Explanation of the basic role of inductors

Inductance is one of the important components in electronic circuits, its role in electronic circuits is mainly manifested in the following aspects: a. Choke Inductance has the role of choke, which always inhibits the passage of alternating current in the circuit. The inductor coil is connected to the circuit when the switch is on, due to the increase in current, there will be a large inrush current flowing through the inductor coil. When the switch is on, the current in the inductor coil is maximum and then decreases gradually. When the switch is off, the current in the coil is zero, but the rate of change of the current is maximum, generating a large reverse electromotive force and causing the switching tube to generate a very strong interference pulse.

Therefore, it is necessary to disconnect the two ends of the inductor coil from the circuit to prevent the sudden change of switching current. The filter inductor absorbs the induced electromotive force energy in the grid in the electronic equipment, reduces the amplitude of the pulsating current, and plays a filtering role. In switching power supplies, inductor coils usually play the role of filtering, the single pulse power supply voltage into a smooth DC voltage. Oscillating inductor coil can also be used as a component in the oscillating circuit, its role is to convert electrical energy into magnetic energy, stored, and then released. For example, in a radio, the inductor coil acts as an oscillator. The inductor coil and variable capacitor in a radio form an adjustable oscillation circuit. For different reception frequencies, the oscillator frequency is the same as the radio frequency received through the tuned loop.

This oscillating signal is transmitted through the antenna. Since the frequency characteristic curve of the inductor coil is nonlinear, the transmitted signal is also nonlinear. This nonlinear signal is transmitted and received by the antenna and then selected by the tuning loop in the radio, leaving only the desired radio signal at the end. A tuned inductor can also be used as a tuning loop. In a radio, the function of the tuning loop is to select the weak signal received.

The tuning loop consists of a variable capacitor and an inductor coil. By adjusting the capacity of the variable capacitor or the number of turns of the inductor coil, the loop undergoes a resonance phenomenon to select the desired radio signal. Temperature compensation has a strong blocking effect on the alternating current because the resistance of the coil is very small. As a result, most of the AC flux is generated around the conductor. This creates a closed loop. Because the impedance of this closed loop is small, there is a large induced electromotive force.

As a result, when an alternating current passes through the coil, a self-induced electromotive force is generated. The presence of the self-induced electromotive force causes the otherwise alternating current to be obstructed and biased. If this self-induced electromotive force is used as a measuring element, then it can be used to measure physical quantities such as temperature, pressure, and flow.