With the emergence of new enterprises in various industries and the increasing competition in the market, how to reduce product costs under the premise of ensuring product quality has become a new topic for every enterprise. The following is a brief introduction to how to design a proper switching power supply peripheral circuit according to the electronic product application environment.
In the international standard IEC61000, electronic products are divided into three categories according to the application environment: Class 1 is residential, commercial and light industrial environments; Class 2 is industrial environment; Class 3 is electrical equipment for measurement, control and laboratory use. Use less, here is not to repeat.
The requirements for electromagnetic immunity for Class 1 electronic products are relatively low, and the requirements for conducted radiation are relatively high; while for Class 2 products, the opposite is true, and the requirements for electromagnetic immunity are relatively high. Relatively low. This is due to environmental characteristics, the commercial grid environment is clean, and the industrial grid environment is much more complicated.
For this reason, when the switching power supply is actually applied, this rule can be used to make certain adjustments to the peripheral circuits. The AC-DC conduction test is taken as an example.
As can be seen from the figure, the limits of the conductivity test for Class 1 products (herein referred to as: CLASS B) are required to be 10 dB lower than Class 2 products (CLASS A). If the power supply used by the product is a low-power AC-DC module with only one-stage filtering inside, it is usually no problem after CLASS A. If it is used in the 2 types of products, it can be considered according to the comprehensive test situation, without adding some filtering. The device thus saves a certain cost.
The peripheral design of EMS is basically the same as EMI. Take the surge as an example, generally class 1 commercial equipment or electrical appliances, anti-surge device varistor only need to choose 471KD07 (varistor voltage is 470V, maximum impulse current is 1200A, different manufacturers parameters will be different) is enough If used in an industrial environment with a very complicated environment (large relays in the vicinity, the motor works), it is necessary to use a pressure sensitive device 471KD10 (or 471KD14) that can withstand larger pulse currents. For the peripheral design circuit, please refer to Application Circuit 2 on our power supply manual.
Therefore, according to different products in different applications, the field data and experience can be used, and the protective device can be used just right, which can meet the EMC requirements of the product and reduce the cost.
banknote deposit module coin deposit module support OEM
Suzhou Ribao Technology Co. Ltd. , https://www.ribaoeurope.com