The inductance coil is a device to work using the principle of electromagnetic induction. When a current flows through a wire, it will produce a certain magnetic field around the wire, and the electromagnetic wire and wire in the electromagnetic field within the scope of the induction effect. The wires have a role in the occurrence of the electromagnetic field itself, called the "self", namely the change of current lead their produced by changing magnetic field, the magnetic field and further affect the electric current in a wire to wire in the other; the electromagnetic range function, called "transformer".
The inductance coil and capacitor electrical properties on the contrary, "resistance of high frequency, low pass". The high frequency signal through the inductor will encounter great resistance, difficult to pass; and to present the low frequency signal by which the resistance is relatively small, low frequency signal can be easily through it. The inductance coil DC resistance to almost zero.