Wireless power supply is a general term for technologies that transmit power in a non-contact manner without using cables. Is it easy to imagine the iPhone’s stationary charger (Qi project)? However, there are many people who think only about the Qi standard when it comes to wireless power supply due to a common misconception. Wireless power supply can be roughly divided into 6 types of transmission methods, including the Qi standard magnetic field coupling method, and each method has its advantages and disadvantages. In other words, it is necessary to select an appropriate method for each application instead of using wireless power supply all at once. * What is the Qi standard? An international standard for wireless power supply established by the Wireless Power Consortium.