The electromagnetic induction is an electromagnetic induction element wound with an insulated wire (for example, an Enameled Wire, a sandbag wire, etc.). Belong to common components. First, the role of the inductor: through the DC resistance communication This is a simple statement, the communication signal is isolated, filtered or combined with capacitors, resistors, etc. to form a resonant circuit.
The role of tuning and frequency selective inductance: the inductor coil and the capacitor in parallel can form an LC tuning circuit. That is, the natural vibration frequency f0 of the circuit is equal to the frequency f of the non-communication signal, and the inductive reactance and capacitive reactance of the loop are also flat, so the electromagnetic energy vibrates back and forth between the inductor and the capacitor, which is the resonance phenomenon of the LC loop. In resonance, because the inductive reactance and capacitive reactance of the circuit are reversed, the total inductance of the loop is the least, and the current is the largest (refer to the communication signal of f=f0). Therefore, the LC resonant circuit has the function of selecting the frequency and can The communication signal of a certain frequency f is selected.
The role of the magnetic ring inductance: the magnetic ring and the connecting cable form an inductor (the wire in the cable is wound around the magnetic ring as an inductor), which is a commonly used anti-interference element in electronic circuits, and has good high frequency noise. The shielding effect, so it is called the absorption magnetic ring, because it is generally made of ferrite data, so it is also called ferrite magnetic ring (referred to as magnetic ring). In the figure, the upper part is a one-piece magnetic ring, and the lower part is a magnetic ring with a device clamp. Magnetic rings have different impedance characteristics at different frequencies. Generally, the impedance is small at low frequencies, and the impedance of the magnetic ring sharply increases as the signal frequency increases. It can be seen that the role of the inductor is so great.