thick workpiece of mild steel. A magnetic drilling machine is a portable drilling machine with a magnetic base (either electromagnetic or permanent magnet).