Understanding basic components_ inductance
2021年08月24日 already existingHuman browsing
Understanding basic components_ inductance
If you want to win the loneliest award in the electronic world I don't think it's inductance. On a circuit board, The number of inductors you can see should be equal to the number of chips supported by the stars (the basic components work for the normal operation of the chip).A wire is randomly wound several times to form an inductance, which is a magnetic related device. The sensor is represented by the letter L, and the unit is h (Henry). Of course, there are also smaller units, and its conversion relationship is 1H = 1000mh = 10000uh, 1uh = 1000nh.
Common inductance
Hollow inductor - a kind of inductor wound in the air. The induction value is very small. It is generally used in high-frequency circuits, such as the resonant frequency selection circuit of radio.
Hollow inductor
Color ring inductor - a fixed inductor manufactured by the part manufacturer. Its advantage is that the induction is fixed. It is generally used for small current filtering. The use of the inductor cannot exceed its rated current. The color ring reading reference resistance and color ring reading method, unit: uh.
Color loop inductance
Magnetic core inductor - high frequency and miniaturized products. It is hard to believe that a thumb sized ring inductor can store more than 10 watts of power (the higher the switching frequency, the more energy it can store, but the working frequency of magnetic conductive materials is limited). It is generally used for high current filter, voltage conversion and freewheeling. It is very common in the normal power supply circuit (basically 80% of the inductors are used in the power supply circuit). The leakage inductance of the ring inductor is lower than that of the I-shaped inductor, but it is difficult to wind, so it is more expensive.
Iron core inductance - large volume and weight, commonly used in low-frequency circuits and fluorescent lamps. In order to obtain more inductance (the size of the inductance is directly proportional to the number of turns of the winding and the permeability of the core), a large number of copper wires are used in the winding, so the cost is very high. Inductive ballasts are rarely used, and now they are gradually replaced by electronic ballasts..
Common mode inductance
Characteristics of inductance
When no current passes through the inductor, when the circuit is connected, it will try to prevent the current from passing through; If the sensor is without current, it will try to keep the current constant when the circuit is disconnected. To sum up, the current cannot change suddenly.
Definition of inductance
The change rate of current in the inductor depends on the voltage added at both ends, so there is a definition formula v = L * (di / DT). According to the definition formula, we can see that the voltage at both ends of the inductor is directly proportional to the current and inductance, and inversely proportional to the current change rate. If the current change rate is very high, the voltage generated will be very large, That's why we generate an arc when we turn off the sensor.
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