|
Ae：有效磁粉芯面积（cm2）与磁芯的横截面积相等（cross section area）
le:有效磁路长度或称平均磁路长度（cm）（mean magnetic path length）
V:磁芯体积：（cm3）(core volume)
OD：磁芯外径（cm）（outside diameter of core）
ID:磁芯内径（cm）(inside diameter of core)
Ht：磁芯高度（cm）
W:磁芯最小窗口面积（cm2）
1英寸（inches）=103mil=25.4mm
|
磁导率是磁滞回线上任何点所对应的B与H的比值。
In magnetics,permeability is the ability of a material to conduct flux.The magnetitude of
the permeability at a given induction is a measure of the ease with which a core material
can be magnetized to that induction.It is defined as the ratio of the flux density Bto the
magnetizing force H.
|
µe：有效磁导率（无量纲）permeability
B:磁通量密度（高斯Gauss）flux density(Gauss)
H:磁场强度（奥斯特Oe）magnetizing(Oe)
|
每种尺寸磁粉芯的额定电感量都与其有效磁导率有关，有效磁导率仅作参考环型磁芯的电感测试是依均
匀分布的单层绕组作测试依据，以非均匀分布而少圈数的磁芯作测试会产生比预期要大的电感读数。
Neu Flux Cores的电感系数值是以1000圈时为测试依据，其中电感系数偏差通常在±8%之间。
The inductance of a wound core at a given number of turns is calculated using the
following formula
|
L=0.4πµeN2Ae*10-2/le
Ln=Al&N<2>*10-3L:电感量（µH）1H=103mH=106µH=109nH inductance(µH)
Al：额定电感量（nH/N2）nominal Inductance(nH/N2)
µe:有效磁芯截面积 effective cores section area(cm2)
Ae:有效磁路长度 mean magnetic path length(cm)
N:线圈数： number of turns
Ln:在N圈时的电感量（µH）Inductance at N turns(µH)
|
安培定律揭示了磁场强度（H）与电流、圈数和磁路长度之间的关系。
Ampere's Law relates magnetizing force(H)to current,number of turns and magnetic path
length.
|
H:磁场强度（Oersteds）magnetizing force(oersteds)
N:圈数 number of turns
I:电流（A）peak magnetizing current(amperes)
Le:磁路长度（cm） mean magnetic path length(cm)
1Oersted=0.7958A/cm
|
Q值是指电感器电抗与有效电阻的比值，它反映了该电感的质量。对于电源滤波器而言，Q值提高就意味
着截止更快，衰减比更高和谐效果更好，Q值的大小主要由电感线圈的分布电容所决定。
如果忽略分布电容引起的自谐振效果，可以用以下公式计算电感器Q值。
The Qfactor is defined as the ratio of reactance to the effective resistance for inductor
and thus indicates its quality.The Qof wound core can be calculated using the following
formula,when neglecting the effects of self-resonance caused by the distributed
capacitance resulting from the differential voltage between adjacent turns.
|
Q:品质因数 quality factor
L:电感量（H）inductance(henries)
ω:2πf(Hz)2π frequency(hertz)
Rdc:绕线直流电阻（Ω）DC winding resistance(ohms)
Rac:由于磁粉芯损耗而产生的阻抗（Ω）resistance due to core loss(ohms)
Rcd:由于绕线中介电损耗而产生的阻抗（Ω）resistance due to winding dielectric loss(ohms)
|
磁通密度的大小影响磁粉芯的损耗值和磁导率。除非另有说明，本样本中所列举的数据都是基于正弦波
形和最大磁通密度（峰值）得出的。Bpk指穿过磁粉芯横截面各部分平均磁通密度值的最大值。事实上
，通过磁粉芯内径附近的磁通密度值高，而磁粉芯外径附近的磁通密度值低。
The corresponding parameter for the induces magnetic field in an area perpendicular to the
flux density is determined by the field strength permeability of the medium in which it is
measured.
|
Bpk:最大磁通密度峰值（高斯Gauss）maximum flux density(gauss)
Erms:通过绕正弦电压有效值（Vrms）sinusoidal RMS voltage across winding(Vrms)
N:圈数 number of turns
Ae:有效磁粉芯截面积（cm2）cross section area(cm2)
f：正弦波形电压频率（Hz）frequency(hertz)
1特斯拉（T）=104高斯（）Gauss=103mT
|
磁芯损耗是磁芯材料内交替磁场引致的结果。磁芯损耗有三部分组成：磁滞损耗、剩磁损耗和涡流损耗
。在高频条件下，涡流损耗是主要损耗，而低频下磁滞损耗则是主要损耗。而各种损耗形式在总损耗中
所占的比例也会受到磁通密度的影响，受到高温热老化影响的是磁芯损耗的涡流部分。
Powder cores have low hysteres is loss,minimizing signal distoion,and low residual
loss.The total core loss at low.The core loss is calculated from the following legg's
equation.
|
Rac:由磁芯损耗产生的有效电阻（Ω）resistance due tp core loss(ohms)
μe:有效磁导率 permeability
L:电感量（H）inductance(H)
a:磁滞损耗系数 hysteresis loss coefficient
Bpk:AC磁通密度峰值（高斯Gauss）maximum flux density(gauss)
c:剩磁损耗系数 residual loss coefficient
f:频率（Hz）frequency(hertz)
e:涡流损耗系数：eddy loss coefficient
|
