Power adapter several common problems!

One, what is the meaning of the nominal voltage and current of the Power Adapter (hereinafter referred to as the power supply)?

First of all, the nominal voltage of the ordinary power supply refers to the open-circuit output voltage, that is, the voltage of the outside without any load, no current output, so it can also be understood that the voltage is the upper limit of the output voltage of the power supply.

On the power supply internal use of active voltage regulator components, even if the mains voltage is shaken, the output is a constant value, like the common small transformer on the market, such as the walkman power supply, if the mains shake, the output of the power supply will not shake.

Generally speaking, the real no-load voltage of the ordinary power adapter is not necessarily the nominal voltage complete divergence, because the characteristics of the electronic components can not be complete divergence, so there is a certain error, the smaller the error of the electronic components of the divergence request is higher, the cost of consumption is high, so the price is more expensive.

In addition to the nominal current value, no matter any power supply has a certain internal resistance, so when the power supply output current, it will produce internal voltage drop, resulting in two things, one is to generate heat, so the power supply will be hot, the other is to cause the output voltage reduction, equivalent to internal consumption.

Two, are the same nominal voltage of the power supply, the output current is different, can be used in the same book?

The power supply voltage is the same, the output current is different, can be used in the same book. The fundamental criterion is that the power supply with large nominal current can replace the power supply with small nominal current. It is estimated that some people will think that the power supply with large nominal current will burn out the book, because the current is high. In practice, the current depends on the load at the same voltage. Think of junior high school physics. When the book is running at high load, the current is larger. When the book enters standby, the current is smaller. The power supply with large nominal current has enough current margin. On the contrary, there is no problem with someone using 56w power instead of 72w. The reason is that usually the design of the power adapter has a certain margin, the load power is less than the power of the power supply, so this replacement is feasible in common use, but the remaining power margin of the power supply is very little. Once you have a lot of peripheral devices, such as two usb hard drives, Then the cpu runs at full speed, there is a base, above to a full speed drive to read disk, plus at the same time to charge the battery, estimate the risk, at any time to touch your power supply has been able to boil eggs. So it is best not to use a small current power supply instead of a large current power supply.

Three, the same machine, other people's power supply is warm, mine is always very hot, why?

Do not suspect that your power supply has problems, first look at your laptop is doing, like the above mentioned two USB hard drives, CPU running at full speed, hard drive rampant read and write, CD-ROM reading disk at full speed, while charging the battery, playing loud music, screen brightness, wireless card constantly detect signal, etc., good use of power management, It is important to adjust the working state of the paper according to the task.

Four, the nominal voltage of the power supply is much higher than my battery voltage, will not have an accident?

The first thing to know is that a power source powering a laptop is not the same as a battery powering a laptop.

Battery power supply battery output is pure DC, very clean, battery voltage is neither possible nor need to design high, lithium battery chemical characteristics resolution of a cell output voltage can only be about 3.6V, so many batteries are using three series, 10.8V has become a very popular battery voltage. Some batteries have a nominal value that is a little larger than an integral multiple of 3.6V, such as 3.7V or 11.2V, to maintain the battery.

The power supply situation is more complex, first of all, the need to participate in the voltage stop further stabilizing filtering, to ensure the stable work in the power supply performance is not very good, the voltage after the voltage distribution of two parts, one way to the work of the power supply, the other way to charge the battery, the local power supply to the same time as the battery power supply, And to charge the battery that local demand after the battery charging control circuit can be added to the cell, the control circuit can be very complex, so the power supply voltage must be greater than the voltage of the cell to have enough to supply to the charging control circuit units. The actual voltage applied to the cell is never the nominal voltage of your power supply.