Main characteristic parameters of inductance

Release time: 2023-07-20


2.1 inductance L

inductance L represents the inherent characteristics of the coil itself, regardless of the current size. In addition to the special inductance coil (color code inductance), the inductance is generally not specifically marked on the coil, but with a specific name.

2.2 Inductive reactance XL

Inductive coil is called inductive reactance XL, and the unit is ohm. Its relationship with inductance L and AC frequency F is XL = 2πfL

2.3 quality factor Q

quality factor Q is a physical quantity representing coil quality, and Q is the ratio of inductance XL to its equivalent resistance, I .e. Q = XL/R. The higher the Q value of the coil, the smaller the loss of the loop. The Q value of the coil is related to the DC resistance of the wire, the dielectric loss of the skeleton, the loss caused by the shield or the iron core, and the influence of the high frequency skin effect. The Q value of the coil is usually several tens to several hundreds. The use of magnetic core coils, multi-strand thick coils can improve the Q value of the coil.

2.4 distributed capacitance

The capacitance between turns and turns of coil, between coil and shielding cover, and between coil and substrate is called distributed capacitance. The existence of the distributed capacitance reduces the Q value of the coil and deteriorates the stability. Therefore, the smaller the distributed capacitance of the coil, the better. The use of segmented winding method can reduce the distributed capacitance.

2.5 allowable error: the percentage obtained by dividing the difference between the actual value and the nominal value of the inductance.

2.6 Nominal Current: refers to the current allowed to pass through the coil, usually expressed by letters A, B, C, D and E respectively. The nominal current values are 50mA, 150mA, 300mA, 700mA and 1600mA.