When decorating and designing cables, you also need to pay attention to the choice of the main power switch. After all, there are many main power switches, and they are matched to different voltage ranges and output powers. load characteristics, etc. The following is how to choose the working mode of switching power supply and switching power supply. In the process of choosing a switching power supply, we can pay attention to those problems, and then try to choose the announced switching power supply products, and the application effect will be much better.
How to choose a switching power supply.
When choosing a switching power supply, the input voltage range, moderate output power, load characteristics, and operating temperature should be considered.
1. Select the appropriate input voltage range. Take communication typing as an example. Common input voltage specifications are 110V and 220V, so there are 110V.220V AC conversion and general input voltage (AC: 85V-2**V). The input voltage specification model should be selected according to the application area.
2. Select the appropriate output power. The switching power supply consumes part of the output power during operation and releases it as heat energy. In order to better increase the service life of the switching power supply, it is proposed to select equipment with a rated power exceeding 30%.
3. Consider the load characteristics. In order to better improve the stability of the operating system, it is proposed to switch the power supply in operation under a load of 50%-80%, that is, assuming that the common output power is 20W, a switching power supply with a power of 25W-40W should be selected.
If the load is a motor, light bulb or capacitor load, the current is relatively large when starting, and a suitable switching power supply should be selected to prevent the load. If the load is a motor, the voltage reversal at shutdown should be considered.
4. In addition, the operating temperature of the switching power supply and whether there is excess auxiliary cooling equipment should also be considered. The temperature sensing switching power supply with too high a must reduce the output. Please refer to the reduction curve of temperature sensing power.
What is the working mode of the switching power supply?
Frequency. Pulse width fixed mode, frequency fixed. Pulse width variable mode, frequency. Pulse width variable mode.
1. The former working mode is mainly used in DC/AC variable frequency power supply or DC/DC voltage conversion; the latter two working modes are mainly used in switching regulated power supply.
2. In addition, the output voltage of the switching power supply also has three working modes: the immediate output voltage method, the average output voltage method, and the amplitude value output voltage method.
3. In the same way, the former working method is mainly used in DC/AC variable frequency power supply or DC/DC voltage conversion; the latter two working methods are mainly used in switching regulated power supply.
According to the interface mode of the switch cabinet in the control circuit, the switching power supply can generally be divided into three types: series switching power supply, parallel switching power supply, and transformer switching power supply. Among them, the transformer switching power supply (hereinafter referred to as the transformer switching power supply) can also be further divided into: sliding door type, semi-flat arm, full bridge type, etc.; according to the encouragement of the power transformer and the phase difference of the output voltage, it can be divided into: forward excitation, reverse Excited, single-excited, double-excited; if the main purpose is divided into a large number of types.
The above details are how to select the working mode of switching power supply and switching power supply. When choosing the main power switch, you need to clearly see the voltage standard and reasonable output power. If the voltage is relatively high, you should also master the load capacity of this material. In addition, in fact, the power switch has a variety of working modes, including fixed frequency, pulse width, etc., so it should be selected according to the scope of application in the home.
Post time: Apr-25-2022