Why don t plugs have positive and negative poles, and why household sockets don t have positive and

It doesn't matter if the positive and negative poles don't matter, so naturally there is no need to divide them.

There are two wires for alternating current (referring to household two-phase alternating current), one is called the neutral line and the other is called the live wire, the potential of the neutral line is unchanged, which is equal to the electric potential of the earth, so you will not be electrocuted if you touch that one.

Many people can't understand it clearly, thinking that since one is charged and the other is not, it should be like a battery, flowing from the charged (live wire) to no or vice versa, how can it be called alternating current?

In fact, the range of potential change of the live wire is positive and negative alternately relative to the zero electric potential (waterline) (taking any direction as positive, this statement is not correct, but it is easy to understand), so sometimes 0 is less than the positive potential, sometimes 0 is greater than the negative potential, so the current direction changes alternately.

Suppose you plug in the plug at the same time, but the direction is reversed, and the only change is the phase of the current.

Because the plug is generally used for AC appliances, even if the appliance itself uses direct current, then it must have an AC to DC converter inside, so the plug part does not need to be divided into positive and negative poles.

Because household electricity is alternating current. The direction of the current of alternating current will change.

Household appliances use 220V (sinusoidal) alternating current!

There is no positive or negative direct current.

The plug can also be plugged into the DC power supply

Because the wiring in the plug is symmetrical, the positive and negative poles only need to look at the positive and negative of the power supply.

Because it is plugged in with mains, 220V AC, if it is connected to a 220V DC point, it will be divided.

There is only the zero line of fire, there is no positive or negative.

There is no need to divide alternating current...

Because the power consumption of the socket is alternating current, the voltage direction in the line is changed, about 100 times per second (50Hz), and the positive and negative electrodes are constantly changing, so the positive and negative electrodes cannot be determined.

The battery is divided into positive and negative poles because its current is direct current, and the positive and negative electrodes are constant. Positive and negative electrodes: It is formed due to the potential difference (voltage) between two points, the end with the high potential of the electric disturbance is the positive electrode, and the low electric potential is the negative end.

Direct current: The current direction is in one direction and does not change. Alternating current: The direction of the current is uncertain.

Hello dear! Cavity orange hungry glad for your question! How to distinguish the positive and negative poles of the plug:

There is no positive or negative in alternating current, and n and l are the meaning of live wire and neutral wire. The neutral line is the line drawn from the neutral point (n) on the secondary side of the generator or variable voltage back pressurer, and forms a circuit with the phase line (l) to supply power to the electrical equipment. Under normal circumstances, the neutral line is repeatedly grounded (PEN) with the protective ground wire (PE) at the neutral point (N) on the secondary side of the transformer, which plays a double protection role.

Live wire refers to a wire that connects to the positive pole in a DC circuit.

Hello, I'm glad to answer for you, only the positive and negative poles how to connect the three socket heads? The three-hole socket has a binding post that is the grounding wire, if it is an ordinary wire with only two wires, as long as it is connected to the live wire of the socket and the simple binding post of the neutral wire, the grounding wire is vacant. One of the three-hole sockets is connected to the ground wire, and now many families do not put the ground wire when decorating, only zero live wire, which does not affect the electricity consumption, but there are all hidden dangers of talking about closed pants.

The three-pin socket has a grounding wire in the house, and the electrical equipment leaks electricity and personnel. Above the three-hole socket is the grounding wire, and the two-state guess root of the general wire is connected to the left zero wire and the right live wire. The three-pin socket also stores ground wires in addition to the positive and negative poles.

There is also a grounding wire that acts as a protective effect. I hope mine can help you, if you are satisfied with my service, please give a thumbs up, I wish you all the best!

In fact, it is divided, according to the standard, the correct wiring of the ordinary wall plug in the household should be "left zero right fire", as shown in the figure below.

Of course, in fact, there are many cases of reverse connection, but there is no situation where the appliance does not work. This is because even if the voltage is reversed, the voltage does not change, so it can still work normally. The explanation is as follows.

It can be seen that even if the connection is reversed, the voltage difference is still the same, but the phase changes, which has no effect on ordinary electrical appliances at all.

In particular, many electrical appliances actually turn alternating current into direct current for internal use, and there is no effect in this case.

However, it is still recommended that the zero fire should be connected, otherwise there are still some potential risks. For example, the zero wire is connected to the switch, causing the electrical appliance to still be charged after the switch is turned off; The live wire is connected to the thread of the lamp head, which is more likely to cause electric shock and so on.

In particular, you must not confuse the ground wire with the zero live wire, and if the ground wire is connected incorrectly, it will be more dangerous.

Ask the right person, in fact, when I was seven years old, I thought that the neighbor's fire was plugged in anyway and the negative pole was wrong, and then I found someone to say it everywhere, now I think about it is full of sourness, to get back to the point, this is because the household power supply, that is, the household appliances actually use alternating current, that is to say, the live wire has electricity, the zero line has no electricity, the live wire is electrified but the positive and negative electrodes fluctuate back and forth fifty times per second, which is also the origin of 50Hz, as for the 220V voltage, it is actually because the positive and negative electrodes fluctuate back and forth The equivalent voltage is calculated, In fact, this voltage fluctuation to the peak and trough is higher than plus or minus 220V, so the problem is, when the power is turned on, the current direction of the entire circuit also changes back and forth with the alternating current, do you think there is any point in considering the current direction at this time, what is the positive and negative electrodes and what does it matter, even if there is a filter unit (that is, the circuit that integrates the positive and negative electrodes into an electrode) is also the same regardless of the neutral live wire end, that is, Regardless of whether this appliance directly uses alternating current or needs to be filtered to direct current and then used, in fact, the zero live wire is arbitrary. Of course, for the sake of safety, the home socket is the default power connection standard of the left zero and right fire, this is because the electrical appliances have switches, the simple structure of the switch is the default off of the live wire, the switch is off, the electrical appliances are not electrified, but after the reverse plugging, the switch is turned off is only the zero line, at this time do not unplug the power of the electrical appliances are still live, however, the electrical power of the two sockets is usually not large, the possibility of the shell running power is small, there is a demand will be specially designed as a zero-fire double-break switch, and the three-socket plug with a high-power grounding line can not be reversed in most cases, And as long as the grounding wire is connected, the shell will be grounded when it is live, forming a double insurance, and some are even zero-fire double-broken three-insurance design, as for the plug you said is not divided into positive and negative poles, in fact, it is not only the positive and negative connections that I explained above are positive and negative poles back and forth become a problem, or a practical problem, because there is no brain-dead designer who designed an artifact that does not work if the electrical plug is reversed. Therefore, household appliances are basically not divided into positive and negative poles, and it is mandatory to require the zero line of the live wire to be very rare, which is also one of the practicality of AC, in fact, after the application of electric energy at the beginning, the dispute about DC AC exists, Edison advocated low-voltage DC transmission, the reason is that it is safe and the electrical structure is simpler, Tesla advocates high-voltage AC transmission, the reason is to save transmission costs, and finally the AC scheme wins, it turns out that in addition to the poor safety is almost all advantages, not only that, The efficiency ratio of the alternator itself is also higher than that of the DC generator.

The mains power in China is alternating current, with an equivalent voltage of 220V (volts) and a frequency of 50h medium (Hz).

Since it is alternating current, there is no positive and negative electrode, because it is the positive and negative electrodes that should be constantly exchanged, so it is called alternating current. In other words, there will be a positive pole and a negative electrode on both lines (but not at the same time).

Televisions, computers and other electrical appliances have rectifiers inside, which converts alternating current into direct current, which is used by the internal circuit of the power supply. Therefore, this type of electrical appliance does not need to distinguish between positive and negative poles.

Incandescent lamps, electric kettles, rice cookers and other electrical appliances use the thermal effect of electric current, mainly through the current through, no matter what the direction, will be heated, so this kind of electrical appliances do not need to distinguish between positive and negative electrodes (some electric kettles, rice cookers, etc. with microcomputers use direct current, and there are also rectifiers inside).

AC motor, AC motor itself is the use of AC positive and negative pole transformation to generate a transformed magnetic field, so AC motor does not need to distinguish between positive and negative poles.

There is no positive or negative pole on the AC line, but there is an important differenceLive and neutralIn fact, as far as the power supply of alternating current is concerned, there is no difference between the live wire and the neutral wire, both are the same. The live wire and neutral wire are for circuit transmission and electrical appliances. In the process of power transmission, one of the lines of the power supply of alternating current is connected to the earth, and this line is calledZero line, the earth is a conductor, so the voltage between the neutral line and the earth is 0v,Therefore, if you touch the zero line, you will not be electrocuted

The voltage between the live wire and the neutral wire is 220V, so the voltage between the live wire and the ground is also 220VTherefore, if you touch the line of fire while standing on the ground, you will be electrocuted.

Plugs are generally used for AC appliances. 220V alternating current, also known as sine wave alternating current, its polarity is sinusoidal change, and the positive and negative poles are also changing, so there is no problem of plugging back.

In Japanese power sockets, the left and right holes are of different sizes, and if they are reversed, they cannot be plugged in. This is a sign of the rigor of the Japanese people.

Generally, household appliances are directly connected to the mains 220V, because our mains is AC. Alternating current is not divided into positive and negative poles, only the neutral wire or live wire, so the plug of household appliances is not divided into positive and negative poles.

Further reading: DC power is divided into positive and negative poles, for example: the mobile phone charger we usually use can be directly connected to 220V AC power.

Convert 5V or 9V DC power to charge the mobile phone through the charger, and some fast charging equipment needs 12V DC power, and this low voltage is divided into positive and negative poles. For example, we usually use dry batteries. The output is also direct current.

Or lithium batteries are also direct current. These are both positive and negative.

If you don't understand, you can ask, pure manual typing, thank you for adopting!

Because the electricity consumption of household appliances is alternating current, that is, the potential (relative voltage value) on each plug pin is in a positive and negative change of 50 times per second, so there is no positive and negative pole for alternating current, and the plug of household appliances is not divided into positive and negative poles.

Household appliances generally have many three-pin plugs.

The main function is the safe use of positive and negative electrodes and neutral lines.

The household mains is single-phase alternating current, with a frequency of 50 Hz per second, and there are 25 half-cycle currents flowing from the live wire to the neutral line, and 25 half-cycle currents flowing from the neutral line to the live wire, how do you define their positive and negative poles? The concept of positive and negative electrodes only exists in DC systems, because the current always flows from the positive to the negative.

The plugs of household appliances are connected to the 220 socket, so that the plug is divided into live wire and neutral wire, not positive and negative poles. If the appliance is a double-open switch, then there is no point in splitting the fire and zero; If the appliance housing is insulated, then there is no need for the plug to divide the fire and zero, so the plug does not divide the fire and zero either. There is only a metal shell, and in order to ensure that the internal switch can reliably control the live wire, a three-phase plug is adopted to ensure that the live wire is controlled by the switch.

Low-power appliances are usually two-pin plugs, because most of these appliances have plastic shells, and the power supply is also very low, so there will be no electric shock accidents.

Usually only electrical appliances with high power or if an electric shock accident occurs are used three-core plug with ground wire, and the shell is usually also a metal shell used, which communicates with the ground wire.

Because most of the household appliances are alternating current, alternating current is only divided into zero live wires, regardless of positive and negative. Only direct current, such as batteries, batteries, etc., are divided into positive and negative poles.

Why is the plug of a household appliance not divided into positive and negative poles - because there is no positive and negative electrode for alternating current, only zero live wire

Divided, the national norm stipulates: if the plug of the two claws is inserted into the socket, the left zero and the right fire. If the hole is above and below is on the fire, down to zero. The plug of the three claws is inserted into the socket, the left zero and right fire, and the PB wire (ground wire) of the upper claw is inserted