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Exact Eigenstates and Magnetic Response of Spin-1 and Spin-2 Vectorial Bose-Einstein Conden

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Exact Eigenstates and Magnetic Response of Spin-1and Spin-2Vectorial Bose-Einstein Condensates Masato Koashi 1and Masahito Ueda 21NTT Basic Research Laboratories,3-1Morinosato Wakamiya,Atsugi,Kanagawa 243-0198,Japan 2Department of Physical Electronics,Hiroshima University,Higashi-Hiroshima 739-8527,Japan The exact eigenspectra and eigenstates of spin-1and spin-2vectorial Bose-Einstein condensates (BECs)are found,and their response to a weak magnetic ?eld is studied and compared with their mean-?eld counterparts.Whereas mean-?eld theory predicts the vanishing population of the zero magnetic-quantum-number component of a spin-1antiferromagnetic BEC,the component is found to become populated as the magnetic ?eld decreases.The spin-2BEC exhibits an even richer magnetic response due to quantum correlation between 3bosons.PACS numbers:03.75.Fi,05.30.Jp Bose-Einstein condensates (BECs)of alkali-metal atoms have internal degrees of freedom due to the hyper?ne spin of the atoms.These degrees of freedom are frozen in a magnetic trap,but an optical trap liberates them to allow BEC to be in a superposition of magnetic sublevels [1].BEC is therefore described by a vectorial rather than scalar order parameter.A new feature in this BEC system as compared to super?uid helium-three is the fact that its response to an external magnetic ?eld is dominated by electronic rather than nuclear spin,and hence the response is much stronger than that of super?uid helium-three.This opens up possibilities of manipulating the magnetism of super?uid vapors.Observation of spin domains by an MIT group [2]o?ers an excellent example of such manipulations.While the experiments reported so far achieved only the spin-1vectorial BEC,the spin-2BEC also appears feasible by using the F =2multiplet of bosons such as 23Na,87Rb,or 85Rb.The mean-?eld theory (MFT)for describing a vectorial BEC was developed independently by Ohmi and Machida [3]and by Ho [4]by generalizing the Gross-Pitaevskii equation under the restriction of gauge and spin-rotation symmetry;they also used it to predict various spin textures and topological https://www.doczj.com/doc/4e9633577.html,w et al.[5]utilized techniques developed in quantum optics [6,7]to study many-body states of spin-1BEC in the absence of external ?elds,and found that spin-exchange collisions lead to rather complicated dynamical behavior of BEC that MFT fails to capture.In this Letter,we study magnetic response of spin-1and spin-2BECs by explicitly constructing exact eigenspectra and eigenstates,and compare the results with their mean-?eld counterparts.We ?rst consider a system of spin-1bosons interacting via s-wave scattering.The second-quantized Hamiltonian of the bosons subject to a uniform magnetic ?eld B and in a con?ning potential U (r )is given by ?H 0= d r ˉh 22?Ψ?α?Ψ?β?Ψβ?Ψα+ˉc 1

2M +U +ˉc 0(N ?1)|φ|2 φ=?φ.(2)

Substituting ?Ψα=?a αφinto Eq.(1)and keeping only spin-dependent terms,we obtain

?H =c 1

Exact energy eigenstates and eigenvalues of Hamiltonian(3)can be constructed as follows.We introduce an operator ?A?≡[(?a?0)2?2?a?1?a??1]/√

[F(F+1)?2N]?pF z.(5) The number of possible states|N2,F,F z for a?xed N is obtained as the coe?cient of x N of the generating function N2,F,F z x N= N2,F(2F+1)x2N2+F=(1?x)?3,and is given by(N+1)(N+2)/2.Since this number coincides with that of linearly independent states for a system of N spin-1bosons,i.e.,N+2C2,the set{|N2,F,F z }forms a complete orthonormal basis.

The ground state is obtained by minimizing Eq.(5)with N held?xed.When c1<0,it is a ferromagnetic state in which all bosons occupy the m=1state,in agreement with the prediction of MFT.When c1>0,|N2= (N?F)/2,F,F z=F is the exact ground state for

F?1

2F+3

N?F

have omitted the coordinate delta function describing the contactness of the https://www.doczj.com/doc/4e9633577.html,ing?P4+?P2+?P0=?1and ?f

i·?f j=4?P4?3?P2?6?P0(i and j label particles),?V is rewritten as?V=ˉc0+ˉc1?f i·?f j+ˉc2?P0,whereˉc0=(3g4+4g2)/7,ˉc1=(g4?g2)/7andˉc2=(3g4?10g2+7g0)/7.

To derive the second-quantized form of the Hamiltonian,it is convenient to introduce a new operator?S+≡(?a?0)2/2??a?1?a??1+?a?2?a??2.This operator creates,if applied to the vacuum,a pair of bosons in the spin-singlet state. This pair,however,should not be regarded as a single composite boson because?S+does not satisfy the commutation relations for bosons.The operator?S+instead satis?es the SU(1,1)commutation relations if we de?ne?S?≡?S?+ and?S z≡(2?N+5)/4,namely,[?S z,?S±]=±?S±and[?S+,?S?]=?2?S z;the minus sign in the last equation is the only distinction from the usual spin commutation relations.Accordingly,the Casimir operator?S2that commutes with?S±and?S z should be de?ned as?S2≡??S+?S?+?S2z??S z.The requirement that?S2z??S z??S2must be positive semide?nite leads to the allowed combinations of eigenvalues{S(S?1),S z}for?S2and?S z such that S=(2N0+5)/4 (N0=0,1,2,...)and S z=S+N2(N2=0,1,2,...).Here we introduced new quantum numbers N2and N0,where the operator?S+raises N2by one and the relation N=2N2+N0holds.We may thus interpret N2as the number of spin-singlet‘pairs’,and N0as that of all the other bosons.Noting that the second quantized form of?P0is written as 2?S+?S?/5,the second-quantized form of the spin-dependent part of the Hamiltonian can be written as

?H=c1

?S+?S??p?F z,(8)

where c i≡ˉc i d r|φ|4.

We?rst discuss MFT with a?xed total number of bosons,and de?ne a state in which all bosons are in the same single particle state as(N!)?1/2( αζα?a?α)N|vac ,where α|ζα|2=1.Noting that ?a?α′?a?β′?aβ?aα =N(N?1)ζ?α′ζ?β′ζβζα, the energy E M of the state is written as

E M=N c1(N?1)5s2?p ?f z (9)

where ?f 2= ?f z 2+|2(ζ2ζ?1+ζ?1ζ??2)+√

Nζα}for the ground state is obtained by replacing the terms c i(N?1)in E M by c i N.)The ground state and its magnetization in MFT are obtained by minimizing E M,and our results are summarized as follows.When c2>0and c1>0,the term including c2vanishes(s2=0)for the minimized state,and the magnetization increases linearly with the magnetic?eld as F z～[gμB/c1]B.Any Zeeman sublevel can take nonzero population in this case.When c2<0and20c1+|c2|>0, the c2term contributes to F z,but it only amounts to replacing c1in the expression of F z above with c1+|c2|/20. This case is quite similar to the spin-1case,and only m=±2levels are populated.In other regions of the parameters c1and c2,the ground state is ferromagnetic.

Exact energy eigenstates and eigenvalues of Hamiltonian(8)can be obtained as follows.Because operators?S±are invariant under any rotation of the system,they commute with?F2and?F z.The energy eigenstates can thus be classi?ed according to quantum numbers N2and N0,total spin F,and magnetic quantum number F z.We thus

denote the eigenstates as|N2,N0,F,F z,λ ,whereλ=1,2,...,g N

0,F is included to label degenerate states.The

energy eigenvalue for this state is

E=c1

(N?N0)(N+N0+3)?pF z,(10)

where we used2N2+N0=N.The degeneracy g N

0,F

can be calculated from generating function[8]

N0,F g N0,F x N0y F=1?xy+x2y2

The spin correlations in these ground states are rather complicated in comparison with the spin-1case.This is because the condition ?S +?S ? =0implies that the spin correlation between any two particles must avoid the singlet-like correlation.Except for this constraint,the spin correlation may be reduced to a combination of two-and three-particle correlations.Let us de?ne the operator ?A (n )?s such that it creates n bosons in the state with total spin F =s and F z =s when applied to the vacuum.Consider a set of unnormalized states,

|n 12,n 22,n 30,n 33 =?ˉP 0(?a ?2)n 12(?A (2)?2)n 22(?A (3)?0)n 30(?A (3)?3)n 33|vac (12)

with n 12,n 22,n 30=0,1,2,...and n 33=0,1.The operator ?ˉP 0is the projection to the kernel of ?S ?,which ensures ?S +?S ? =0for these states.It is easy to see that |n 12,n 22,n 30,n 33 are energy eigenstates with N 2=0,N 0=n 12+2n 22+3n 30+3n 33,and F =F z =2n 12+2n 22+3n 33.Note that the states belonging to the same eigenvalue are

not necessarily mutually orthogonal.A further analysis [8],however,shows that these states are linearly independent,and the degeneracy coincides with g N 0,F .The set (12)thus forms a complete basis of the subspace spanned by {|N 2=0,N 0,F,F z =F,λ }.The form in (12)provides an intuitive explanation for the forbidden values of F .For example,F =0is possible only when N 0is a multiple of 3because the singlet state is formed only by three particles.(b)c 2<0—The ground state should satisfy F z =F .To determine the remaining parameters {N 0,F },we ?rst separate E into the part that depends on F and l ≡2N 0?F ,and the part that depends only on N ,namely,

E =(20c 1+|c 2|)10N (N +3),(13)

where g (F,l )=F 2+[1+c (5+2l )?p ′]F +cl (l +6),c ≡|c 2|/(20c 1+|c 2|),and p ′≡40p/(20c 1+|c 2|).When 20c 1+|c 2|<0,the ground state is obtained by maximizing g (F,l ).Suppose ?rst that N is even.Since g (F,l )is a decreasing function of l in this case,the maximum should be g (0,0)=0or g (2N,0)=2N (2N +1+5c ?p ′).The ground state is thus {N 0,F }={0,0}if 40p <5|c 2|?(2N +1)|20c 1+|c 2||,and {N 0,F }={N,2N }otherwise.When N is odd,{N 0,F }={0,0}is not allowed,and we must compare g (0,6),g (2,0),and g (2N,0).The ground state is {N 0,F }={1,2}if 40p <5|c 2|?(2N +3)|20c 1+|c 2||,and {N 0,F }={N,2N }otherwise.These results indicates that in the small parameter region of ?5|c 2|/2N <～20c 1+|c 2|<0,magnetization of the ground state jumps from 0or 2to 2N.Such a large discontinuity does not appear in MFT with a linear Zeeman potential.(However,in the presence of a quadratic Zeeman potential,such a jump occurs also in MFT [2].)

When 20c 1+|c 2|>0,the ground state is obtained by minimizing g (F,l ).The function g (x,0)for real x is minimal when x =x 0≡(p ′?5c ?1)/2.Since l =0is allowed only when F =k ′≡2N ?4k with k being nonnegative integer,it is su?cient to compare the states with {N 0,F }={k ′/2?2,k ′?4},{k ′/2,k ′?3},{k ′/2,k ′?2},{k ′/2+2,k ′?1},{k ′/2,k ′}when x 0is in the region [k ′?4,k ′].The ground state is thus {N 0,F }={k ′/2,k ′}if

max {?1?c (2k ′?1),?10c (k ′+4)}

(14)

{N 0,F }={k ′/2+2,k ′?1}if

?2+6c (k ′+7)

(15){N 0,F }={k ′/2,k ′?2}if

max {?5+c (2k ′+9),?4?2c (k ′?2)}

(16)and {N 0,F }={k ′/2,k ′?3}if

?6+2c (3k ′+7)

These results indicate how magnetization increases with the applied magnetic ?eld:When F z <～1/8c ,F z takes all integer values.In the region 1/8c <～F z <～1/4c ,F z skips the values F z =2N ?4k ?1.When 1/4c <～F z <～1/c ,F z =2N ?4k ?3are further skipped,and F z takes every other integer values.When 1/c <～F z ,F z =2N ?4k are the only allowed values,so F z increases by 4at a time.

The reduced form of the states mentioned above is also helpful to illustrate this behavior.The states with

F =k ′?4,k ′?3,k ′?2,k ′?1,k ′can be written as (?A (2)?0)k +1(?a ?2)k ′/2?2|vac ,(?A (2)?0)k (?a ?2)k ′/2?3?A (3)?3|vac ,(?A (2)?0

)k (?a ?2)k ′/2?2?A (2)?2|vac ,(?A (2)?0)k ?1(?a ?2)k ′/2?3?A (2)?2?A (3)?3|vac ,(?A (2)?0)k (?a ?2)k ′/2|vac ,respectively.As the energy 4

cost required to break a singlet pair increases,transitions accompanied by this breakage requires a stronger ?eld and are eventually suppressed.

As in the spin-1case,the exact ground state shows nonzero population in the m =0,±1levels.Since the expressions of the exact results for these populations are lengthy,we only show the leading terms under the condition 1?n 12?N 2.Surprisingly,the populations are considerably di?erent for the types of possible ground states,

namely,(?A (2)?0)N 2(?a ?2)n 12(?A (2)?2)n 22(?A (3)?3)n 33|vac with n 22=0,1and n 33=0,1.The results are ?a ?1?a 1 ～ ?a ??1?a ?1 ～N 2(1+n 33)/n 12and ?a ?0?a 0 ～N 2(1+2n 22)/n 12.These results indicate that the populations in the m =0,±1states

are very sensitive to the combination of the spin correlations,and a very small di?erence in magnetization leads to large changes in the populations,by a factor of 2or 3.The origin of this drastic change is the bosonic enhancement

caused by the term (?a ?2)2?a ??1in ?A (3)?3and the term ?a ?2?a ?0in ?A (2)?2.

To summarize,we examined magnetic response of spin-1and spin-2BECs by deriving exact eigenstates of each Hamiltonian with spin-dependent interaction.The response is stepwise and the spin-1BEC shows the step of 2units re?ecting formation or destruction of singlet-like pairs.In the spin-2case,the spin correlations among 3particles appear,leading to various step sizes ranging from 1to 4units.In a small parameter region,magnetization jumps from almost zero to the maximum of the order of N .Some Zeeman-level populations,which are predicted to be zero in MFT,are found to be nonzero when the magnetic ?eld is small.These populations decrease rapidly with the increasing magnetic ?eld,which can be understood as a consequence of bosonic enhancement.The bosonic enhancement also serves as an ‘ampli?er’of a small change in spin correlations because it leads to large oscillations of Zeeman-level populations in the spin-2BEC.

This work was supported by the Core Research for Evolutional Science and Technology (CREST)of the Japan Science and Technology Corporation (JST).

电源磁芯尺寸功率参数.doc

电源磁芯尺寸功率参数

常用电源磁芯参数 MnZn 功率铁氧体 EPC 功率磁芯特点：具有热阻小、衰耗小、功率大、工作频率宽、重量轻、结构合理、易表面贴装、屏蔽效果好等优点，但散热性能稍差。用途：广泛应用于体积小而功率大且有屏蔽和电磁兼容要求的变压器，如精密仪器、程控交换机模块电源、导航设备等。 EPC型功率磁芯尺寸规格磁芯型号Type 尺寸Dimensions(mm) A B C D Emin F G Hmin EPC10/8 10.20±0.20 4.05±0.30 3.40±0.20 5.00±0.20 7.60 2.65±0.20 1.90±0.20 5.30 EPC13/13 13.30±0.30 6.60±0.30 4.60±0.20 5.60±0.20 10.50 4.50±0.30 2.05±0.20 8.30 EPC17/17 17.60±0.50 8.55±0.30 6.00±0.30 7.70±0.30 14.30 6.05±0.30 2.80±0.20 11.50 EPC19/20 19.60±0.50 9.75±0.30 6.00±0.30 8.50±0.30 15.80 7.25±0.30 2.50±0.20 13.10 EPC25/25 25.10±0.50 12.50±0.30 8.00±0.30 11.50±0.30 20.65 9.00±0.30 4.00±0.20 17.00 EPC27/32 27.10±0.50 16.00±0.30 8.00±0.30 13.00±0.30 21.60 12.00±0.30 4.00±0.20 18.50 EPC30/35 30.10±0.50 17.50±0.30 8.00±0.30 15.00±0.30 23.60 13.00±0.30 4.00±0.20 19.50 EPC39/39 39.00±0.50 19.60±0.30 15.60±0.30 18.00±0.30 30.70 14.00±0.30 10.00±0.30 24.50 EPC42/44 42.40±1.00 22.00±0.30 15.00±0.40 17.00±0.30 33.50 16.00±0.30 7.40±0.30 26.50

各种开关电源变压器各种高频变压器参数EEEEEEEIEI等等的参数

功率铁氧体磁芯常用功率铁氧体材料牌号技术参数 EI型磁芯规格及参数

PQ型磁芯规格及参数 EE型磁芯规格及参数 EC、EER型磁芯规格及参数

1,磁芯向有效截面积：Ae 2,磁芯向有效磁路长度：le 3,相对幅值磁导率：μa 4,饱和磁通密度：Bs 1磁芯损耗：正弦波与矩形波比较一般情况下，磁芯损耗曲线是按正弦波+/-交流(AC)激励绘制的，在标准的和正常的时候，是不提供极大值曲线的。涉及到开关电源电路设计的一个共同问题是正弦波和矩形波激励的磁芯损耗的关系。对于高电阻率的磁性材料如类似铁氧体，正弦波和矩形波产生的损耗几乎是相等的，但矩形波的损耗稍微小一些。材料中存在高的涡流损耗（如大一般情况下，具有矩形波的磁芯损耗比具有正弦波的磁芯损耗低一些。但在元件存在铜损的情况下，这是不正确的。在变压器中，用矩形波激励时的铜损远远大于用正弦波激励时的铜损。高频元件的损耗在铜损方面显得更多，集肤效应损耗比矩形波激励磁芯的损耗给人们的印象更深刻。举个例子，在 20kHz、用17#美国线规导线的绕组时，矩形波激励的磁芯损耗几乎是正弦波激

励磁芯损耗的两倍。例如，对于许多开关电源来说，具有矩形波激励磁芯的 5V、20A和30A输出的电源，必须采用多股绞线或利兹(Litz)线绕制线圈，不能使用粗的单股导线。 2Q值曲线所有磁性材料制造厂商公布的Q值曲线都是低损耗滤波器用材料的典型曲线。这些测试参数通常是用置于磁芯上的最适用的绕组完成的。对于罐形磁芯，Q值曲线指出了用作生成曲线时的绕组匝数和导线尺寸，导线是常用的利兹线，并且绕满在线圈骨架上。对于钼坡莫合金磁粉芯同样是正确的。用最适合的绕组，并且导线绕满了磁芯窗口时测试，则Q值曲线是标准的。Q值曲线是在典型值为5高斯或更低的低交流(AC)激励电平下测量得出的。由于在磁通密度越高时磁芯的损耗越大，故人们警告，在滤波电感器工作在高磁通密度时，磁芯的Q值是较低的。3电感量、AL系数和磁导率在正常情况下，磁芯制造厂商会发布电感器和滤波器磁芯的AL系数、电感量和磁导率等参数。这些AL的极限值建立在初始磁导率范围或者低磁通密度的基础上。对于测试AL系数，这是很重要的，测试AL系数是在低磁通密度下实施的。某些质量管理引入检验部门，希望由他们用几匝绕组检查磁芯，并用不能控制频率或激励电压的数字电桥测试磁芯。几乎毫不例外，以几百高斯、若干

磁芯参数参看

z变压器基础知识 1、变压器组成：原边（初级primary side ）绕组副边绕组（次级secondary side ）原边电感（励磁电感）‐‐magnetizing inductance 漏感‐‐‐leakage inductance 副边开路或者短路测量原边电感分别得励磁电感和漏感匝数比：K=Np/Ns=V1/V2 2、变压器的构成以及作用： 1）电气隔离 2）储能 3）变压 4）变流 ●高频变压器设计程序： 1.磁芯材料 2.磁芯结构 3.磁芯参数 4.线圈参数 5.组装结构 6.温升校核 1.磁芯材料软磁铁氧体由于自身的特点在开关电源中应用很广泛。其优点是电阻率高、交流涡流损耗小，价格便宜，易加工成各种形状的磁芯。缺点是工作磁通密度低，磁导率不高，磁致伸缩大，对温度变化比较敏感。选择哪一类软磁铁氧体材料更能全面满足高频变压器的设计要求，进行认真考虑，才可以使设计出来的变压器达到比较理想的性能价格比。 2.磁芯结构选择磁芯结构时考虑的因数有：降低漏磁和漏感，增加线圈散热面积，有利于屏蔽，线圈绕线容易，装配接线方便等。漏磁和漏感与磁芯结构有直接关系。如果磁芯不需要气隙，则尽可能采用封闭的环形和方框型结构磁芯。 3.磁芯参数：磁芯参数设计中，要特别注意工作磁通密度不只是受磁化曲线限制，还要受损耗的限制，同时还与功率传送的工作方式有关。磁通单方向变化时：ΔB=Bs‐Br，既受饱和磁通密度限制，又更主要是受损耗限制，（损耗引起温升，温升又会影响磁通密度）。工作磁通密度Bm=0.6～0.7ΔB 开气隙可以降低Br,以增大磁通密度变化值ΔB，开气隙后，励磁电流有所增加，但是可以减小磁芯体积。对于磁通双向工作而言：最大的工作磁通密度Bm，ΔB=2Bm。在双方向变化工作模式时，还要注意由于各种原因造成励磁的正负变化的伏秒面积不相等，而出现直流偏磁问题。可以在磁芯中加一个小气隙，或者在电路设计时加隔直流电容。 4.线圈参数：线圈参数包括：匝数，导线截面（直径），导线形式，绕组排列和绝缘安排。导线截面（直径）决定于绕组的电流密度。通常取J为2.5～4A/mm2。导线直径的选择还要考虑趋肤效应。如必要，还要经过变压器温升校核后进行必要的调整。 4.线圈参数：一般用的绕组排列方式：原绕组靠近磁芯，副绕组反馈绕组逐渐向外排列。下面推荐两种绕组排列形式： 1）如果原绕组电压高（例如220V），副绕组电压低，可以采用副绕组靠近磁芯，接着绕反馈绕组，原绕组在最外层的绕组排列形式，这样有利于原绕组对磁芯的绝缘安排； 2）如果要增加原副绕组之间的耦合，可以采用一半原绕组靠近磁芯，接着绕反馈绕组和副绕组，最外层再绕一半原绕组的排列形式，这样有利于减小漏感。 5.组装结构：

单端反激式开关电源磁芯尺寸和类型的选择

单端反激式开关电源磁芯尺寸和类型的选择字体大小：大|中|小2008-08-28 12:53 - 阅读：1655 - 评论：1 单端反激式开关电源磁芯尺寸和类型的选择徐丽红王佰营wbymcs51.blog.bokee .net A、InternationalRectifier 公司--56KHz 输出功率推荐磁芯型号 0---10WEFD15 SEF16 EF16 EPC17 EE19 EF(D)20 EPC25 EF(D)25 10-20WEE19 EPC19 EF(D)20 EE,EI22 EF(D)25 EPC25 20-30WEI25 EF(D)25

EPC25 EPC30 EF(D)30 ETD29 EER28(L) 30-50WEI28 EER28(L) ETD29 EF(D)30 EER35 50-70WEER28L ETD34 EER35 ETD39 70-100WETD34 EER35 ETD39 EER40 E21 摘自 InternationalRectifier,AN1018- “应用 IRIS40xx 系列单片集成开关 IC 开关电源的反激式变压器设计” B、ELYTON公司https://www.doczj.com/doc/4e9633577.html, 型号输出功率（ W） <5 5-10 10-20 20-50 50-100 100-200 200-500 500-1K

EI EI12.5 EI16 EI19 EI25 EI40 -- EI50 EI60 EE EE13 EE16 EE19 EE25 EE40 EE42 EE55 EE65 EF EF12.6 EF16 EF20 EF25 EF30 EF32 EFD -- EFD12 EFD15 EFD20 EFD25 EFD30 EPC -- EPC13 EPC17 EPC19 EPC25 EPC30 EER EER9.5 EER11 EER14.5 EER28 EER35 EER42 EER49 -- ETD ETD29 ETD34 ETD44 ETD49 ETD54 -- EP EP10 EP13 EP17 EP20 -- RM RM4 RM5 RM6 RM10 RM12 POT POT1107 POT1408 POT1811 POT2213POT3019 POT3622 POT4229 -- PQ -- -- -- PQ2016 PQ2625 PQ3230 PQ3535 PQ4040 EC ---------------------------- -- EC35 EC41 EC70 摘自 PowerTransformers OFF-LINE Switch Mode APPLICATION NOTES

磁芯参数表

常用磁芯参数表【EER磁芯】 ■ 用途：高频开关电源变压器、匹配变压器、扼流变压器等。【EE磁芯】 ■ 用途：电源转换用变压器及扼流圈、通讯及其他电子设备变压器、滤波器、电感器及扼流圈、脉冲变压器等。

【ETD磁芯】 ■ 用途：电源转换用变压器及扼流圈、通讯及其他电子设备变压器、滤波器。【EI 磁芯】 ■ 用途：高频开关电源变压器、功率变压器、整流变压器、电压互感器等。【ET 磁芯】 ■ 用途：滤波变压器【EFD 磁芯】 ■ 用途：高频开关电源变压器器、整流变压器、开关变压器等。

【UF 磁芯】 ■ 用途：整流变压器、脉冲变压器、扼流变压器、电源变压器等。【PQ 磁芯】 ■ 用途高频开关电源变压器、整流变压器等。【RM 磁芯】 ■ 用途：高频开关电源变压器、整流变压器、屏蔽变压器、脉冲变压器、脉冲功率变压器、扼流变压器、滤波变压器。【EP 磁芯】 ■ 用途：功率变压器、宽频变压器、屏蔽变压器、脉冲变压器等。

【H 磁芯】 ■ 用途：宽带变压器、脉冲变压器、脉冲功率变压器、隔离变压器、滤波变压器、扼流变压器、匹配变压器等。软磁铁氧体磁芯形状与尺寸标准(一) 软磁铁氧体磁芯形状软磁铁氧体是软磁铁氧体材料和软磁铁氧体磁芯的总称。软磁铁氧体磁芯是用软磁铁氧体材料制成的元件或零件，或是由软磁铁氧体材料根据不同形式组成的磁路。磁芯的形状基本上由成型（形）模具决定，而成型（形）模具又根据磁芯的形状进行设计与制造。磁芯按磁力线的路径大致可分两大类；磁芯按具体形状分，有各种各样：磁芯按磁力线路径分类磁芯按使用时磁化过程所产生磁力线的路径可分为开路磁芯和闭路磁芯两类。第一类为开路磁芯。这类磁芯的磁路是开启的（open magnetic circuits），通过磁芯的磁通同时要通过周围空间（气隙）才能形成闭合磁路。开路磁芯的气隙占磁路总长度的相当部分，磁阻很大，磁路中的部分磁通在达到气隙以前就已离开磁芯形成漏磁通。因而，开路磁芯在磁路各个截面上的磁通不相等，这是开路磁芯的特点。由于开路磁芯存在大的气隙，磁路受到退磁场作用，使磁芯的有效磁导率μe比材料的磁导率μi有所降低，降低的程度决定于磁芯的几何形状及尺寸。开路磁芯有棒形、螺纹形、管形、片形、轴向引线磁芯等等。IEC 1332《软磁铁氧体材料分类》标准中称开路磁芯为OP类磁芯。第二类磁芯为闭路磁芯。这类磁芯的磁路是闭合的（closed magnetic circuits），或基本上是闭合的。IEC 1332称闭路磁芯为CL类磁芯。磁路完全闭合的磁芯最典型的是环形磁芯。此外，还有双孔磁芯、多孔磁芯等等。

开关电源参数计算

（1）输入电压：185V AC~240V AC （2）输出电压1：+5VDC ，额定电流1A ，最小电流750mA ；（3）输出电压2：+12VDC ，额定电流1A ，最小电流100mA ；（4）输出电压3：-12VDC ，额定电流1A ，最小电流100mA ；（5）输出电压4：+24VDC ，额定电流1.5A ，最小电流250mA ；（6）输出电压纹波：+5V ，±12V ：最大100mV （峰峰值）；+24V ：最大250mV （峰峰值）（7）输出精度：+5V ，±12V ：最大± 5%；+24V ：最大± 10%；（8）效率：大于80% 3. 参数计算（1）输出功率： 5V 112V 1224V 1.565 out P A A A W =?+??+?= （3-1）（2）输入功率： 6581.2580%0.8 out in P W P W = == （3-2）（3）直流输入电压：采用单相桥式不可控整流电路 (max)240VAC 1.414=340VDC in V =? （3-3） (min)185VAC 1.414=262VDC in V =? （3-4）（4）最大平均电流： (m a x ) (m i n )81.25 0.31262in in in P W I A V V == = （3-5）（5）最小平均电流： (min)(max) 81.250.24340 in in in P W I A V = = = （3-6）（6）峰值电流：可以采用下面两种方法计算，本文采用式（3-8）的方法。

(min)max (min)(min)225581.25 1.550.4262out out out Pk C in in in P P P W I I A V D V V V ?== ====? （3-7） min 5.5 5.581.25 1.71262out Pk C in P W I I A V V ?== == （3-8）（7）散热：基于MOSFET 的反激式开关电源的经验方法：损耗的35%是由MOSFET 产生，60%是由整流部分产生的。开关电源的损耗为： (180%)81.25 20%16.25D in P P W W =?-=?= （3-9） MOSFET 损耗为： 35%16.2535% 5.69D MOSFET D P P W W -=?=?= （3-10）整流部分损耗： (5)55( )60%()16.2560%0.756565D V D W W P P W W W W +=??=??= （3-11） (12)12122()60%2()16.2560% 3.66565D V D W W P P W W W W ±=???=???= （3-12） (242)3636()60%()16.2560% 5.46565D V D W W P P W W W W +=??=??= （3-13）（8）变压器磁芯：采用天通的EER40/45，饱和磁通密度Bs 在25℃时大于500mT ，在100℃时大于390mT 。窗口有效截面积Ae=152.42mm 2。所以，取 max 11 0.390.222 s B B T T = =?≈ （3-14） Ae=152.42mm 2 （3-15）（9）开关电源频率： 40f khz = （3-16）（10）开关电源最大占空比： max 0.4D = （3-17）

磁芯各参数详解

一、磁芯初始磁导率磁感应强度与磁场强度的比值称为磁导率。初始磁导率高：相同圈数感值大，反之亦然；初始磁导率高：相同电流下容易饱和，反之亦然；初始磁导率高：低频特性好，高频差，反之亦然；初始磁导率高：相同产品价格高，反之亦然； 1、磁导率的测试仪器功能磁导率的测量是间接测量，测出磁心上绕组线圈的电感量，再用公式计算出磁心材料的磁导率。所以，磁导率的测试仪器就是电感测试仪。在此强调指出，有些简易的电感测试仪器，测试频率不能调，而且测试电压也不能调。例如某些电桥，测试频率为100Hz 或1kHz，测试电压为0.3V，给出的这个0.3V并不是电感线圈两端的电压，而是信号发生器产生的电压。至于被测线圈两端的电压是个未知数。如果用高档的仪器测量电感，例如Agilent 4284A精密LCR测试仪，不但测试频率可调，而且被测电感线圈两端的电压及磁化电流都是可调的。了解测试仪器的这些功能，对磁导率的正确测量是大有帮助的。 2、材料磁导率的测量方法和原理说起磁导率μ的测量，似乎非常简单，在材料样环上随便绕几匝线圈，测其电感，

找个公式一算就完了。其实不然，对同一只样环，用不同仪器，绕不同匝数，加不同电压或者用不同频率都可能测出差别甚远的磁导率来。造成测试结果差别极大的原因，并非每个测试人员都有精力搞得清楚。本文主要讨论测试匝数及计算公式不同对磁导率测量的影响。 2.1 计算公式的影响大家知道，测量磁导率μ的方法一般是在样环上绕N匝线圈测其电感L，因为可推得L的表达式为： L=μ0 μN 2A/l （1）所以，由（1）式导出磁导率的计算公式为： μ=Ll/μ0N 2A（2）式中：l为磁心的磁路长度，A为磁心的横截面积。对于具有矩形截面的环型磁芯，如果把它的平均磁路长度l=π（D+d）/2就当作磁心的磁路长度l，把截面积A=h（D-d）/2，μ0=4π×10-7都代入（2）式得二、饱和磁通密度 1.什么是磁通：磁场中垂直通过某一截面的磁感应线总数，称为磁通量（简称磁通） 2.什么是磁通密度：单位面积垂直通过的磁感应线的总数（磁通量）称为磁通密度，磁通密度即磁感应强度。

电源磁芯尺寸功率参数

EPC功率磁芯电气特性及有效参数

注：AL值测试条件为1KHz,0.25v,100Ts,25±3℃ Pc值测试条件为100KHz,200mT,100℃ EE、EEL、EF型功率磁芯

特点：引线空间大，绕制接线方便。适用围广、工作频率高、工作电压围宽、输出功率大、热稳定性能好用途：广泛应用于程控交换机电源、液晶显示屏电源、大功率UPS逆变器电源、计算机电源、节能灯等领域。 EE、EEL、EF型功率磁芯尺寸规格 Dimensions(mm)尺寸磁芯型号TYP A B C D Emin F EE5/5.3/2 5.25±0.15 2.65±0.15 1.95±0.15 1.35±0.15 3.80 2.00±0.15 EE8.3/8.2/3.6 8.30±0.30 4.00±0.25 3.60±0.20 1.85±0.20 6.00 3.00±0.15 EE10/11/4.8 10.20±0.30 5.60±0.30 4.80±0.25 2.50±0.257.50 4.40±0.30 EE12.8/15/3.6 12.70±0.307.40±0.30 3.60±0.25 3.60±0.258.60 5.50±0.30 EE13/12/6 13.20±0.30 6.10±0.30 5.90±0.30 2.70±0.309.80 4.70±0.30 EE13/13W 13.00±0.40 6.50±0.30 9.80±0.30 3.60±0.209.00 4.60±0.20 EE16/14/5 16.10±0.407.10±0.30 4.80±0.30 4.00±0.3011.70 5.20±0.20 EE16/14W 16.10±0.407.25±0.30 6.80±0.30 3.20±0.3512.50 5.60±0.30 EE19/16/5 19.10±0.408.00±0.30 4.85±0.30 4.85±0.3014.00 5.60±0.30 EE19/16W 19.30±0.408.30±0.307.90±0.30 4.80±0.3014.00 5.70±0.30 EE22/19/5.7 22.00±0.509.50±0.30 5.70±0.30 5.70±0.3015.60 5.70±0.30 EE25/20/6 25.40±0.5010.00±0.30 6.35±0.30 6.35±0.3018.60 6.80±0.30

开关电源磁芯主要参数

第5章开关电源磁芯主要参数 5.1 概述 5.1.1 在开关电源中磁性元件的作用这里讨论的磁性元件是指绕组和磁心。绕组可以是一个绕组，也可以是两个或多个绕组。它是储能、转换和/或隔离所必备的元件，常把它作为变压器或电感器使用。作为变压器用，其作用是：电气隔离；变比不同，达到电压升、降；大功率整流副边相移不同，有利于纹波系数减小；磁耦合传送能量；测量电压、电流。作为电感器用，其作用是：储能、平波、滤波；抑制尖峰电压或电流，保护易受电压、电流损坏的电子元件；与电容器构成谐振，产生方向交变的电压或电流。 5.1.2 掌握磁性元件对设计的重要意义磁性元件是开关变换器中必备的元件，但又不易透彻掌握其工作情况（包括磁材料特性的非线性，特性与温度、频率、气隙的依赖性和不易测量性）。在选用磁性元件时，不像电子元件可以有现成品选择。为何磁性元件绝大多数都要自行设计呢？主要是变压器和电感器涉及的参数太多，例如：电压、电流、频率、温度、能量、电感量、变比、漏电感、磁材料参数、铜损耗、铁损耗等等。磁材料参数测量困难，也增加了人们的困惑感。就以Magnetics公司生产的其中一种MPP铁心材料来说，它有10种μ值，26种尺寸，能在5种温升限额下稳定工作。这样，便有10×26×5= 1300种组合，再加上前述电压、电流等电参数不同额定值的组合，将有不计其数的规格，厂家为用户备好现货是不可能的。果真有现货供应，介绍磁元件的特性、参数、使用条件的数据会非常繁琐，也将使挑选者无从下手。因此，绝大多数磁元件要自行设计或提供参数委托设计、加工。本章将介绍磁元件的一般特性，针对使用介绍设计方法。结合线性的具体形式的设计方法，以后还将进一步的介绍。 5.1.3 磁性材料基本特性的描述磁性材料的特性首先用B-H平面上的一条磁化曲线来描述。以μ表示B/H，数学上称为斜率，表示为tanθ=B/h；电工上称为磁导率，如图5.1所示。由于整条曲线多处弯曲，因此有多个μ值称呼。另外，从不同角度考查也有不同称呼。

开关电源磁芯尺寸功率等参数

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开关电源磁芯尺寸功率等参数 MnZn 功率铁氧体 EPC功率磁芯特点：具有热阻小、衰耗小、功率大、工作频率宽、重量轻、结构合理、易表面贴装、屏蔽效果好等优点，但散热性能稍差。用途：广泛应用于体积小而功率大且有屏蔽和电磁兼容要求的变压器，如精密仪器、程控交换机模块电源、导航设备等。 EPC型功率磁芯尺寸规格磁芯型号Type 尺寸Dimensions(mm) A B C D Emin F G Hmin EPC10/8 10.20±0.20 4.05±0.30 3.40±0.20 5.00±0.20 7.60 2.65±0.20 1.90±0.20 5.30 EPC13/13 13.30±0.30 6.60±0.30 4.60±0.20 5.60±0.20 10.50 4.50±0.30 2.05±0.20 8.30 EPC17/17 17.60±0.50 8.55±0.30 6.00±0.30 7.70±0.30 14.30 6.05±0.30 2.80±0.20 11.50 EPC19/20 19.60±0.50 9.75±0.30 6.00±0.30 8.50±0.30 15.80 7.25±0.30 2.50±0.20 13.10 EPC25/25 25.10±0.50 12.50±0.30 8.00±0.30 11.50±0.30 20.65 9.00±0.30 4.00±0.20 17.00 EPC27/32 27.10±0.50 16.00±0.30 8.00±0.30 13.00±0.30 21.60 12.00±0.30 4.00±0.20 18.50 EPC30/35 30.10±0.50 17.50±0.30 8.00±0.30 15.00±0.30 23.60 13.00±0.30 4.00±0.20 19.50 EPC39/39 39.00±0.50 19.60±0.30 15.60±0.30 18.00±0.30 30.70 14.00±0.30 10.00±0.30 24.50 EPC42/44 42.40±1.00 22.00±0.30 15.00±0.40 17.00±0.30 33.50 16.00±0.30 7.40±0.30 26.50

常用铁氧体磁芯规格

常用铁氧体磁芯规格、型号与技术参数功率铁氧体磁芯 EI EE EE PQ EC EI60 EE80 EE35 PQ50/50 EC90 EI50 EE72 EE30 PQ40/40 EC70 EI40 EE70 EE25 PQ35/35 EC52 EI35 EE60 EE19 PQ32/30 ECI70 EI33 EE55 EE16 PQ32/20 EER49/54 EI30 EE50 EE13 PQ26/25 EER49/43 EI28 EE49 EE10 PQ26/20 EER49/38 EI25 EE42 — PQ20/20 EER42/43 EI22 EE42/20 — PQ20/16 EER42/45 EI19 — — — EER40/45 EI16 — — UF102 EER28L 常用功率铁氧体材料牌号技术参数项目条件单位 PC30 PC40 2500B B25 3C8 N27 μi — — 2500 2300 2500 2300 2000 2000 Bms H=1200A/m mT 510 510 490 510 450 510 Br H=800A/m mT 117 95 100 130 — — Hc — A/m 12 14.3 15.9 15.9 18.8 20 Tc — ℃ >230 >215 >230 >220 >200 >220 P 200mT23℃ 25KHz60℃ 100℃ KW/m3 130 600 95 600 900 48 KW/m3 90 — 70 — — — KW/m3 100 — 75 — — — 100mT60℃ 100KHz100℃KW/m3 — 450 — 450 — — KW/m3 — 410 — 410 — — 公司 — — TDK TDK TOKIN TOKIN FERROCXLUB E SIEMENS

磁芯规格对照表

Dimensions (mm)Ap Ae Aw A L Le Ve Wt P CL 100kHz 200mT Pt 100kHz 幅寬mm 窗口面积mm 2 PIN A * B * C ( cm 4 ) ( mm 2 )( mm 2 )(nH/N 2) ( mm ) ( mm 3 ) ( g ) @100℃(W) (W) 可配合BOBBIN EC353C8535.3*17.3*9.5 1.374184.30163.002100.077.406530.038.0021.5 8H EC413C8541.6*19.5*11.6 2.5894121.00214.002700.089.3010800.060.0024.58H EC523C8552.2*24.2*13.4 5.5980180.00311.003600.0105.0018800.0112.0028.312H EC703C8571.7*34.5*16.417.8281279.00639.003900.0144.0040100.0254.0041.412/34H EE05PC40 5.25*2.65*1.950.0013 2.63 5.00285.012.6033.10.160.02 1.1 2.76-8H EE6.3PC40 6.1*2.85*7.950.0015 3.31 4.46405.012.2040.40.240.02 2.76H EE8PC408.3*4.0*3.60.00917.0013.05590.019.47139.00.700.06 1.9 4.78 5.36H EE10/11PC4010.2*5.5*4.750.028712.1023.70850.02 6.60302.0 1.500.16 6.612.28V EE13PC4013.0*6.0*6.150.05701 7.1033.351130.030.20517.0 2.700.2357.422.210V EE16PC4016*7.2*4.80.076519.2039.851140.035.00672.0 3.300.31 8.527.36-10V H EE19PC401 9.1*7.95*5.00.124323.0054.041250.039.40900.0 4.800.42933.16-8V H EE19/16PC4019.29*8.1*4.750.119122.4053.151350.039.10882.0 4.800.41933.16-8V H EE20/20/5PC4020.15*10*5.10.119131.0050.701460.043.001340.07.500.51EE22PC4022*9.35*5.750.119141.0038.792180.039.401610.08.800.618.45208 V EE2329S PC4023*14.7*6 0.119135.80122.001250.064.902320.012.00 1.16EE25/19PC4025.4*9.46*6.290.119140.0078.202000.048.701940.09.100.99.842.5EE25.4PC4025.4*9.66*6.350.119140.3078.732000.048.701963.010.000.9EE2825PC4028*12.75*10.60.119186.9098.103300.057.705010.026.00 2.519.639.410V EE30 PC4030*13.15*10.70.1191109.0073.354690.057.706310.032.00 2.913.743.210-12V EE30/30/7PC4030.1*15*7.050.119159.70124.872100.066.904000.022.00 1.51EE3528PC4034.6*14.3*9.30.119184.80158.002600.069.705910.029.00 2.9615.788.712V EE40PC4040*17*10.70.1191127.00173.234150.077.009810.050.00 4.217.3 108 12 V EE4133PC4041.5*17*12.70.1191157.00180.004200.079.0012470.064.00 6.25EE42/21/15PC4042*21.2*150.1191178.00278.003800.097.9019510.088.008.8EE42/21/20PC4042*21.2*20 0.1191235.00275.005000.097.8023000.0116.0011.6EE47/39PC4047.12*19.63*15.620.1191242.00196.406660.090.6021930.0108.009.7EE50 PC4050*21.3*14.60.1191226.00253.736110.095.8021600.0116.009.421.317012V EE55/55/21PC4055.15*27.5*20.70.1191354.00386.347100.0123.0043700.0234.0011.0(150MT) EE57/47PC4056.57*23.6*18.80.1191344.00282.368530.0102.0035100.0190.008.5EE60PC4060*22.3*15.60.1191247.00399.025670.0110.0027100.0135.0012.523.829412V EE50.3 PC4050.3*25.6*6.10.1191120.85152.642900.0104.9012676.068.00 5.8328.2596.0512H EE62.3/62/6PC4062.3*31*6.10.1191153.01198.223100.0125.7419240.0102.008.8533.85115.0912H EE65/32/27 PC40 65.15*32.5*27 0.1191 535.00 575.00 8000.0 147.0078700.0 399.00 5.9(100MT) EC EE CORE参数对照表形狀 TYPE MATE-RIAL

单端反激式开关电源磁芯尺寸和类型的选择

单端反激式开关电源磁芯尺寸和类型的选择字体大小：大| 中| 小2008-08-28 12:53 - 阅读：6184 - 评论：2 单端反激式开关电源磁芯尺寸和类型的选择徐丽红王佰营 https://www.doczj.com/doc/4e9633577.html, A、InternationalRectifier公司--56KHz 输出功率推荐磁芯型号 0---10WEFD15 SEF16 EF16 EPC17 EE19 EF(D)20 EPC25 EF(D)25 10-20WEE19 EPC19 EF(D)20 EE,EI22 EF(D)25 EPC25 20-30WEI25 EF(D)25 EPC25

EPC30 EF(D)30 ETD29 EER28(L) 30-50WEI28 EER28(L) ETD29 EF(D)30 EER35 50-70WEER28L ETD34 EER35 ETD39 70-100WETD34 EER35 ETD39 EER40 E21 摘自InternationalRectifier,AN1018-“应用IRIS40xx系列单片集成开关IC开关电源的反激式变压器设计” B、ELYTONE公司https://www.doczj.com/doc/4e9633577.html, 型号输出功率（W） <5 5-10 10-20 20-50 50-100 100-200 200-500 500-1K EI EI12.5 EI16 EI19 EI25 EI40 EI50 EI60 --

EE EE13 EE16 EE19 EE25 EE40 EE42 EE55 EE65 EF EF12.6 EF16 EF20 EF25 EF30 EF32 -- -- EFD -- EFD12 EFD15 EFD20 EFD25 EFD30 -- -- EPC -- EPC13 EPC17 EPC19 EPC25 EPC30 -- -- EER EER9.5 EER11 EER14.5 EER28 EER35 EER42 EER49 -- ETD -- -- ETD29 ETD34 ETD44 ETD49 ETD54 -- EP EP10 EP13 EP17 EP20 -- -- -- -- RM RM4 RM5 RM6 RM10 RM12 RM14 -- -- POT POT1107 POT1408 POT1811 POT2213POT3019 POT3622 POT4229 -- PQ -- -- -- PQ2016 PQ2625 PQ3230 PQ3535 PQ4040 EC -- -- -- -- -- EC35 EC41 EC70 摘自PowerTransformers OFF-LINE Switch Mode APPLICATION NOTES "Converter circuitas a function of S.M.P.S. output voltage (Vo) and output power (Po)" C、Fairchild Semiconductor公司--67KHz Output Power EIcore EE core EPC core EER core 0-10W EI12.5 EE8 EPC10

开关电源磁芯尺寸和类型的选择(凭经验)

单端反激式开关电源磁芯尺寸和类型的选择字体大小：大| 中| 小2008-08-28 12:53 - 阅读：6184 - 评论：2 https://www.doczj.com/doc/4e9633577.html, 徐丽红王佰营 A、InternationalRectifier公司--56KHz 输出功率推荐磁芯型号 0---10W EFD15 SEF16 EF16 EPC17 EE19 EF(D)20 EPC25 EF(D)25 10-20W EE19 EPC19 EF(D)20 EE,EI22 EF(D)25 EPC25 20-30W EI25 EF(D)25 EPC25 EPC30 EF(D)30 ETD29 EER28(L) 30-50W EI28 EER28(L) ETD29 EF(D)30 EER35 50-70WEER28L ETD34 EER35 ETD39 70-100W ETD34 EER35 ETD39 EER40 E21 摘自InternationalRectifier,AN1018-“应用IRIS40xx系列单片集成开关IC开关电源的反激式变压器设计” B、ELYTONE公司https://www.doczj.com/doc/4e9633577.html, 型号输出功率（W） <5 5-10 10-20 20-50 50-100 100-200 200-500 500-1K EI EI12.5 EI16 EI19 EI25 EI40 EI50 EI60 -- EE EE13 EE16 EE19 EE25 EE40 EE42 EE55 EE65 <5 5-10 10-20 20-50 50-100 100-200 200-500 500-1K EF EF12.6 EF16 EF20 EF25 EF30 EF32 -- --

磁芯参数

Ferrite For Switching Power Supplies TECHNICAL DATA EI Cores (EI12.5 to EI60) EE Cores (EE10/11 to EE62.3/62/6) EER Cores (EER25.5 to EER42/42/20) ETD Cores (ETD19 to ETD49) PQ Cores (PQ20/16 to PQ50/50) LP Cores (LP23/8 to LP32/13) RM Cores (RM4 to RM14) EPC Cores (EPC13 to EPC30)

EI Series EI12.5 Cores(JIS FEI 12.5) ? Coil: ?0.2 2UEW 100Ts NI limit vs. A L -value for A L -value vs. Air gap length for Temperature rise vs. Total loss for PC40EI12.5 gapped core (Typical) PC40EI12.5 core (Typical) EI12.5 core (Typical) (Ambient temperature: 25°C) Parameter Core factor C 1mm –1 1.48Effective magnetic path length e mm 21.3Effective cross-sectional area Ae mm 214.4Effective core volume Ve mm 3308Cross-sectional center leg area A cp mm 211.6Minimum cross-sectional area A cp min.mm 210.8Cross-sectional winding area of core Acw mm 217.3Weight (approx.) g 1.9 7.4±0.1 2.3 5.1±0.1 8.8–0 1.6 1.6 12.4±0.3 2.4±0.1 4.85±0.15 12.4±0.3 1.5±0.1 4.85±0.15 Dimensions in mm Part No.A L -value (nH/N 2) Core loss (W) at 100°C Calculated output power (forward converter mode)100kHz, 200mT PC40EI12.5-Z 1200±25% (1kHz, 0.5mA)?2120 min. (100kHz, 200mT) 0.12 max. 8.8W (100kHz) Note: NI limit shows the point where the exciting current is 20% and 40% away from its extended linear part. Measuring conditions ? Coil: ?0.2 2UEW 100Ts ? Frequency: 1kHz ? Level: 0.5mA Note: The temperature rise is measured in the room whose temperature and humidity are fixed to 25°C and 45(%)RH. respectively. (approx. 400×300×300cm) 101102 N I l i m i t (A T ) A L -value (nH/N 2) 102 10 1 40%Temperature: 100?C 20% 101 102 A L -v a l u e (n H /N 2) Air gap length (mm ) 1 0.1 Center leg gap Spacer gap 50 100 T e m p e r a t u r e r i s e o f h o t s p o t ?T (?C ) Total loss Pm (W ) 00.2 0.40.60.81 Measuring point Coil Core