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Requirements Of Power Supply Technology For Electronic Transformers



Power technology to the requirements of electronic transformers, like all products as a commodity, is the specific use of the conditions to complete the specific function in the pursuit of the best performance price ratio. Sometimes it may be biased towards price and cost, sometimes with efficiency and performance. Now, light, thin, short, small become the development direction of electronic transformers, is to emphasize the cost reduction. From the general requirements of the electronic transformers can be four specific requirements: the use of conditions, the completion of functions, improve efficiency, reduce costs.

Conditions of use of electronic transformers, including two aspects:
Reliability and electromagnetic compatibility. Previously only attention to reliability, now due to environmental awareness enhancement, must pay attention to electromagnetic compatibility. Reliability refers to the use of the specific conditions, electronic transformers can work to the normal life. Ambient temperature is the most important factor for electronic transformers in general conditions of use. It is the Curie point of the soft magnetic material to determine the temperature-affected strength of the electronic transformer. The Curie point of soft magnetic material is high, which is affected by temperature, and the Curie point of soft magnetic material is very low, which is sensitive to temperature change, and is affected by temperature. For example, the Curie point of Mn-Zn ferrite is only 215 ℃, the ratio is low, flux density, permeability and loss vary with temperature, except for normal temperature of 25 ℃, but also give 60 ℃, 80 ℃, 100 ℃ parameter data. Therefore, the working temperature of Mn-Zn ferrite cores is generally limited to 100 ℃, that is, when the ambient temperature is 40 ℃, the temperature rise must be lower than 60 ℃. The Curie point of cobalt-based amorphous alloy is 205 ℃, also low, and the use temperature is limited to 100 ℃. The Curie point of fe-based amorphous alloy is 370 ℃, which can be used under 150℃~180℃. The Curie point of the high magnetic conductivity MO alloy is 460 ℃ to 480 ℃, which can be used under 200℃~250℃. The Curie point of Microcrystalline nanocrystalline alloy is 600 ℃, and orientation silicon steel Curie point is 730 ℃, which can be used under 300℃~400℃. Electromagnetic compatibility means that electronic transformers do not produce electromagnetic interference to the outside world, but also can withstand the external electromagnetic interference. Electromagnetic interference includes audible audio noise and inaudible high-frequency noise. The main reason of electromagnetic interference caused by electronic transformer is the magnetostrictive of magnetic core. The electromagnetic interference caused by the soft magnetic material with large magnetostriction coefficient is large. The magnetostriction coefficients of fe-based amorphous alloys are usually the largest (27~30) x10-6, and measures to reduce noise interference must be taken. The magnetostriction coefficient of high magnetic conductivity Ni50-mo alloy is 25x10-6, and the magnetostriction coefficient of Mn-Zn ferrite is 21x10-6. These 3 kinds of soft magnetic materials are easy to produce electromagnetic interference materials, in the application to pay attention to. The magnetostriction coefficient of 3% oriented silicon Steel is ($number) x10-6, and the magnetostriction coefficient of microcrystalline nanocrystalline alloy is (0.5~2) x10-6. These 2 kinds of soft magnetic materials belong to the material which is more easy to produce electromagnetic interference. 6.5% the magnetostriction coefficient of silicon steel is 0.1×10-6, the magnetostriction coefficient of Ni80-mo alloy with high magnetic conductivity is (0.1~0.5) x10-6, the magnetostriction coefficient of cobalt based amorphous alloy is 0.1×10-6 below. These 3 kinds of soft magnetic material belong to the material that is not very easy to produce electromagnetic interference. The frequency of electromagnetic interference generated by magnetostrictive is generally the same as that of an electronic transformer. If there is a lower or higher than the operating frequency of electromagnetic interference, that is caused by other reasons.