Principle:
Inductance is based on the principle of electromagnetic induction Air core self-adhesive coil when a current flows through a wire, the self-adhesive coil will generate a certain electromagnetic field self-adhesive coil around the wire, and the wire of the electromagnetic field itself will induce the wire within the electromagnetic field range The effect of the air core coil on the wire 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 generates the 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 the audio coil is called 'mutual inductance'.
The electrical characteristics of the inductance coil are opposite to that of the capacitor, which 'resists high frequency and passes low frequency' That is to say, the high-frequency signal will encounter great resistance when passing through the inductance coil, which 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 the inductance coil to the direct current is almost zero. The resistance, capacitance and inductance of the audio coil will present a certain resistance to the flow of the electrical signal in the circuit. This resistance is called 'impedance'. The impedance of the inductance coil to the current signal uses the self inductance of the coil. Sometimes we call it 'inductance' or 'coil' for short, and use the letter 'l'. When winding the inductance coil, the number of turns of the coil is generally called 'turns' of the coil.
