Inductance refers to the intensity of the current that can be induced when the coil moves in the magnetic field. The unit is Henry (H). It also refers to an element made by applying this property. Inductance is the electromagnetic induction characteristic of inductance element in the circuit! (including self inductance and mutual inductance), and the coil is an inductive element. In a broad sense, inductance exists in the circuit, and any element is not just a coil! In a circuit with sufficiently high frequency, any component line has inductance effect. Correctly speaking, the coil is an inductive element, and the main element of the inductance is the coil.
The electrical characteristics of the inductance coil are opposite to that of the capacitor, "pass through the low frequency and resist the high frequency". When the high-frequency signal passes through the inductance coil, it will encounter great resistance and it is difficult to pass through; while the resistance of the low-frequency signal when it passes through it is relatively small, that is, the low-frequency signal can easily pass through it. The resistance of the inductance coil to the direct current is almost zero.
Inductance stability of inductance coil
Stability refers to the level at which the inductance coil parameters change with the change of environmental conditions. Inductance temperature coefficient is usually used α L is used to evaluate the stability level of the coil, which indicates the stability of the inductance relative to the degree of tear. It is calculated by the following formula:
The inductance temperature coefficient is mainly caused by the geometric deformation of the coil due to the contraction of the coil conductor after heating. In order to improve the stability of the coil temperature, the coil can be manufactured by hot winding method: the wire of the winding coil is electrified, and then the coil is wound after the wire is heated. In this way, the coil can shrink after cooling and cling to the skeleton. It is no longer easy to deform after heating, and the stability is improved accordingly.
In addition to the temperature, the temperature will also cause changes in the inductance coil parameters. For example, when the humidity increases, the dispersion capacitance and loss of the coil will increase, and the stability of the coil will decrease. In order to avoid the influence of humidity on coil parameters, moisture-proof measures are usually taken when manufacturing inductive coils, such as epoxy resin packaging or stopping impregnation.
