Nowadays, wireless charging technology makes mobile phones, Bluetooth headsets and other terminal equipment and wireless chargers get rid of the limitation of lines, and realizes the complete separation of equipment and charging power supply. Today, with the rapid development of science and technology, wireless charging technology has begun to be used in The application in various fields shows broad development prospects. Today, let's understand the standard of wireless charging coil charging.
For a fixed operating frequency, the quality factor Q mainly depends on the shape and size of the wireless charging coil and the materials used. Standard wireless charging coil technology generally specifies the value of the quality factor. For wireless charging coils with the same volume and shape but different winding arrangements, The ratio of inductance L to resistance R remains unchanged. In order to distinguish different wireless charging coil structures, it makes sense to define this ratio as the quality factor q.
The voltage induced by the same current in the inductor varies with frequency f and the apparent power of the device. The general definition of the figure of merit is based on the ratio of the apparent power of the device to the power loss. From this definition, the figure of merit for a wireless charging coil can be derived:
Q=ωL\/R
where ω=2πf:
The quality factor Q can take values from 0 to infinity, although wireless charging coils are difficult to obtain values much greater than 1000. For mass production, expect a quality factor of about 100. A quality factor below 10 is not very useful. These values Must be considered in typical order of magnitude.
The charging standard of the wireless charging coil is a wireless charging standard proposed by Qi's Wireless Power Consortium (WPC). The wireless charging coil adopts electromagnetic induction technology, and has a transmitter coil and a receiver coil on the wireless charging base and the mobile phone respectively. The transmitter The coil generates a periodically changing magnetic field, and the receiver coil senses the change in the magnetic field to generate current. Therefore, the wireless charging coil is mainly point-to-point charging, that is, one transmitting coil corresponds to one receiving coil. This wireless charging method also has high requirements on the location of the coil. It can't be charged without a standard.
At present, there are more than 200 companies such as Apple, Sony, 3 Star, LG, Nokia, Philips, TI, etc. This makes the wireless charging coil more famous. 3 Star already has many devices that support wireless charging coil charging.