It is composed of switching voltage and switching off pulse width of modern FET. It is a kind of power supply control skill, which is composed of switching on and switching off pulse width of IC. With the development and innovation of power electronics skills, switching power supply skills are constantly innovating. Now, switching power supply is widely used in almost all electronic equipment with the characteristics of small size, light weight and high power. It is a power supply mode that is indispensable for the rapid development of electronic information industry.
Switching power supply is generally composed of pulse width modulation (PWM) control IC and MOSFET. Compared with linear power supply, the cost of switching power supply and linear power supply increases with the increase of output power, but their increase rates are different. The cost of linear power supply is higher than that of switching power supply at a certain output power point, which is called the cost turning point. With the development and innovation of power electronics skills, the skills of switching power supply are also constantly innovating. This cost turning point is increasingly moving to the low output power end, which provides a broad development space for switching power supply.
According to the statement on the research and development prospect of China's switching power supply market released by China Industrial Research Network, the high frequency of switching power supply is the direction of its development. The high frequency makes the switching power supply miniaturized and makes the switching power supply enter a wider range of use, especially in the field of high and new skills, which promotes the development of switching power supply, with an annual increase rate of more than two digits towards light, small, thin, low noise High reliability and anti disturbance. Switching power supplies can be divided into AC / DC and DC / DC. DC / DC converters have been modularized, and planning skills and production processes have been sophisticated and standardized at home and abroad.
Prospect of switching power supply in the 21st century: 1.1 Semiconductor and circuit equipment are important supports for the development of switching power supply. 2 The development direction of power electronic products or circuits is modularization and integration Special chips with various control functions, external wiring and solder joints are reduced, and the reliability is significantly improved Integration and modularization make the power supply products small in size and high in reliability, which brings great convenience to use It can be predicted that the following issues are the eternal direction of the development of switching power supply:
(1) The frequency of switching power supply should be high, so that the dynamic response can be fast. It is necessary to cooperate with high-speed microprocessor operation; It is also an important way to reduce the volume
(2) The volume should be reduced, and the inductance and capacitance of the transformer should be reduced
(3) The power should be high, the generated heat energy will be reduced, the heat dissipation will be simple, and the high power density will be achieved
Power electronics technology is an important supporting technology. According to the president's Advisory Committee on science and technology, there are seven key national science and technology areas: power, environmental protection, information and communication, life science, data and transportation Every category is related to power electronics and plays an important role. Switching power supply is an important aspect of it. It has far-reaching and bright prospects. It is very important to choose a good and high-quality manufacturer. The problem of after-sales is also a concern of our customers, and quality assurance is particularly important. In this regard, Shenzhen sikat Electric Co., Ltd. has undoubtedly done very well, with sufficient power, low temperature rise and perfect after-sales, The delivery time is short, the local old brand enterprises in Shenzhen have many kinds of products, the quality is stable, the good faith management does not falsely mark the power of the power supply, the starting quantity is sensitive, the delivery time is sensitive, and the after-sales service is guaranteed. The manufacturers with quality problems are responsible for it, and the warranty is two years.
The linear power supply generally samples the output voltage and then sends it to the comparison voltage amplifier with the reference voltage. The output of the voltage amplifier is used as the input of the voltage regulation tube to control the regulation tube so that its junction voltage changes with the change of the input, so as to adjust its output voltage. However, the power supply is switched on and off by changing the on and off time of the regulation tube, that is, changing the duty cycle to change the output voltage!
From its main characteristics: the linear power supply has sophisticated skills, low manufacturing cost, high safety and stability, small ripple and low disturbance and noise. However, because the operation is at power frequency (50Hz), the transformer has large volume and low power (generally, the power of full load operation is only about 80%), the whole volume is large and bulky And the input voltage range is required to be high; The switching power supply is the high-frequency condition of operation. The volume of the transformer is relatively small and relatively simple, but the output ripple is larger than that of the linear power supply. However, due to its simple structure, low cost and high power (the power of the switching power supply on the market can also reach more than 90%), it has replaced the linear power supply in many occasions, which is the trend of power supply development in the future.
