What is the direct current, alternating current (ac) is what?

Electricity is part of the production and living, can say is the, how much do you know knowledge of electric, dc and ac? Direct current (dc), refers to the current direction does not change over time. Alternating current (ac), refers to the size and direction of cyclical changes in current. A, the electric power is a natural phenomenon. Static or moving electric charge will produce a lot of interesting physical phenomena, such as thunderstorm weather will see lightning sparks of villager, take off your sweater in the winter. Later, scientists found in all kinds of electric effect rule, and invented the battery, generator, electric motor. With direct current (dc), or with alternating current (ac) first? 220 v / 50 hz alternating current (ac) is the standard of power supply in our country, so a lot of people think is alternating current (ac) for household appliances. As for the direct current (dc), except perhaps will say that the advertisement & other; Dc frequency conversion air conditioning & throughout; , the other can not think of it. Second, the alternating current, direct current (dc), who is better? With the constant improvement line voltage, power and transportation distance increasing, direct current (dc) and get the favour of engineers. Because there is no phase difference, dc doesn't need rectifier filter, stable. How to boost dc? Short, booster job to do communication, ac/dc conversion once again ok ~ and, from the economic point of view, although the dc converter station is higher than ac power substation cost, but the dc line as long as the positive and negative two lines, communication lines three-phase need three lines, dc lines cost is lower, so the longer the distance, the more suitable for dc transmission. Three, that why change alternating current (ac) to direct current? In fact, it is widely used direct current (dc), you must have seen, is also used. 1, have you ever wondered why mobile phone plug is larger than general plug? In fact, strictly speaking, this & other; The plug & throughout; Call switching power adapter, the purpose is to alternating current into direct current transmission grid came into electronic devices. Laptop power adapter is bigger, the winter warming my hands more convenient ~ 2, household electrical appliances why using a direct current (dc)? Back in the field of home appliances, IT products ( Such as mobile phone, computer) And most of the direct current (dc) should be used in home appliance inside. Because laptop computers and cell phones require deft, rectifier on the outside, and desktop computer, refrigerator, air conditioning and other put rectifier within the appliance. Why is that? Return to nature, direct current is a continuous flow from anode to cathode, alternating current (ac) is fluctuating. And electronic components is by identifying potential to work, such as computers, has a potential for 1, there is no potential for 0, alternating current (ac) itself will have zero potential, this electronic components cannot be properly logic judgment.