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Filter Inductor Main Effect

Oct 10, 2017

Filter Inductor main effect

Filter inductor is used to provide the inductance of the device, with insulated wire wound around the various coils called inductance. Its main role is to block the flow through the DC, blocking high-frequency low-frequency, that is, high-frequency signal through the inductor coil will encounter a lot of resistance, it is difficult to pass, and low-frequency signal through it when the resistance is compared Small, that is, low-frequency signal can be easier to pass through it. This makes the filter inductor with filter characteristics, the inductance coil on the DC resistance is almost zero, and the AC has a great resistance, that is, only allow DC through.

In the strict sense, the filter inductor does not consume power. Capacitive reactors are energy storage components, in the AC positive twist wave circuit, half of the time in the energy storage process, half of the time to work in the release of energy process, and its own does not consume energy. When the inductor is connected to the DC, the inductor is charged, and the charge after the two inductive charge is theoretically never disappear unless you discharge. When connected to the AC, the inductance of different charging and discharge, does not consume the power grid, but, because the inductor in the AC circuit in the non-stop charge and discharge, theoretically that the power to do the inductive power, the inductor consumes useless power.

Inductance produces a sense of resistance to the alternating current has a hindrance, will only make it less, but not energy, specifically: sense of the current changes in the current is not allowed to change the current, when the current increases when the current Increase, when the current decreases when the inductance hinders the current reduction. Inductance hinders the process of current changes does not consume electricity, hinder the current increases when it will be the energy of the magnetic field in the form of temporary storage, until the current decreases when it will release the energy of the magnetic field, as a result, is to hinder the current changes The

The basic purpose of filter inductors:

1, the role of filter inductor is mainly through the DC, blocking the exchange, in the circuit mainly play a filter, oscillation, delay, notch and so on. Inductance coil on the AC current has a hindrance, the role of the size of the sense of resistance to XL, the unit is ohm. Its relationship with the inductance L and the alternating current frequency f is XL = 2πfL, and the filter inductor can be divided into high frequency blocking coil and low frequency stray coil. Tuning and selecting the frequency: Inductor coil and capacitor in parallel can be composed of LC tuning circuit. That is, the natural oscillation frequency f0 of the circuit is equal to the frequency f of the non-AC signal, and the inductance and capacitive reactance of the loop are equal, so that the electromagnetic energy is oscillating back and forth in the inductance and capacitor. (The f = "f0" AC signal), the LC resonant circuit has the function of selecting the frequency, and can be used to determine the frequency of the circuit and the resistance of the circuit. A frequency f of the AC signal is selected.

2, filter inductors also filter signal, filter noise, stable current and suppress the role of electromagnetic interference. In electronic equipment, often see some magnetic ring, the magnetic ring and the connection cable to form a filter inductor (cable in the magnetic circle around the ring inductive coil), it is commonly used in electronic circuits anti-interference Components, high-frequency noise has a good shielding effect, it is known as the absorption of magnetic ring, usually made of ferrite material, also known as ferrite magnetic ring (referred to as magnetic ring). The magnetic ring has a different impedance at different frequencies. At low frequencies, the impedance is small, and the impedance of the magnetic ring increases sharply as the signal frequency increases.