What are the differences between chargers of different sizes?

"Chargers come in different sizes. Are there any essential differences? What does 5V2a mean?"

In fact, except for some fake phones, the chargers that come with genuine mobile phones are not very different in nature. Of course, generally speaking, the heavier and larger the charger, the more electronic components it contains. It can be understood that the heavier the charger, the better the quality. Of course, this is just a general statement, not an absolute argument. So what are the specific differences? I will take this opportunity to explain the differences between chargers.

What is the difference between chargers?

In fact, the common specifications of mobile phone chargers on the market are: 5V-0.5A, 5V-1A, 5V-1.5A, 5V-2A, 5V-2.5A, and the most widely used ones on the market nowadays are basically 5V-2A.

Briefly explain the meaning of the numbers on mobile phone chargers:

First of all, the current national unified rated voltage is 220V. The mobile phone charger is equivalent to a small transformer. The mobile phone charger converts the 220V high-voltage pulse into a 5V low-voltage pulse, and then directly converts it into 5V direct current through the charger's conversion and voltage stabilization, which is the "constant voltage" effect. 2A means the highest load power, which is the "constant current" effect.

If the load of the mobile phone is a 10 ohm resistor, then the output current should be I=U/R=5/10=0.5A, and if the load of the mobile phone is a 1 ohm resistor, then the output current should be I=U/R=5/1=5A, and the maximum capacity of your charger is 2A, then it will be overloaded. "Constant voltage" and "constant current" can actually be simply understood as "voltage limiting" and "current limiting". Voltage refers to the conversion voltage of 5V, and current refers to the output current of 2A.

It's like a car can run up to 300km, but in actual use, first see if the road can allow you to reach 300, and secondly whether there is a traffic jam ahead that allows you to reach that speed. In fact, general charging power supplies will have a margin. Taking 5V-2A as an example, the maximum margin of this power adapter may be 2.4A. When the mobile phone is charged when there is no power, the output of this power supply may reach 2.4A, but if it is higher, it will cause the power adapter to burn to protect the charging device. When the charging device is gradually fully charged, the output current will slowly decrease.

Here are two more words:

When the mobile phone charger is plugged in but not charging, no current will be generated. Netizens do not need to worry about problems such as electric shock when using it. The reason is that when the load is infinitely small and the resistance is infinitely large, the current I=U/R=5/∞=0A, that is, no current will appear, and there is no need to worry about electric shock.

Generally speaking, the function of mobile phone chargers is to convert high-voltage AC into low-voltage DC. The overall difference is not big, the difference is the maximum output current. The speed of charging of some mobile phones depends on the fast charging technology inside the mobile phone and the cooperation of the original power supply. When an unsuitable power supply is used to charge another mobile phone, it may cause slow charging due to high or low rated output, and the mobile phone cannot recognize the connected power of the charger and cannot start the fast charging mode.

As a winner of Toutiao's Qingyun Plan and Baijiahao's Bai+ Plan, the 2019 Baidu Digital Author of the Year, the Baijiahao's Most Popular Author in the Technology Field, the 2019 Sogou Technology and Culture Author, and the 2021 Baijiahao Quarterly Influential Creator, he has won many awards, including the 2013 Sohu Best Industry Media Person, the 2015 China New Media Entrepreneurship Competition Beijing Third Place, the 2015 Guangmang Experience Award, the 2015 China New Media Entrepreneurship Competition Finals Third Place, and the 2018 Baidu Dynamic Annual Powerful Celebrity.