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How to choose a switching power adapter
Sep 25, 2018

    As the heart of electronic equipment, switching power supply plays a vital role in the safe and reliable operation of electronic equipment. Therefore, the power supply should be selected during the system development phase of the electronic device, rather than selecting the power supply when the design of the entire system is completed. Otherwise, the development time of the system and the cost of the system are often delayed.


    The main issues to consider when choosing a switching power supply are:


    According to the use situation, determine the required output voltage, current; power supply size, installation method and installation hole position; there are several outputs, each output needs electrical isolation; input voltage range; according to the ambient temperature, determine the switching power supply drop Amount, power supply; whether certification and safety standards are required; cooling method of power supply: natural cooling or forced air cooling; electromagnetic compatibility standard.


    In order to improve the reliability of the system, it is recommended that the switching power supply work at 50%-80% load, that is, assuming that the power used is 20W, a switching power supply with an output power of 25W-40W should be selected.


    Try to use the standard power supply of the switching power supply manufacturer, including the standard size and output voltage. This will result in faster delivery; on the contrary, special size and output voltage will increase development time and cost.


    Clear input voltage range, taking AC input as an example, the commonly used input voltage specifications are 110V, 220V, so there are 110V, 220V AC switching, and universal input voltage (AC: 85V-264V) three specifications. The input voltage specification should be selected according to the region of use.


    The switching power supply consumes a part of the power during operation and is released in the form of heat. Therefore, the user should consider the heat dissipation problem of the switching power supply in the system design (especially the closed system).


    There is also a special case, such as: output with motor, printer, light bulb, large relay and other impact negative load, the instantaneous current is very large, it is best to provide the maximum load current, so that we can design specifically; the system is used for lightning multiple When using lightning protection in the lightning sensitive location such as the top of the mountain, it is better to choose a switching power supply with lightning protection to ensure the safe operation of the system equipment.


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