The difference between electromagnet and permanent magnet
Electromagnets (solenoids) is a kind of electromagnetic equipment, which transforms electric energy into magnetic energy, and then transforms magnetic energy into kinetic energy (electric energy → magnetic energy → kinetic energy). First of all, the core is wound with a conductive winding matching its power. Such a coil with current has the same magnetism as a magnet, which is also called an electromagnet. We usually make it into strip or shoe shape to make the iron core more simply magnetized. In order to make the electromagnet de energized and de magnetized immediately, we often choose soft iron or silicon steel material with faster de magnetization. Such electromagnets are magnetic when they are energized, and when they are de energized, the magnetism disappears. Electromagnet is widely used in our daily life. Because of its creation, the power of generator has been greatly advanced.
Electromagnets can be divided into DC electromagnets and communication electromagnets. If an electromagnet is distinguished according to its use, it can be divided into the following five categories:
Traction electromagnet is mainly used to pull mechanical equipment, open or close various valves to perform active control mission.
Lifting electromagnet – used as lifting equipment to lift steel ingot, steel, iron sand and other ferromagnetic materials.
Brake electromagnet – it is mainly used to brake the motor to achieve the purpose of accurate stop.
Electromagnetic system of active electrical equipment, such as electromagnetic system of electromagnetic relay and contactor, electromagnetic release of active switch, operating electromagnet, etc.
Electromagnets for other purposes, such as the electromagnetic suction cup of grinding machine and electromagnetic vibrator, etc.
Permanent magnet is a kind of permanent magnet. It can be a natural product, also called natural magnet. It can also be manufactured manually (the strongest magnet is neodymium iron boron magnet). It is a material with wide hysteresis loop, high coercive force and high remanence. Once magnetized, it can adhere to stable magnetism. Also known as permanent magnetic materials, hard magnetic materials. In the application, the permanent magnet works in the second quadrant demagnetization part of the deep magnetic saturation and magnetization magnetic return line. The permanent magnet should have as high coercive force HC, remanence BR and maximum magnetic energy product (BH) m as possible to ensure the storage of maximum magnetic energy and stable magnetic. Main flow permanent magnet: rare earth permanent magnet material (Nd2Fe14B), now the strongest magnet.
Application of electromagnet
A. Crane: it is a powerful electromagnet for industry. It can be used to lift steel plates, containers and scrap iron with high current.
C. Ammeter, voltmeter, galvanometer
D. Bells, etc.
E. Active control equipment
F. Industrial initiative control, office initiative.
G. Packaging machinery, medical equipment, food machinery, textile machinery, etc.
H. Electromagnetic relay
Application of permanent magnet
Permanent magnet is widely used in electronic, electrical, mechanical, transportation, medical and daily necessities fields.
A. Permanent magnet of loudspeaker and telephone receiver; magnetic system of magnetoelectric meter;
B. The pole of generator and permanent magnet motor;
C. Permanent magnetic devices (such as permanent magnetic suction cup of surface grinder) and magnetic suspension system and magnetic bearing used in machine manufacturing industry;
D. Magnetic separation system, magnetic ore separation, magnetic purified water system, magnetron, proton accelerator magnetic system, etc.
Differences between the electromagnet and permanent magnet
1. The pole of the electromagnet can be changed, which is determined by the positive and negative pole of the electrified solenoid and the winding direction of the coil. The permanent magnet pole is fixed N A kind of S.
2. The magnetism of electromagnet can be changed, that is to say, it is electrified and magnetic, and there is no magnetism when it is not electrified. But the permanent magnet magnetism itself has nothing to do with electricity.
3. The magnetic force of the electromagnet can be changed, which is related to the number of turns and current of the coil, as well as the magnetic material and planning structure. The magnetic force of permanent magnet is relatively stable in a peak area, it is mainly affected by the external magnetic field and high temperature, the time of deposit.