How to tell if the inductor is damaged
1. Open the circuit, use the multimeter to beep, and the meter sound proves that the channel is good. If there is no sound, it means that the circuit is open, or the circuit is about to be opened, it can be judged as damage;
2. Abnormal inductance is also regarded as damage;
3. Short circuit, which will lead to leakage.
Inductance coils and transformers:
Inductance coil: When there is an electric current in the wire, a magnetic field is established around it. Usually we wind the wire into a coil to enhance the magnetic field inside the coil. Inductance coils are made by wrapping wires (enamelled, yarn-packed, or bare wires) around insulating tubes (insulators, cores, or cores) one by one (wires insulated from each other). In general, an inductance coil has only one winding.
The structure of an inductor is generally composed of a skeleton, windings, shielding cover, encapsulation material, iron core, and magnetic core!
Transformer: When the current flows through the inductance coil, it not only generates induced voltage at both ends of itself, but also can generate induced voltage in the nearby coil, which is called mutual inductance. Two coils that are not connected to each other but are close to each other and have electromagnetic induction between them are generally called transformers.
The moment the current is about to pass through the inductor, the inductor will induce a voltage in the direction of the current that is just opposite to the current to be passed, but this is only a matter of moments, and then there is no such resistance!
When the current passing through the inductor in the circuit is about to be disconnected, the inductor generates another voltage, and the current generated is just in the opposite direction of the current to be disconnected - it does not let the current be disconnected!
It can be seen that the role of an inductor is to block the change of current, but this effect is different from that of a resistor that blocks the flow of current.
Resistance hinders the current by consuming electrical energy, while inductance hinders the process of changing the current and does not consume electrical energy, when the hindrance current increases, it temporarily stores the energy of the electricity in the form of a magnetic field, and when the current decreases, it releases the energy of the magnetic field.
People use this characteristic of the inductor to "isolate AC and pass DC": when the direction of AC power is constantly changing, the inductor will continue to resist, and the result is that the AC power that changes direction cannot pass through the inductor; Direct current, on the other hand, does not change in the direction of the current, so it can pass through the inductor smoothly.
The hindrance effect of inductance on alternating current is also different: the same inductor has a large resistance to a fast-changing current, and a small resistance to a slow-changing alternating current; For alternating current with the same change speed, the inductance with a large inductance is a big obstacle, and the inductance with a small inductance is a small obstacle!
How to tell if the inductor is damaged
In addition to the above three cases of open circuit, abnormal inductance and short circuit, there are other methods that can be used to determine whether the inductor is damaged.
First, we can observe the appearance of the inductor. If the wires of the inductor coil are broken, damaged, or change in color, it may be due to damage caused by prolonged use or improper use. At the same time, if the skeleton, windings, shielding cover and other parts of the inductor are damaged or deformed, it also means that the inductor may have been damaged.
Secondly, we can preliminarily determine whether the inductor is damaged by measuring its impedance. Under normal circumstances, the impedance of the inductor should be relatively stable, if the impedance suddenly becomes larger or smaller, or if it is unstable, it may be a sign of inductor damage.
In addition, we can also test the operating current of the inductor to determine whether it is working properly. Under normal operating current, the inductor coil should be able to work normally without overheating, smoking, etc. If the operating current is abnormal, it may be due to damage to the inductor.
Finally, we can also test the performance parameters and quality of the inductor through professional electronic equipment. For example, an inductance tester can be used to measure parameters such as the amount of inductance and the figure of merit of an inductor to determine whether the inductor is working properly.
To sum up, judging whether an inductor is damaged requires a comprehensive consideration of many aspects, including appearance, impedance, operating current, and performance parameters. If the inductor is found to be abnormal, it should be treated or replaced in time to ensure the normal operation of the electronic equipment.