Analysis of the advantages of common power adapters, do you understand?

“In life, you may have come into contact with various Electronic products, then you may not know some of its components, such as the power adapter it may contain, then let Xiaobian lead you to learn about the power adapter.

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In life, you may have come into contact with various Electronic products, then you may not know some of its components, such as the power adapter it may contain, then let Xiaobian lead you to learn about the power adapter.

Regarding the power adapter, all kinds of electrical appliances have applications in our lives. This is a facility that can provide voltage conversion for electronic appliances and portable electronic equipment. It can convert the high voltage of 220 volts in the home into general electronic products. A stable low voltage is required so that electronic products can work normally.

Advantages of Power Adapters

1. Small size and light weight. Switching power adapters do not use bulky power frequency transformers. Since the dissipated power on the switch MOS tube is greatly reduced, a larger heat sink is omitted. Due to these two reasons, the switching power adapter is small in size and light in weight.

The switching tube works in the switching state, the power loss is small, the efficiency can be as high as 80% to 90%, and the efficiency of the good quality can reach 95% or even higher, while the efficiency of the linear power supply is only 50% or even lower

2. Low power consumption and high efficiency. In the switching power supply adapter Circuit, the switching MOS tube works alternately in the on-off and off-on switching states under the excitation of the excitation signal. The conversion speed is very fast, and the frequency is generally above 50kHz. In some advanced switches In the power supply line, several hundred or nearly megahertz can be achieved. This makes the power consumption of the switch MOS tube very small, and the efficiency of the power supply can be greatly improved, and its efficiency can reach 90%.

The switch tube works in a high frequency state, and only a small transformer is needed to transmit a large amount of energy; the loss of the switch tube is small, and the radiator is also reduced or not used at all; the switching frequency is above tens of kilohertz, which is linear 1000 times the power supply, the filtering efficiency after rectification is almost 1000 times higher, so the capacity and volume of the filter Inductor and capacitor are greatly reduced; at the same time, the allowable ambient temperature is also greatly improved

3. The efficiency of filtering is greatly improved, which greatly reduces the capacity and volume of the filtering capacitor. The operating frequency of the switching power adapter is basically above 50kHz, which is more than 1000 times that of the linear regulated power adapter, which makes the filtering efficiency after rectification almost 1000 times higher; Efficiency is also increased by a factor of 500. Under the same ripple output voltage, when the switching power supply is used, the capacity of the filter capacitor is only 1/500 ~ 1/1000 of the filter capacitor in the linear regulated power supply.

When the input voltage or load changes cause the output voltage to fluctuate, the power adapter can adjust the pulse width, pulse frequency or both at the same time. In the case of large changes in the grid voltage, the power adapter can still ensure a stable output voltage.Therefore, the power adapter has a wide range of voltage regulation, good voltage regulation effect and a wide range of applications.

4. Wide range of voltage regulation. The output voltage of the switching power adapter is regulated by the duty cycle of the excitation signal, and the change of the input signal voltage can be compensated by frequency modulation or width modulation. In this way, when the power frequency grid voltage changes greatly, it can still ensure a relatively stable output voltage. Therefore, the voltage regulation range of the switching power adapter is very wide, and the voltage regulation effect is very good. In addition, there are two methods of changing the duty ratio: a pulse width modulation type and a frequency modulation type. Switching regulated power supply not only has the advantages of wide voltage regulation range, but also has many methods to achieve voltage regulation. Designers can flexibly select various types of switching power supply integrated circuit chip solutions according to the requirements of practical applications.

Power adapters include self-excited and other-excited, width-modulated and frequency-modulated, isolated and non-isolated.