A Bernoulli Spiral Coil Transmitter for Charging Various Small Electronic Devices

Wireless charging technology is built into a variety of devices. However, each of these products use a dedicated wireless charger, so when it comes to making better organizational use of space, being able to charge various devices with one transmitter is desirable. In this letter, we propose a Bernoulli spiral coil transmitter that can efficiently charge smart devices of various sizes. Our analysis shows that the proposed transmitter can maintain a certain coupling coefficient even when the diameter of the receiver coil is small, compared with the conventional Archimedean spiral coil transmitter. In other words, even if the diameter is small, the output power and power transfer efficiency of the proposed transmitter are higher than those of the conventional transmitter.