Inductance works based on the principle of electromagnetic induction. When a current flows through a wire, the self-adhesive coil will produce a certain electromagnetic field around the wire, The wire itself of the electromagnetic field will induce the wire within the range of the electromagnetic field. The effect of the air core coil on the wire itself of the air core self-adhesive coil generating the electromagnetic field is called ‘self induction’, that is, the changing current generated by the wire itself will produce a changing magnetic field air core coil, which further affects the current in the wire; The effect on other wires in the electromagnetic field range of this audio coil is called ‘mutual inductance’.
The electrical characteristics of the inductance coil are opposite to those of the capacitor, which ‘resists high frequency and connects low frequency’. That is, when the high-frequency signal passes through the inductance coil, it will encounter great resistance and is difficult to pass; The resistance of low-frequency signal passing through it is relatively small, that is, low-frequency signal can pass through it easily. The resistance of inductive coil to DC is almost zero. The resistance, capacitance and inductance of the audio coil will show a certain resistance to the flow of the electrical signal in the circuit. This resistance is called ‘impedance’. The impedance of the inductive coil to the current signal uses the self inductance of the coil. The inductive coil is sometimes referred to as’ inductance ‘or’ coil ‘, represented by the letter’ l ‘. When winding the inductive coil, The number of turns of the coil we wound is generally called the ‘number of turns’ of the coil. The above is the working principle of air core coil