This page is about inductor knowledges.
1. Abbreviation of inductor: L (Inductance) circuit symbol
2. The international standard units of inductors are: H (Henry), mH (milliHenry), uH (MicroHenry), nH (Nahen).
3. Unit conversion of 3.3 inductor: 1H = 103mH = 106 u H = 109 n H; 1n H = 10-3u H = 10-6m H = 10-9H
4. The characteristics of inductor: DC isolation, low frequency resistance and high frequency.
5. The function of inductor: filter, notch, oscillation, magnetic energy storage, etc.
6. Classification of inductors: hollow core inductance and core inductance. Core inductance can also be called iron core inductance and copper core inductance.
7. Inductance is usually expressed by “L” plus digital, such as: L6 for inductance numbered 6. Inductance coil is made by winding insulated wires on the insulated skeleton for a certain number of cycles. DC can pass through the coil, and DC resistance is the resistance of the conductor itself, and the voltage drop is very small. When AC signal passes through the coil, the two ends of the coil will generate self-inductance electromotive force. The direction of self-inductance electromotive force is opposite to the direction of applied voltage, which hinders the passage of AC. Therefore, the characteristic of inductance is through DC resistance to AC, and the higher the frequency. The greater the coil impedance is. Inductance and capacitance can form an oscillating circuit in the circuit. Generally, inductance has direct mark method and color mark method, which is similar to resistance method. For example, brown, black, gold and gold represent 1uH (error 5%) inductance.
8. Inductance measurement: Inductance quality detection includes appearance and resistance measurement. First, the appearance of the inductor is inspected whether it is intact, magnetic defect, crack, corrosion and oxidation of metal part, whether the marking is complete and clear, whether the wiring is broken or dismantled, etc. Use multimeter to preliminarily detect the inductance, measure the direct current resistance of the coil, and compare with the original. If the detection value is significantly higher than the normal value or the pointer is not moving, it may be the inductor body circuit breaking. If the detection value is much smaller than the normal value, it can be judged that the inductor body is seriously short-circuited, and the local short-circuiting of the coil needs to be detected by a special instrument.