Switching power adapter is composed of full-wave rectifier, switch, excitation signal, freewheeling diode, energy storage inductance and filter capacitor. In fact, the core of the switching power adapter is the DC-DC converter. Here we explain the DC converter and the inverter as follows. Inverter, it is the DC into AC device. Inverters are often used extensively in standby power supplies with levels or batteries. DC-DC converter, which is the DC first converted into AC, and then turn the exchange into a DC device. This device is widely used in switching power supply. DC-DC converter can be used to convert a DC supply voltage into a variety of different DC power supply voltage.
1, Overview: Switching power adapter is a small portable electronic equipment and electrical and electronic power supply conversion equipment.
2, the composition: switching power adapter generally by the shell, switches, power transformers and rectifier circuit.
3, classification: switching power adapter according to its output type can be divided into AC output and DC output type; according to the connection can be divided into wall and desktop.
4, application: switching power adapter widely supporting the phone son machine, game consoles, language repeaters, Walkman, notebook computers, cellular phones and other equipment.
5, the advantages: switching power adapter has a small appearance, easy to carry, versatile and versatile for a variety of environments, such as the advantages of reliable quality.
1. Small size, light weight The switching power adapter does not use bulky frequency transformers. As the switch MOS tube on the power dissipation greatly reduced, but also eliminates the need for a larger heat sink. Because of these two reasons, so the switching power adapter is small, light weight.
2. Power consumption is small, high efficiency. Switching power supply circuit, the switch MOS tube excitation in the excitation signal, it alternately in the conduction - cut-off and cut-off switch state, the conversion speed is very fast, the frequency is generally above 50kHz, in some advanced switch Power lines, you can do hundreds or nearly trillion Hz. This makes the switch MOS tube power consumption is very small, the power efficiency can be greatly improved, the efficiency can reach 90%.
3. Filter efficiency greatly improved, so that the filter capacitor capacity and volume greatly reduced. Switching power adapter operating frequency is basically working above 50kHz, linear regulator power adapter is more than 1000 times, which makes the rectification of the filter efficiency is almost increased by 1000 times; even after the use of half-wave rectifier capacitor filter, Efficiency is also increased by 500 times. In the same ripple output voltage, the use of switching power supply, the filter capacitor capacity is only linear regulator power supply filter capacitor 1/500 ~ 1/1000.
4. Wide voltage range. The output voltage of the switching power adapter is adjusted by the duty cycle of the excitation signal. The change of the input signal voltage can be compensated by FM or wide adjustment. In this way, in the power grid voltage changes greatly, it can still ensure a more stable output voltage. So the switching power supply voltage regulator range is very wide, the regulator is very good. In addition, the method of changing the duty cycle is pulse width modulation type and frequency modulation type. Switching regulator power supply not only has the advantages of wide voltage range, but also to achieve more pressure methods, designers can be based on practical application requirements, the flexibility to use various types of switching power supply integrated circuit chip program.