What is the principle of inductive coil
Information from:internet Published on:2022-03-02
Inductance is the ratio of the magnetic flux of the conductor to the current producing the alternating magnetic flux generated in and around the conductor when the alternating current passes through the conductor. When DC current passes through the inductor, there is only a fixed magnetic line of force around it, which does not change with time; However, when AC current passes through the coil, there will be magnetic lines of force around it that change with time. According to Faraday's law of electromagnetic induction - magnetoelectricity, the changing magnetic lines of force will produce induced potential at both ends of the coil, This induced potential is equivalent to a "new power supply" ". when a closed loop is formed, the induced potential will produce induced current. According to Lenz's law, the total amount of magnetic lines of force generated by the induced current should try to prevent the change of the original magnetic lines of force. Since the change of the original magnetic lines of force comes from the change of external alternating power supply, from the objective effect, the inductive coil has the characteristic of preventing the change of current in the AC circuit. The inductive coil has the characteristics of The characteristic of inertia in mechanics is similar. It is called "self induction" in electricity. Usually, sparks will occur at the moment of opening or connecting the knife switch. This is caused by the high induced potential produced by the self induction phenomenon. In short, when the inductance coil is connected to the AC power supply, the magnetic force line inside the coil will change with the alternating current, resulting in the continuous electromagnetic induction of the coil. This electromotive force generated by the change of the current of the coil itself is called "self induced electromotive force". It can be seen that the inductance is only a parameter related to the number of turns, size, shape and medium of the coil. It is a measure of the inertia of the inductance coil and has nothing to do with the applied current.
