Common sense and technical terms of inductor products

System Oct 12 3

Inductors mainly play the role of filtering, oscillation, delay, notch, etc. in the circuit, as well as screening signals, filtering noise, stabilizing current and suppressing electromagnetic wave interference.


According to the product characteristics of inductors, it generally includes the following common sense and terms, which you must understand.


DC resistance, DC resistance is the resistance value measured under DC. The higher the resistance, the greater the power loss. The smaller the DC resistance of various inductors for resonance, impedance matching and choke, the better.


Self resonant frequency refers to the frequency when the coil itself resonates with its own capacitance. If the resonant frequency is exceeded, the inductor will not work. The self resonant frequency of various inductors for resonance, impedance matching and choke shall be greater than the working frequency.


DC superposition characteristic refers to the inductance characteristic of superimposing DC current on micro AC current.


Allowable current / rated current. Allowable current refers to the maximum DC current that can pass through the coil without damaging the element. If the current exceeds the allowable current, too much heat will be generated and the quality cannot be guaranteed. The allowable current of the choke inductor must be greater than the maximum current when the circuit is working.


Working temperature range refers to the allowable range of ambient temperature when the inductor is working. The operating temperature range does not include naturally generated heat. The working temperature range of various inductors for resonance, impedance matching and choke must be within the working temperature range of the equipment.


Magnetic saturation, if a magnetic field is applied to magnetic substances such as ferrite, magnetic flux will be generated. The inductance of the inductor depends on the degree of the magnetic flux.


The stronger the magnetic field, the smaller the increase of magnetic flux corresponding to the magnetic field. Even if the magnetic field is enhanced, the magnetic flux will not increase. This is the phenomenon of magnetic saturation of magnetic substances.


From the point of view of the inductor, as the current through the inductor increases, the magnetic field will also increase, so there will be magnetic saturation of magnetic substances, and as a result, the inductance value will decrease.


Since the magnetic saturation characteristics of inductors depend on the type and structure of magnetic materials used by inductors, and inductors used in power supply systems pass a large current, it becomes very important whether magnetic saturation is easy to occur. In order to confirm its degree, refer to the DC superposition characteristics of inductors.