With the iPhone 8 released, the discussion of wireless charging technology is more and more rampant.

Usually, we think electric and magnetic are related, so most of the questions about the principle of wireless charging are based on the electromagnetic introduction phenomenon or derived from it.

There are 4 methods to achieve mainly wireless power transmission. We talk to the first one today.

Magnetic induction

Give the primary coil of a certain frequency of alternating current, the electromagnetic induction in the secondary coil will produce a certain amount of current, thereby transferring energy from the transmitter to the receiver.

This principle is similar to the commonly used transformer principle in power system. When the primary side (primary coil) of the transformer is energized with alternating current, the secondary side (secondary coil) induces electromotive force due to the principle of electromagnetic induction. If the secondary circuit is connected, that is, Induction current can occur, so that you can achieve the power from the transmitter coil to the receiver coil wireless transmission.

At present, the way of transferring electric energy by using this method has been widely applied in the market of low-power and short-distance wireless charging, such as electric toothbrushes, mobile phones and cameras, etc. small portable electronic devices,  which are generally charged by a charging base. The power transmitting coil is installed in the charging base, and the receiving coil is installed in the electronic device.