The hollow self adhered coil is a device that operates with the principle of electromagnetic induction. When an electric current flows through a wire, a certain electromagnetic field is generated around it, and the wire of the electromagnetic field itself induces the action of the wire within the range of the electromagnetic field. The wires produce electromagnetic field itself the role of "self", which is called wire current changes produced by the changes of their magnetic field, the magnetic field and further affect the current in the wire; in other wire this electromagnetic field range of the role, called "transformers".
The electrical characteristics of the hollow self adhered coil are opposite to that of the capacitor, "stop high frequency, pass low frequency"". High frequency signals will experience great resistance when passing through an inductance coil, which is difficult to pass through. But the resistance to the low frequency signal passing through it is relatively small, that is, the low-frequency signal can pass through it easily. The resistance of an induction coil to direct current is almost zero.
The resistance, capacitance and inductance, for their electrical signals in the circuit flow will show some resistance, the resistance we call "impedance" inductance coil which presented to the current signal using the coil inductance. Inductance coils are sometimes referred to as "inductors" or "coils". They are represented by the letter "L". When winding an inductance coil, we usually call it the number of turns of the coil".
