525uH / 4A common mode inductance common mode choke EMI filter T20-8

タイトルまたは説明

At present, the rapid development of power electronics technology, such as UPS, photovoltaic, wind power systems and grid-connected inverter, inverter and other equipment have to use SPWM carrier
Technology will generate high harmonics, due to the frequency of the main switch has gone from a few KHz, tens of KHz to develop, so the filter inductor made more
High demand. I rely on his master alloy powder core technology, jointly developed series alloy metal powder core inductors, excellent performance to meet the development
Trends requirements.
SPWM inverter carrier class filter inductor has the following characteristics:
1, frequency sine wave (frequency usually *0Hz), requires the use of materials inductors have high Bs value;
2, to be filtered is the carrier frequency of the fundamental wave 1,3,5,7,9,*1 high harmonics, require materials used in the inductor to have a high frequency low
Loss characteristics;
3, the state of the circuit so that the DC component of the inductor at work, the requirement that materials used in the inductor to have an excellent DC stacked Stuttgart
Sex;
4, for the inductor selection of suitable materials designed according to the carrier frequency is designed to meet the requirements of the inductor basic protection, but the actual work
As a condition, designed to meet the dynamic requirements, it is possible to filter out high harmonics, but also make the inductor has a suitable temperature, it is projected to be repeated electrical
Sensor design optimization.

The difference between the metal powder core and ferrite
1, the characteristics of the metal powder core (ferrite contrast) (internal)
and a closed magnetic circuit (to be gapped ferrite with EMI), to the outside world almost no EMI interference in Figure 1;
b Due to the natural distribution of the metal powder core internal gap, avoiding partial loss ferrite like to open the gap caused by too high, causing the hot spot temperature, Yan
Heavy affect the life of the inductor windings Figure 1;
b has a ferrite two times higher Bs, made into an inductor with high power density, reduced by nearly one-third of the volume of comparable ferrite, especially made
Integrated SMD inductors shown in Figure 2;
c metal powder core of the DC bias characteristics of both the DC bias magnetic field and the magnetic permeability (or inductance) changes are easy to get, and a smooth curved law
Linear, saturation process is soft saturation inductors in Figure 3, the actual results according to the curve of the inductor is designed to work in a dynamic and practical basically consistent;
d metal powder core has good resistance to external stress properties, it has a higher reliability:
Because it is the powder metallurgy process, the material is more toughness, resistance to mechanical shock resistance than other soft materials;
Metal powder core has a wider operating temperature range (**5 ℃ ***0 ℃), low temperature coefficient, generally less than **0 ppm;
Transformers and inductors abnormal sound solution
In fact, the audio is abnormal sound vibration, sound vibrations are produced only in the audio range that we can hear, in fact, other electromagnetic interference analogy we call noise, but can not hear, can be measured. So the mechanism of the first vibration analysis probably there are several (you can add friends or challenge) is the core of a magnetostrictive caused by low-frequency applications such as iron heart, silicon materials, because of their magnetostrictive coefficient of the material at low frequencies when relatively large and when a larger design load, the core itself will send some of magnetostrictive vibration, this frequency is precisely what *0KHZ audio, up to a certain strength, the ear will hear, or is a ferrite core applications low frequencies, due to the small design margin, close to saturation, frequency of application is also happen off than lower audible noise; the second winding gap bonding insecure, when power is larger or large load changes, causing the winding wire air between and among audio vibration occurs. (vacuum impregnation, drying gradient is very important to not form toothpaste effect, outside the paint dry, there is no dry, winding no bonding, dielectric constant does not meet the requirements of distributed capacitance have changed the third is the line between the winding and the core package loose when at full load or alternating, when overloaded, winding between the core and the occurrence of an audio oscillator. the fourth, distributed-parameter resonance transformer distribution parameters and circuit an audio signal is generated resonance effect solution first magnetostrictive coefficient is small core replacement; the second vacuum dip viscosity suitable insulating paint, and use the gradient drying process (first low temperature, high temperature gradient to go through To explore the anatomy of transformer technology, which is dry and ensure a strong bond, in fact, solvent-free varnish is better. third, the use of insulating paint viscosity for dipping, or the skeleton and the core point of contact at the epoxy adhesive bonding (industrial module power supply, power supply, high reliability products must do so). The fourth, adjusting transformer distribution parameters, or re-layout, which is difficult to solve, need to experiment and explore.
EMI Solutions suitcase
Speaking of EMI and EMC solutions have had a similar experience people know
On the one hand you want to understand the essential knowledge EMI and EMC, more importantly, the experiment, in order to test it must have sufficient countermeasures element
Deen emi countermeasures program suitcase: there are guiding disc solve EMI, EMI countermeasure program, EMI countermeasure countermeasures element sets (common mode capacitors, inductors common mode, differential mode inductors, common mode inductors, bleeder resistor) Typical circuit and circuit boards. bead spike suppressor. teach you to design a common mode inductors, offers a variety of magnetic and enameled wire guide you to design a variety of inductors electromagnetic interference (EMI) electromagnetic Compatibility EMC, a lot needs to be repeated experiments, but for experimentation requires a variety of components. Xin Shang Rong great convenience to you, so that you get the quick fix of EMI.
After potting or encapsulating inductance reasons for the decline
Shrinkage or expansion during the curing of the adhesive potting core mechanical stress

Due to temperature changes or gum cores is not the same coefficient of expansion and mechanical stress
Use of silicone rubber (potting, bonding, encapsulation) and some of the considerations
Purpose and use of silicone rubber Note: Elastic (absorb vibration, small device for bonding stress) bonding: generally a single component with the flow is not good, very good use of the current application is more common GD**4, bonding strong, fast curing. the price is high, generally used for the military. the adhesive is cured by absorbing moisture in the air gradually solidified from the surface to the interior, the use of glue is not easy too thick, too thick interior may never dry. low thickness potting or three defenses: the general use of single-component silicone rubber **4 more, when the glue is better advantage potting liquidity leveling, good strength after curing, but can not remember the depth of potting, because the class is through glue. absorbing moisture in the air from the surface to the interior sulfide gradually solidified to form a sealed container after the thickness of the surface is too dry, the internal and external isolation inside colloidal gel will not dry. such insulation characteristics affect the insulation resistance is low. Disadvantages generally not very good thermal conductivity, So pay attention to power devices. another chemical reaction to form a gas when glue curing depth potting gas release could not form the air inside the honeycomb, missiles and other military satellites in high-altitude thin air because of external pressure product easy to form a low accident. Two-component thickness potting: when the class after plastic potting glue and hardener separately by a certain percentage ratio liquidity ratio is very good, naturally cured glue may be heated to accelerate the curing (high process efficiency, strong artificial vacuum casting process, not prone pores), but this kind of glue can be divided into two types of a class of thermal conductivity is very good (on behalf of Dow Corning **0 AB after curing gray) a class of thermal conductivity slightly worse (on behalf of GN**1, GN**1) two types of surface hardness after curing glue stick general relay difference (can be used to improve the coupling in preparation), thermal conductivity, good two-component glue, because the internal components of the filler metal is better than the major thermal expansion coefficient, high temperature resistance, but have a greater expansion of low temperature stress on internal components have a greater compressive stress (and therefore must be considered when potting potting internal device and the coefficient of expansion than the matching problem) and therefore be used with caution by temperature stress in more occasions; there is a two-component have a common drawback is prone catalyst poisoning, poisoning not be cured, such as GN**1 and GN**1 coated surface after the ferrite core can not be cured, it is best to consult the manufacturer when used for encapsulation types:. "enclosing class for" doing an explanation for packet when the seal is good liquidity, short curing time, surface hardness after curing (similar to car tire) such material is suitable for encapsulating both elastic (small temperature stress on internal components, but also the hardness (elasticity but also has good tear withdrawal resistance to mechanical stress capability good hardness), now I did not find domestic products, only Germany has a product to meet this requirement. another common feature of silicone products are good jobs and good stability of high temperature insulation performance. own experiences to share with you, Please correct me if wrong.
Rapid application development period planar transformer has come, everybody ready?
Communications industry has been the development of high-frequency power traction. Engine power is also a high-frequency inductive device development. Greatly expanding 3G mobile communications features, is bound to make the electronic system of the base station to increase the electricity board. In the mobile communication base stations, 2.5G previous board electricity primarily using small power supply *0W or less. These small power transformers using SMD skeleton classes and general PCB board as a circuit board technology is more appropriate. And now, with greatly enhanced 3G capabilities, the board should be more than *0W power consumption for the majority, then the above is greater than *0W DC power modules, using a flat aluminum plate circuit plate transformer and the most suitable choice. Therefore, the demand for secondary DC power module *0W***0W will gradually increase, so the demand for planar transformer inductors *0W***0W 3G will further develop with the gradual increases.