Why is AC / DC conversion required?
As we all know, the main
Power Supply of Japanese homes or buildings is AC100V or 200V. However, most of the electrical appliances are operated through the electronic circuits, almost all of which use 5V and 3.3vdc voltage. Although there are motor equipment, incandescent lamp and other equipment directly driven by AC voltage, but the near motor and switch and other relatively simple equipment are almost inevitably equipped with electronic control circuits, and all electronic control circuits are driven by DC voltage. In addition, the market gradually changes incandescent lamp into led just as we all know, LED is still driven by DC basically, that is to say, the AC delivered from the power grid is equivalent to the electronic circuit of the heart of electronic products, so if the AC voltage is not converted into DC voltage, the electronic products cannot be started. ".
In 1881, Edison invented the electric lamp with incandescent bulb. In fact, in the United States at that time, Edison began to implement the cause of dc110v power grid in order to promote incandescent bulb, with the supply of DC
Power Adapter as the standard. However, when transmitting DC power, the voltage will be greatly reduced, so the transmission range cannot exceed 1.5km, so the power plant must be built in the street. It's unbelievable now. Nikolai Tesla inspected AC power generation, power transmission, use methods, and Edison started a current war. After Tesla's side to be able to easily variable voltage, and even if the wire is thin and long, the transmission of power will not cause too much loss of AC system to win, and the result has continued to this day.
As long as the AC power supply uses a transformer, it can easily convert the voltage (step-up, step-down)
High voltage / low current can be maintained during power transmission to reduce voltage drop (I2R loss)
It can easily convert AC power into DC power and supply power DC drive equipment.
In fact, the power plant sends thousands to 20000 VAC of high voltage, before it is sent to the general household, and then through the transformer on the pole, the voltage is reduced to 100V and 200V
AC/ DC conversion is to directly convert the input AC voltage into DC after rectifying smoothing, then convert the DC into high frequency AC and then repeat the rectifying smoothing method to convert the desired DC voltage. Compared with the previous transformer mode, it is very complex to repeat AC / DC conversion twice. In recent years, the use of switch mode AC / DC
Converter is increasing.
