This article represents the most frequently asked questions (FAQ) on TDK (Epcos) ferrite cores characteristics and fields of application.
Q: The catalog says "The operating temperature is between -40°C to +85°C, but there are cases where this can vary depending on the material.” Does this mean that it can be used at over +85°C when there is quite a margin with the Curie temperature? ?
A: The general temperature range of electronic components is sometimes applied for operating temperatures. In actuality, ferrite cores have a ”Curie temperature” so they can be used as magnetic bodies until they reach this temperature. However, there are many power supply transformers where the bottom temperature of the core loss of the ferrites is between +80°C and +100°C, and there is the risk of a thermal runaway due to increased core loss --> heating --> increased core loss --> heating if they are used at temperatures of over +85°C.
Q: The catalog says “operating temperature: –30 to +105°C and gives a storage temperature that is lower stating “storage temperature: –30 to +85°C, but isn’t it the opposite?
A: ТThe storage temperature in the catalog is stated on the premise that the product is in its package so there is the concern of a malfunction if it is stored at over +85°C. +105°C is fine with single ferrite body.
Q: Please explain how to wash ferrite cores.
A: Any solvent can be used to wash ferrite cores as long as it is not an extremely acidic solvent (because ferrites are oxides and are chemically stable). For example, there are none that we particularly recommend, but using alcohol has no effect on characteristics or quality..
Q: What serves as a replacement for a H7C1 (PC30) material?
A:A PC47 material may be optimal as a replacement because of its low core loss and high saturation magnetic flux density, but may not be compatible due to shape. Please consult us if you are considering one.
Q:Are there any documents on the model numbers, dimensions, etc. of the P series ferrite cores for Ni-Zn coils?
A: Products in the Ni-Zn ferrite core series are all custom-ordered because they do not come in any standard shapes. We can determine whether we can produce them for you if you let us know of the external dimensions of the P core and the materials. Please consult with a distributor near you if you are looking for a customized product. We recommend you to consult our managers.
Q :What are the characteristics of Mn-Zn ferrites?
О:The characteristics of Mn-Zn ferrites are typified by their high permeability and magnetic flux density, and they are low-loss at just a few MHz. In order to get detailed information you can follow the following links on our web-site : "Epcos ferrite materials" и " TDK ferrite materials"
Q:What are the characteristics of Ni-Zn ferrites?
A: The characteristics of Ni-Zn ferrites are typified by their extremely high resistivity and their permeability being generally a few hundred or below, and they are low-loss at 1MHz and over.
О:The characteristics of Mn-Zn ferrites are typified by their high permeability and magnetic flux density, and they are low-loss at just a few MHz. In order to get detailed information you can follow the following links on our web-site : "Epcos ferrite materials" и " TDK ferrite materials"
Q:What is “initial permeability μi?
A: It is the amplitude permeability of the magnetic core when the intensity of the magnetic field is unboundedly close to “zero”.
*The symbol and the catalog of this data are in accordance with IEC Publication 60401-3.
Q:What is amplitude permeability μa?
A: It is the relative permeability acquired from the maximum value of the magnetic flux density and the maximum value of the intensity of the magnetic field when there are periodic changes in a magnetic core that is in a demagnetized state and a magnetic field that makes the average value of the intensity “zero” is applied.
* The symbol and the catalog of this data are in accordance with IEC Publication 60401-3.
* Our terminology and settings were established by reference to JIS C 2560-1,-2.
Q: What is inductance coefficient АL?
A:
It is the self-inductance that is generated in units of the winding of a coil with a given shape and dimensions wound on a magnetic core, as shown in the following formula.
It is normally represented in units of 10-9nH.
L - Self-inductance of the coil when there is a magnetic core (H)
N - Total number of turns of the coil
* The symbol and the catalog of this data are in accordance with IEC Publication 60401-3.
* Our terminology and settings were established by reference to JIS C 2560-1,-2.
