Nowadays, you are more or less exposed to switching power supplies in your work and life, but there are many types of switching power supplies and different types of switching power supplies have different parameters such as voltage, current, power, and load characteristics. Dazzling, you don’t know how to choose the switching power supply. The following introduces some selection skills so that you can avoid detours in the process of selecting a switching power supply, and then choose regular switching power supply products as much as possible so that the effect of use will be much better.
The first point of choosing a switching power supply is to clarify your needs
Under normal circumstances, you only think about buying a switching power supply when the products you use fail. You can directly take the previous power supply and find some companies that specialize in selling switching power supplies. Is there any model or parameter that matches it? The models that can be replaced can be carried out in the following aspects:
1. Input and output types of switching power supply
Can be roughly divided into: ①AC/DC ②DC/DC ③DC/AC
Note: AC means alternating current, DC means direct current, such as AC/DC means AC input and DC output.
2. Input voltage
Commonly used input voltage specifications include 110V, 220V, and universal input voltage (AC: 85V-264V). The input voltage specification should be selected according to the area of use.
3. Output voltage, current
To choose a switching power supply, the voltage should be the same first, and the current should be the second. The rated current of the switching power supply must be greater than the maximum current of the load. For example, if your circuit is 15V, or 60mA, it is generally recommended to choose a power supply above 100mA. In addition, as long as the voltage is the same, no matter how much current the switching power supply provides is larger than the actual use, only so much will pass through the circuit, and there will be no damage.
4. Switching the power supply function
① Regulated switching power supply: the input voltage and output voltage are rated at a certain value;
②Thyristor switching power supply: the output voltage can be changed by adjusting the input voltage;
③Adjustable switching power supply: within the rated range of the input voltage, the output voltage and current can be adjusted by means of potentiometers, etc.
5. Switching power supply load characteristics
In order to improve the reliability of the system, it is recommended that the switching power supply work at a load of 50%-80%, that is, choose a model with an output power rating of about 30%. For example, if the power used is 20W, a switching power supply with an output power of 25W-40W should be selected. If the load is a motor, a light bulb, or a capacitive load, the current will be relatively large when the power is turned on, and an appropriate power supply should be selected to avoid overload.
6. Ambient temperature
It is also necessary to consider the working environment temperature of the switching power supply, whether there is an additional auxiliary heat dissipation device, and whether the output of the power supply needs to be derated if the ambient temperature is too high. Refer to the derating curve of ambient temperature versus output power.
Select the second point of switching power supply, choose the right brand
There are many brands of switching power supplies, and their service life is relatively long, and the frequency and time of use are relatively long. If the quality of switching power supplies is not high, problems are likely to occur. I believe that everyone is more willing to buy high-quality products. Although the price of switching power supplies on the market is different, if some non-professionals want to compare the advantages of products Inferiority is still difficult, so brand products must be selected. The products of big brands or big manufacturers have been tested by authoritative departments, and the quality of their products is better. Although the unit price is slightly higher, there will not be much difference in price, which is more suitable for us to choose.
Select the third point of switching power supply to determine the after-sales service
The switching power supply can basically be used for several years. Of course, this is only on the basis of the purchased product being a regular product to ensure a long service life. When purchasing, you must confirm with the seller. If there is a problem within one month of use, then the other party will also provide an unconditional replacement or help us with repairs. It is not recommended to choose non-brand three-no products. The quality of such products is likely to have problems, and may even threaten our safety, and the products of merchants that can provide better after-sales service also have better quality assurance.
