| 主题：如何在开关电源设计中选择最合适的高功率电感的磁芯 |
| 在线问答： |
| [主持人：ChinaECNet] |
各位听众（网友），上午好！欢迎参加中电网在线座谈。今天，我们有幸邀请到Magnetics(美国磁性材料公司)公司的专家就“如何在开关电源设计中选择最合适的高功率电感的磁芯”举行在线座谈。在座谈中，您可就您关心的问题与Magnetics (美国磁性材料公司)公司的专家在线进行直接、实时的对话交流。中电网衷心希望通过大家的共同努力，不仅能够增进各位听众（网友）对“如何在开关电源设计中选择最合适的高功率电感的磁芯”的了解和掌握，而且能够为大家事业的发展带来裨益。 |
[2009-2-17 10:12:26] |
| [主持人：ChinaECNet] |
我们已经进入问答阶段如果听众想重温演讲或内容可以点击下面“回顾演示”重看演讲。 |
[2009-2-17 10:32:59] |
| [问：lzj5418] |
请对铁硅铝磁粉芯(Sendust)、高通量磁粉芯(NiFe50)和钼坡莫磁粉芯(MPP)三种作一简单介绍 |
| [答：Alan] |
Sendust has relatively low core loss between MPP and high flux. Since it does not contain Nickel, it is the cheapest powder core among the others and that"s why it is quite popular used in switching power supplier. It is fairly high saturation flux density (1050mT) which is good in high power application as magnetic storage component.
High Flux has 50% Nickel and has the highest saturation flux density (1500mT). With such high saturation flux density, the size can be reduced to a resonable size. However, it has the highest core loss comparing the others. It is used in extremely high power application where Sendust can"t handle.
MPP consists of 80% Nickel which is the most expensive core among the others. However, it has a fairly high satuation flux density (750mT) which is greater than ferrite core. Also, MPP has the minimum core loss comparing the others, so if the efficiency is a concern in your design, then MPP is your best choice. |
[2009-2-17 10:34:08] |
| [问：laogcs] |
现在高功率电感的磁芯一般有：
1）铁氧体+气隙
2）非晶+气隙
3）铁硅铝环
从损耗和体积的角度出发哪种比较好？ |
| [答：Alan] |
The best of the choice in terms of core loss and size will be gapped amorphous cores since it can provide extremely high saturation flux density. Also, core loss is the minimum among the others due to its characteristics |
[2009-2-17 10:39:19] |
| [问：cjthz] |
开关电源设计中选择高功率电感的磁芯要素有哪几条？ |
| [答：Alan] |
1. Saturation flux density
2. DC Bias point (make sure the core will not saturate)
3. Core loss
4. Core Shape and dimensions
5. Material used
6. Cost |
[2009-2-17 10:43:15] |
| [主持人：ChinaECNet] |
各位观众，现在用户提问很踊跃，专家正在逐一回答。请耐心等待您问题的答案，同一问题请不要多次提交。 |
[2009-2-17 10:48:34] |
| [问：fhdz2004] |
请问：在电动机控制中EMI滤波器的磁芯一般的选取原则是怎样的呢？
谢谢解答 |
| [答：Alan] |
It has to be high permeability material and frequency range |
[2009-2-17 10:49:40] |
| [问：sunrain618] |
铁氧体磁心与磁粉芯在高功率设计中有哪些优缺点？ |
| [答：Alan] |
gapped ferrite:
Disadvantage:
1. Easy to be saturated (not soft saturation)
2. Temperature unstability
3. Fringing loss
4. Low saturation flux density
Adaventage:
1. High effective permeability
2. Tight tolerance up to +/-3%
3. More selection in core shape and geometry
Iron Powder:
Disadvantage:
1. High core loss at high frequency application.
2. Thermal aging
3. Magnetostriction (high pitch noise)
Advantage:
1. Low cost material
2. High saturation flux density
3. Good DC bias (soft saturation)
|
[2009-2-17 10:56:16] |
| [问：tianjiu] |
请问：铁硅铝的软饱和特性主要有哪些优点？ |
| [答：Alan] |
Fault tolerant is the key advantage to protect the circuit even when short circuit is happened, unlike gapped ferrite where small amount of current can go into the saturation region. |
[2009-2-17 11:00:06] |
| [问：tianjiu] |
请问：提高铁硅铝的有效磁导率，会受到哪些因素的限制？ |
| [答：Alan] |
As I mentioned in the presentation, the maximum effective perm of Sendust is 125u at this moment due to the capability of pressing. |
[2009-2-17 11:02:39] |
| [问：ping0489] |
設計電路時需注意的磁蕊參數有哪些 |
| [答：Alan] |
1. permeability
2. saturation flux density
3. Temperature range
4. DC bias
5. Core loss
6. Frequrncy |
[2009-2-17 11:03:58] |
| [问：jingjie24] |
漏感对开关电源有较大影响，这样控制？怎样提高变压器的质量？ |
| [答：Alan] |
Improve winding practice. A neat winding reduces the leakage inductance. Also, higher permeability also improves the leakage inductance. In general, one needs to balance the highest inductance, DC-bias and the lest number of turns to minimize the leakage inductance. Indirectly, loss is playing a factor – a combination of permeability, DC-bias, core loss and copper loss.
|
[2009-2-17 11:05:16] |
| [问：sheldon] |
铁硅铝的形状是否可以按照客户的要求随意改变？ |
| [答：Alan] |
Sometimes not, but we need to see what geometry or dimensions you want. |
[2009-2-17 11:07:06] |
| [问：dwh000] |
133直径的环形铁硅铝在100KHz下可以做到多大功率 |
| [答：Alan] |
About 10KVA. |
[2009-2-17 11:08:45] |
| [问：cuchan] |
对于开关电源设计时从那些方面考虑电感的磁芯的选择？ |
| [答：Alan] |
1. Saturation Flux density
2. DC bias
3. Core loss
4. Temperature rise
5. Frequency
6. Material used
7. Shape/core geometry |
[2009-2-17 11:11:15] |
| [问：lzj5418] |
较大的直流偏场下，要保证电感值的最小直流漂移可选择哪种磁芯？
|
| [答：Alan] |
Amorphous core |
[2009-2-17 11:11:40] |
| [问：laogcs] |
贵公司的环铁芯允许最大的安匝数是多少？我公司在产品中用到1200A、5mH 滤波电感。是用冷轧硅钢大型C型铁做的。有没有可能用贵公司的铁芯来制作？ |
| [答：Alan] |
We use oersteds for this quantity. Our cores can go up to 1000 oes. It seems our product can fit your application. |
[2009-2-17 11:15:01] |
| [问：PETERZHOU] |
同等功率的变压器,铁硅铝与铁氧体相比,成本和体积上有何优势?
谢谢 |
| [答：Alan] |
Cost is more depending on the permeability, but the size can reduce about 30%-35% comparing to gapped ferrite. |
[2009-2-17 11:16:25] |
| [问：jinxuequn] |
同一款磁芯，如EE25，有得开关电源变压器厂家对磁芯同时有直流叠加特性和功率损耗的要求，而有的厂家只要求功率损耗。我想请教：
1、这是基于什么不同的设计思路？
2、哪一种更优？或者两者利弊何在？
谢谢！ |
| [答：Alan] |
The requirement for both DC-bias and efficiency is certainly a better design consideration. Because it takes care of the efficiency and the high current option. Although DC-bias may not always needed at high DC-bias current, it is a safety feature to include DC-bias requirement. |
[2009-2-17 11:16:49] |
| [问：dwh000] |
磁芯开气隙有什么注意事项 |
| [答：Alan] |
1. Size of grinding wheel
2. Type of grinding
2. Speed of grinding |
[2009-2-17 11:18:30] |
| [问：tianjiu] |
请问：铁硅铝材料的工作温度可以达到多少？ |
| [答：Alan] |
200C continuously operated. |
[2009-2-17 11:19:00] |
| [问：tianjiu] |
请问：铁硅铝的主要优点可以概括为哪几点？ |
| [答：Alan] |
1. Faily high saturation Flux density (1050mT)
2. Soft saturation (no sharp saturation)
3. Relatively low core loss
4. Temperature stability
5. Frequency stability
6. No thermal aging
7. Near zero magnetostriction
|
[2009-2-17 11:22:57] |
| [问：davenzhangxi] |
kool高频噪声大吗 |
| [答：Alan] |
Not at all. |
[2009-2-17 11:24:29] |
| [问：sheldon] |
铁硅铝的成本较高，不太适合现在的设计的成本需求，未来铁硅铝是否可以降低本身的成本压力？ |
| [答：Alan] |
Please refer to our sales department for price issue. |
[2009-2-17 11:26:15] |
| [问：lmyzju] |
what is the difference between Toroids Koolmu and E Koolmu? |
| [答：Alan] |
E core has wider window area than toroids. |
[2009-2-17 11:27:41] |
| [问：yangsongying] |
请问专家如何解决损耗度的问题，谢谢！ |
| [答：Alan] |
Core loss absolutely depends on the core material itself. If efficiency is a concern, then amorphous material is used. If not then, powder core like Kool Mu, MPP or High flux can be used. If price is an issue, then you could choose gapped ferrite or even iron powder. |
[2009-2-17 11:31:22] |
| [主持人：ChinaECNet] |
各位观众，现在用户提问很踊跃，专家正在逐一回答。请耐心等待您问题的答案，同一问题请不要多次提交。 |
[2009-2-17 11:31:51] |
| [问：PETERZHOU] |
铁硅铝的工作频率可以最大为多少?
谢谢 |
| [答：Alan] |
20MHz. But people do not usually operate at this frequency. |
[2009-2-17 11:32:09] |
| [问：sheldon] |
PPT中说铁硅铝不随温度变化而变化，很稳定，但是其他的外界条件呢，比如湿度，经纬度等？ |
| [答：Alan] |
For more informaiton, ou could refer to our web-site and see the temperature stability curve for Kool Mu. |
[2009-2-17 11:35:10] |
| [问：lzj5418] |
磁芯磁性波动范围控制在±0.5%以下能否满足？ |
| [答：Alan] |
No. The reason is sometimes the tolerance of the tool is higher than this. |
[2009-2-17 11:36:13] |
| [问：tianjiu] |
请问不同厂家的铁硅铝在性能上有多大差别？ |
| [答：Alan] |
Basically the core loss and DC bias are not the same. You need to test the smaple to verify these. |
[2009-2-17 11:37:24] |
| [问：xinlike] |
磁芯的磁导率最大能到多少，最小能到多少？ |
| [答：Alan] |
As far as I know, the highest is 20,000 and the lowest is 14. |
[2009-2-17 11:38:43] |
| [问：fhdz2004] |
请问专家，我是做电机驱动的，只用有直流有刷和交流电机，为了通过EMC电磁兼容试验，需要有差模和共模的滤波器，在磁芯的选择上，我看到一般都是铁氧体，专家有什么建议呢？ |
| [答：Alan] |
For common mode and differential mode chokes, I would also suggest ferrite because of the price. |
[2009-2-17 11:41:09] |
| [问：PETERZHOU] |
贵公司的铁芯可否定制?
谢谢 |
| [答：Alan] |
Yes. Please submit the drawing for verification. |
[2009-2-17 11:41:49] |
| [问：wureyes] |
Just you introduce Sendust core, could you show us your MPP or High flux characteristic? |
| [答：Alan] |
High Flux has 50% Nickel and has the highest saturation flux density (1500mT). With such high saturation flux density, the size can be reduced to a resonable size. However, it has the highest core loss comparing the others. It is used in extremely high power application where Sendust can"t handle.
MPP consists of 80% Nickel which is the most expensive core among the others. However, it has a fairly high satuation flux density (750mT) which is greater than ferrite core. Also, MPP has the minimum core loss comparing the others, so if the efficiency is a concern in your design, then MPP is your best choice. |
[2009-2-17 11:43:15] |
| [问：sheldon] |
铁硅铝是美国磁性材料公司的独家专利么？ |
| [答：Alan] |
No, but the name Kool Mu is our registered trademark. |
[2009-2-17 11:44:08] |
| [主持人：ChinaECNet] |
所有问题均已提交给Magnetics (美国磁性材料公司)公司的专家。座谈期间未回答的问题，Magnetics (美国磁性材料公司)公司专家也会逐一回答，并在中电网上公布，请大家注意收看。 |
[2009-2-17 11:54:17] |
| [主持人：ChinaECNet] |
由于时间关系，本次中电网“在线座谈”马上就要结束了。虽然各位听众（网友）已与Magnetics (美国磁性材料公司)公司的专家讨论了许多问题，但是还有许多提问没有来得及进行交流。本次在线座谈结束后，中电网将请Magnetics (美国磁性材料公司)公司的专家继续答复所有的来自各位听众（网友）的提问，然后整理上载到中电网网站上，以便大家查阅。 |
[2009-2-17 11:57:46] |
| [主持人：ChinaECNet] |
在此，中电网特别感谢给予本次中电网在线座谈巨大支持的Magnetics (美国磁性材料公司)公司，特别感谢专门在线回答各位听众（网友）提问的Magnetics (美国磁性材料公司)公司的各位专家们，特别感谢各位听众（网友）积极热情的参与。 |
[2009-2-17 11:58:08] |
| [主持人：ChinaECNet] |
祝大家事业有成、生活愉快！欢迎多提宝贵意见，欢迎关注中电网，下次再见。 |
[2009-2-17 11:59:28] |
| |
非在线问答 |
| [问：ben_U] |
is it possible to use Kool mu to implement integrated magnetics for high-power for large current of low voltage? |
| [答：Magnetics 公司专家] |
The smallest Kool Mu core we can do is 4.19mm in diamenter after coating. I am not sure if this is the size you are looking for. |
|
| [问：bowei181] |
铁硅铝：在噪声抑制方面有什么优越性吗？ Advantages of Kool Mu reagrading contrl nosie? |
| [答：Magnetics 公司专家] |
Comparing to iron powder, Kool Mu cores have less noice in high frequency applications due to low magnetostriction. |
|
| [问：bowei181] |
铁硅铝磁芯适用的频率范围为多少？Applicable frequency range for sendust? |
| [答：Magnetics 公司专家] |
The application frequency of Kool Mu cores can go as high as 20MHz, but normally people will operate them at about 100-500kHz in their design. |
|
| [问：bowei181] |
请问：相关的选型手册哪里有？Any catalogs for seceting cores? |
| [答：Magnetics 公司专家] |
Please visit our website at (http://www.mag-inc.com/library.asp#powder) for more information of our Kool Mu cores' applications. |
|
| [问：cuchan] |
设计参考工具是否可以免费下载 Free to download Design tool from your website? |
| [答：Magnetics 公司专家] |
Please visit our website at (http://www.mag-inc.com/software/software.asp) for more information of our design tool. I would highly recommend you to use Magnetic Builder that has everything you need and the most updated software design tool. |
|
| [问：fshancl] |
请问工作在20kHz的功率电感所选择的磁芯，从磁饱和密度和导磁率上折中用哪种好？为什么？ 谢谢！Concerning with density and the permeability, what types of powder cores should be chosen for 20KHz inductor? Why? |
| [答：Magnetics 公司专家] |
If price is an issue, then iron powder or laminated silicon steel could be used. If you really want high permeability and Bast, then amorphous cores might be used. Howver, Kool Mu cores can also be used in 20kHz and the performance will be between iron powder and amorphous cores. |
|
| [问：fshancl] |
铁硅铝芯的综合最佳工作频率是多少？What's the best frequency of sendust? |
| [答：Magnetics 公司专家] |
The application frequency of Kool Mu cores can go as high as 20MHz, but the best usable frequency range will be about 1MHz. |
|
| [问：johnny zhong] |
Do magnetics' products have the price merit |
| [答：Magnetics 公司专家] |
Please contact our sales department for price issue. |
|
| [问：gaon] |
不知道是不是能讲一下不同材质的成本比较.谢谢 Please compare the costs with different materials |
| [答：Magnetics 公司专家] |
Please contact our sales department for price issue. |
|
| [问：gaon] |
圆柱型中柱,目前最大有多少的.圆型的较方型的有不足的地方吗.谢谢 wha's the largest size of cylindrical shape? Disadvantages compaing with square one? |
| [答：Magnetics 公司专家] |
The round center post core that Magnetics offers is only ER18 at this moment. The disadvantage of round center post is more expensive comparing with the traditional rectangular post. |
|
| [问：licki518] |
针对不同应用场合,我们在选择开关电源时,需要从哪些角度上考虑磁芯材料? What need to concern when select cores for SPS design? |
| [答：Magnetics 公司专家] |
1. Core loss
2. Saturation flux density
3. Operating frequency range
4. Temperature range
5. Shapes and geometry
6. Price |
|
| [问：xujian2005] |
在PFC中的输出电感其铁芯的选用是否铁粉芯比铁氧体磁芯更合适一些？从性能价格比角度看。Is iron powder better than ferrites for cores used in PFC inductor, from the point of veiw - perfomance vs cost? |
| [答：Magnetics 公司专家] |
Performance: Iron powder is better than gapped ferrite since it has higher Bast and size of the core will be smaller.
Price: Ferrite corer are cheaper than iron powder.
But if you really want very good performance, you need Kool Mu cores as I already explain in the seminar. |
|
| [问：xujian2005] |
平面变压器（的类型）现在可否做到1KVA左右的输出功率，假设开关频率在300KHz---500KHz左右，谢谢！Can a planar transformer be designed with 1KVA power output at frequency between 300 to 500 KHz? |
| [答：Magnetics 公司专家] |
Magnetics's planner E-I ferrite core 5810 or can offer you up to 300kHz and about 1KV application. |
|
| [问：yangsongying] |
铁硅铝材料的成本如何？谢谢 cost of Kool Mu? |
| [答：Magnetics 公司专家] |
Please contact our sales department for price issue. |
|
| [问：yangsongying] |
What's the advantage of the Kool mu? |
| [答：Magnetics 公司专家] |
Reasonably high Bmax (1050mT)
Soft saturation
Low core loss than iron powder & High Flux cores
Low magnetostriction (low noise)
No thermal aging
Stable performance to high temperature
No fringing loss as appeared in gapped ferrite |
|
| [问：zhangzhang09] |
1 设计电路时 电感的感值怎么选择？
2 电感的大小和电路的动态响应有什么关系？谢谢！How to select AL value? What's the connection between inductance and circuit response? |
| [答：Magnetics 公司专家] |
Inductance really depends on your circuit and is up to design engineers. If the inductance is too low, it might be risky since it might run into saturation which might cause fire or damage eventually. |
|
| [问：zhangzhang09] |
在实际电路中怎么选择电感的大小？How to determine inductance in a circuit design? |
| [答：Magnetics 公司专家] |
Inductance really depends on your circuit and is up to design engineers. It is very difficult to say how much inductance it is good for one specific design. |
|
| [问：liyugongVIP] |
请问:大功率200W,小尺寸用平面变压器,+_100V驱动负载,用何种芯温度最低?high-power 200W, planar transformer with small size, + _100V driven load, what powder cores to use to minnimize temperature? |
| [答：Magnetics 公司专家] |
What circuit topology are you using? What is the switching frequency of your design? |
|
| [问：herman_mo] |
请推荐电流20A左右的电感，谢谢！Please recommend the inductor current of about 20A |
| [答：Magnetics 公司专家] |
What is the number of turns in your design? What is the biggest allowable size of the core? |
|
| [问：blueshinywangxian] |
如何选择在同一设计中，开关电源工作频率从200KHz连续工作到1MHz的高功率电感的磁芯（200W，1/8砖模块），使得开关电源可以在这一条件下长时间高效率工作，并且损耗最小。 |
| [答：Magnetics 公司专家] |
Our Kool Mu cores should be able to meet your requirement. You need to specify your number of turns in order to deceide the required DC magnetizing force which affects the effective permeability. Please visit our website (http://www.mag-inc.com/library.asp#powder) for details of our Kool Mu. |
|
| [问：kkkk9942] |
设计电路时有什么要特别要注意的 what are concerned for power supply design? |
| [答：Magnetics 公司专家] |
There are so many aspects you need to pay attention. I will only give you all the criteria for power inductors and transformers design in switching power supply.
1. Core loss
2. Saturation flux density
3. Operating frequency range
4. Temperature range
5. Shapes and geometry
6. Price |
|
| [问：sunrain618] |
现在有哪些对对电感性能测试的有效的比较好的测试工具或者手段？What would be the better tools for testing inductor performance? |
| [答：Magnetics 公司专家] |
LCR meter (HP 4284) can offer you very accurate inductance measurements. Core loss meter (Yokogawa) can give you very accurate core loss measurement. |
|
| [问：shaoziyang] |
在小功率的DC/DC中，使用铁硅铝磁粉芯有优势吗？What are the advantages to use sendust in low power DC/DC? |
| [答：Magnetics 公司专家] |
Low profile and for high current applications
Minimize magnetic flux leakage
Excellent DC bias characteristics
Good heat dissipation and temperature stability
Large energy storage capacity
Mounting on the PCB directly |
|
| [问：shaoziyang] |
铁硅铝磁粉芯在价格上与其他磁芯相比是否更高？ Is kool mu more expensive than any other magnetics cores? |
| [答：Magnetics 公司专家] |
Please contact our sales department for price issue. |
|
| [问：lyshao] |
PowerEsim设计出的变压器和电感参数还需再次调整吗? Do those inductance parameters I got from Power Esim design need to be adjusted? |
| [答：Magnetics 公司专家] |
Power Esim will give you a direction of the inductor design which is fairly good. However, you need to do testing in order to have an optimum design. |
|
| [问：sjl@nange.com] |
如何选择低电压大电流高功率电感 How to choose a high-power inductor that is with low voltage and high current ? |
| [答：Magnetics 公司专家] |
DC Magnetizing force (current & number of turns) and permeability (inductance) are directly proportional. You need to knoe these informaiton in order to determine the size and the material of the core. |
|
| [问：xinlike] |
磁芯可以做为滤波器吗？Can cores be used to make filtes? |
| [答：Magnetics 公司专家] |
Magnetic cores can be used as filters depending on its material used. What kind of filter are you working on? Please send me more information so I can help you out. |
|
| [问：mp44] |
资料有中文版的吗 can you provide Chinese version? |
| [答：Magnetics 公司专家] |
Yes our materials do have Chinese version. Please visit our web-site at (http://www.mag-inc.com/library) for details. |
|
| [问：mp44] |
Magnetics 有选型样本或手册吗 provide samples or catalogs? |
| [答：Magnetics 公司专家] |
If you need samples or product catalogues, please contact us. You could also visit our website at (http://www.mag-inc.com) for details. |
|
| [问：mp44] |
设计过程实例的网址是什么 wesite for examples of design process? |
| [答：Magnetics 公司专家] |
Please visit our website at (http://www.mag-inc.com/software/software.asp) for details. |
|
| [问：sheldon] |
铁硅铝在制造时不需要有机粘合剂，那么它是如何粘合的？How to bond sendust togeter since you don’t use organic binder when manufacuring,? |
| [答：Magnetics 公司专家] |
Kool Mu cores use inorganic binder instead of organic one to eliminate thermal aging. |
|
| [问：chenty] |
从目前来看哪类磁芯较有发展前景？Which type of powder core is with higher potenial? |
| [答：Magnetics 公司专家] |
It really depends on what power rating you are looking for. For low power applications, ferrite cores will be preferred. For medium and high power applications, powder and amorphous cores will be suitable. |
|
| [问：PETERZHOU] |
能否提供样品服务? Can you offer free samples? |
| [答：Magnetics 公司专家] |
Yes Magnetics does provide free samples to our customers. Please contact us for details. |
|
| [问：PETERZHOU] |
铁硅铝的最大工作和储存温度为多少? Maximum temperature of using sendust?
谢谢 |
| [答：Magnetics 公司专家] |
Maximum continuous temperature is 200C due to the limination of the coating. The core itself can go as high as around ~500C. |
|
| [问：PETERZHOU] |
铁硅铝可以进行机械加工成型吗(即不必开成型模具)? Can senduct be used with (in) molding machine?
谢谢 |
| [答：Magnetics 公司专家] |
Yes you could do machine sample with Kool Mu E-cores, U-cores and I-cores, but most of the shape will be toroid so machine samples might not be applied. |
|
| [问：PETERZHOU] |
贵公司在上海有办事处吗? Do you have office in Shanghai?
谢谢 |
| [答：Magnetics 公司专家] |
No but we have a representative called Jason Gong and you could contact him at jgong@spang.com for price and sample request issues. |
|
| [问：c150] |
贵公司是否有高频磁性材料产品？（可应用于HF甚至是UHF的）Do you provide high flux magetnics product (applied in HF and/or UHF) |
| [答：Magnetics 公司专家] |
Our Kool Mu cores (26u) can go to as high as 20MHz and are good for high frequency applications. We do not have the products that can handle UHF band. |
|
| [问：c150] |
在开关电源中，电感是否是损耗最大的部件？Is the major loss from industance In a SPS design? |
| [答：Magnetics 公司专家] |
Both magnetic parts and power MOSFETs will dominate the power loss in SPS depending on your design. |
|
| [问：c150] |
磁罐和磁芯比较有什么优劣？Differences between magnetics pot and powder cores? |
| [答：Magnetics 公司专家] |
Advantages of Pot core (磁罐):
1. Excellent EMI Shielding
2. Low winding cost
3. Easy to assembly
Disadvantages of Pot core (磁罐):
1. Very high cost
2. Poor heat dissipation
3. Not suitable for power application |
|
| [问：c150] |
请问如何从外观上判断磁芯的材料？How to judge different materials from the appearances of cores? |
| [答：Magnetics 公司专家] |
It is hard to visually determine the material of the core. For example, most of the toroids will be coated with epoxy and there is no way to visually determine the material of the core. |
|
| [问：c150] |
请问有离线的设计工具下载吗？An offline design tools software can be used? |
| [答：Magnetics 公司专家] |
Yes we do, but those are very old and they do not have the most updated information. You could still use them, but I would highly recommend you to use our on-line software design tool. You could save your work directly into your computer if you cannot finish it and load it the same file again when you work on it next time. |
|
| [问：c150] |
请问有没有适合30Mhz的磁芯？Powder cores for 30MHz design? |
| [答：Magnetics 公司专家] |
No. The highest we have is 20MHz. |
|
| [问：c150] |
请问在武汉有代理吗？Any distributors in Wu Han City? |
| [答：Magnetics 公司专家] |
No, but we have a sales representative (Jason Gong) at Shanghai and he can serve you if you need the quotation or even sample request. |
|
| [问：lzj5418] |
国内有没有生产E1形状的金属软磁粉芯的公司？any suppliers in China that provide E shape powder cores? |
| [答：Magnetics 公司专家] |
You could check it from the Internet. |
|
| [问：lzj5418] |
哪种磁芯的有效导磁率更高？What type of powder cores with higher effective permeability? |
| [答：Magnetics 公司专家] |
High permeability Nickel-Zine ferrite cores can have permeability up to 20,000. |
|
| [问：lzj5418] |
通信电源中做一个0-80V的可调电源,请问能不能做一个3000W 220Vac输入0-80V输出的开关电源设计？How to do a 3000W 220Vac input 0-80V output switching power supply design, similar to a adjustable 0-80V power supply in Communication Power Supply design? |
| [答：Magnetics 公司专家] |
It is possible depending on the circuit topology and design. |
|
| [问：lzj5418] |
想做一个120W的反激式开关电源，请问用什么IC可以达到呢? What kinds of IC can be used to produce do a 120W flyback switching power supply? |
| [答：Magnetics 公司专家] |
You should contact semi-conductor suppliers as we are the magnetic core manufacturer. |
|
| [问：lzj5418] |
30兆赫的频带下能否使用？Cores that can be used at 30 MHz? |
| [答：Magnetics 公司专家] |
No. The highest we have is 20MHz. |
|
| [问：lzj5418] |
磁粉芯与铁氧体的饱和磁通密度哪个高？Is powder core or ferrite with higher saturated magnetic flux density? |
| [答：Magnetics 公司专家] |
As I mentioned in the seminar, powder cores have much higher saturation flux density than ferrite cores. |
|
| [问：phosphor] |
除了在材料选择,还应该在哪些方面进行成本控制? Other than materials selctions, how to better contrl costs? |
| [答：Magnetics 公司专家] |
Since materials determine the characteristics and performance, cost will definitely base on them. |
|
| [问：wanghx] |
铁氧体磁芯的传导功率是如何计算的？How to calculate Ferrite Cores conduction power ? |
| [答：Magnetics 公司专家] |
Our ferrite core loss formula contains both hysteresis and eddy current losses without DC bias. Please see our website at http://www.mag-inc.com/ferrites/ferrites.asp for details. |
|
| [问：laogcs] |
能够提供产品手册吗？Can you provide catalogs? |
| [答：Magnetics 公司专家] |
Please go to our website at http://www.mag-inc.com/ since we post all the information there. |
|
| [问：laogcs] |
请公布能够下载美国磁性材料公司产品手册的网址 Please advise Magnetics website for downloading catalogs |
| [答：Magnetics 公司专家] |
Please go to our website at http://www.mag-inc.com/ since we post all the information there. |
|
| [问：laogcs] |
外径60~70mm的导磁率125铁硅铝环的AL值是多少？What's the AL value for OD 60-70mm perm 125 sendust? |
| [答：Magnetics 公司专家] |
We do not have 60-70mm Kool Mu toroids at this moment. The best option is OD = 58mm after coating. The AL vaules are 156 (0077109A7) & 287 (0077195A7). Please contact us if you need samples for engineering verification. |
|
| [问：dimin] |
怎样控制成本？How to control cost? |
| [答：Magnetics 公司专家] |
This is a very broad question and you can contact our sales department for quotation. |
|
| [问：dimin] |
高功率会提高成本吗？Will it cost more to use hig-powder cores? |
| [答：Magnetics 公司专家] |
Yes. |
|
| [问：xywangsy] |
你好，问一个简单的问题，什么是磁芯差损 what is core loss? |
| [答：Magnetics 公司专家] |
Core loss is a form of energy loss that occurs in electrical transformers and inductors. The loss is due to a variety of mechanisms related to the fluctuating magnetic field, such as eddy currents and hysteresis. Most of the energy is released as heat, although some may appear as sound ("hum"). Core losses do not include the losses due to resistance in the conductors of the windings, which is often termed copper loss. |
|
| [问：wmq7153] |
设计20W电源，100K和67K频率下，选哪款最合适With 20W power supply design, 100K and 67k frequency, which one is better? |
| [答：Magnetics 公司专家] |
The size of the magnetic parts are directly proportional to switching frequency. Since the rated power is only 20W, there should not be a big difference. If the application were high power (e.g.: 1KW), the size of magnetic parts would be significant and engineers should be aware of them. |
|
| [问：shuochen18] |
请比较磁粉芯与铁粉芯的效率和发热情况，谢谢。Please compare the differences with efficieny , thermal effects between powder cores and iron cores. |
| [答：Magnetics 公司专家] |
Please see my on-line seminar at www.mag-inc.com as I have alreadyexplained it in details. |
|
| [问：ben_U] |
开关频率在1MHz左右，电流峰值接近10A，选择哪种类型的磁芯比较合适？What types of powder cores should be chosen when switching frequency is around 1 MHz and peak current is close to 10A? |
| [答：Magnetics 公司专家] |
Are you designing transformer or inductor? What is the topology of your design? What is the inductance or number of turns of your transformer or inductor? You need to know this in order to complete the design. |
|
| [问：guohuizhang19700919] |
我们目前开发的石油测井仪器，井下仪器必须用高温开关电源。请问这样选择高温的高功率电感的磁芯 ？谢谢 We are currently developing the oil drill equipment that must use high-temperature switching power supply disgn. How to choose cores for high-power inductors design under high tempeture? |
| [答：Magnetics 公司专家] |
Our powder cores (MPP, High Flux & Kool Mu) should be a good choice since they can continuously operate at 200C. If you need samples for testing, please let us know. |
|
| [问：lmyzju] |
怎么能简单地计算出铁氧体磁芯和Koolmu磁芯的饱和电流? How to simply calculate saturation current for Ferrites and Kool mu?
谢谢! |
| [答：Magnetics 公司专家] |
We need to determine the DC magnetizing force (H) in Amp/turns or oersteds since it determines whether or not the core is saturated. H depends on peak current, number of turns and effective magnetic path length of the core. The formula is H = (0.4*pi*N*I)/le with N is number of turns, I is the peak current in A, le is magnetic path length in cm and H is DC magnetizing force in oersteds. Once you have this, you can use our DC bias curve that is listed in our product catalogue and locate the value of H on the curve. Then you will get the corresponding effective permeability from the curve. If the permeability is below 10% (0.1) of the initial permeability, the core is said to be saturated. This is the maximum or saturation currect of the core. But normally engineers will have some design margins and usually take the value at about 20-25% to be more safe in the design. |
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