Is the mobile phone charged by DC or AC?

The input current of mobile phone charger is alternating current, and the output current is DC after rectification by transformer. The current received by the mobile phone is instantaneous.

1. The current collected by the mobile phone charger is alternating current. The transformer on the mobile phone charger used to be alternating current, and the rectifier circuit converted it into direct current to charge the mobile phone, which is direct current. The symbol of DC is DC and the symbol of AC is AC. Mobile phone chargers are generally DC, while AC is mainly used for transmission.

2. The output current of the mobile phone charger is DC. For example, when the mobile phone charger is charging, the charging curve is from 0-500mA or 500mA-0mA. When the battery of the mobile phone is exhausted, charge it at the maximum current.

Slowly, when the battery is charged more and more, the current of the mobile phone charger is getting smaller and smaller. When the battery is fully charged, the charging current of the mobile phone charger is 0. This is determined by the current limiting circuit of the mobile phone charger.

Extended data

A good quality charger can distinguish lithium batteries from nickel-hydrogen batteries, and then determine the charging method. On the protection circuit board of the lithium battery, there is an integrated circuit for storing the characteristic data of the lithium battery. On the one hand, it allows the charger to identify lithium batteries and determine the charging modes of "constant current" and "constant voltage"; On the other hand, it also allows the mobile phone to identify the lithium battery to determine the discharge mode.

The charging method of Ni-MH battery adopts "constant current". Ni-MH battery itself is not afraid of overcharge. When the Ni-MH battery is overcharged, the reverse reaction will occur to prevent the voltage from rising excessively, thus making the battery slightly hot.

In addition, Ni-MH batteries are usually equipped with a thermistor to prevent the battery from being overcharged. The working voltage of most mobile phones is about 3.6V, so three Ni-MH batteries are needed. Generally, the overcharge of Ni-MH battery stops when it reaches 1.4 ~ 1.5V, and the highest voltage of three batteries is about 4.4V.

References:

Baidu encyclopedia-mobile phone charger