Switch power adapter explanation

The Switching Power Supply adapter is composed of a full-wave rectifier, a switch tube, an excitation signal, a diode, an energy storage inductor and a filter capacitor. In fact, the core of a switching power adapter is a dc-dc converter. Here we explain the dc converter and inverter as follows. An inverter, which converts direct current into ac. Inverters are widely used in standby power supplies that use electrical levels or batteries. A dc - dc converter is a device that converts dc first into ac and then from ac to dc. This device is widely used in switching Power Supply. A dc supply voltage can be converted into a variety of dc supply voltages with different polarity and value by using a dc - dc converter.

1.Summarize
The switching power adapter is a power supply converter for small portable electronic equipment and electrical appliances.

2.Constitute
The switching power adapter generally consists of a housing, a switch, a power transformer and a rectifier circuit.

3. Classification
According to its output type, the switching power adapter can be divided into ac output type and dc output type. According to the connection can be divided into plug wall type and desktop type.

4. Application
The switch power adapter is widely used in the telephone submachine, the game machine, the language repeater, the walkman, the notebook computer, the cellular phone and so on.

5. Advantages
The switch power adapter has the advantages of small appearance, easy to carry, wide variety of USES, suitable for various environments, reliable quality and so on.

(1)Small in size and light in weight.

The switching power adapter does not use a bulky power-frequency transformer. Since the dissipated power on the switch MOS tube is greatly reduced, a larger radiator fin is saved. Because of these two reasons, the switching power adapter is small in size and light in weight.

(2) Low power consumption and high efficiency.

In the switching power adapter circuit, the switching MOS tube is excited by the excitation signal, and it works alternately in the on-off and on-off switching states. The conversion speed is very fast, and the frequency is generally more than 50kHz. In some advanced switching power supply lines, it can be achieved at several hundred or nearly 1 gigahertz. 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%.

(3) The efficiency of filtering is greatly improved, and the capacity and volume of filtering capacitor are greatly reduced.

At present, the working frequency of the switching power supply adapter is basically above 50kHz, which is more than 1000 times that of the linear stabilized power supply adapter. This makes the filtering efficiency after rectification almost increase by 1000 times. The efficiency is increased by 500 times even after half wave rectification and capacitor filtering. At the same ripple output voltage, when using a switching power supply, the capacity of the filter capacitor is only 1/500 ~ 1/1000 of the filter capacitor in the linear stabilized power supply.

(4) Wide range of voltage stabilization.

The output voltage of the switching power adapter is regulated by the duty cycle of the excitation signal, and the variation of the input signal voltage can be compensated by frequency modulation or width modulation. In this way, it can still guarantee a stable output voltage when the power network voltage changes greatly. Therefore, the voltage stabilizing range of the switching power adapter is very wide and the voltage stabilizing effect is very good. In addition, there are two ways to change duty cycle: pulse width modulation and frequency modulation. Switching stabilized power supply not only has the advantages of a wide range of stabilized voltage, but also has many methods to achieve voltage stabilization. Designers can flexibly choose various types of switching power supply integrated circuit chip schemes according to the requirements of practical applications.

Best Regards,

Ada Zheng