Stable and Secure Contactless Connectivity of Power and Data in Rotational Applications

A contactless connectivity solution is introduced to provide stable and secure transmission of power and data with high-data rate to a rotational security camera to replace the conventional slip ring, which is normally expensive and introduces reliability issues. The power transmission up to 15W is realized using ring coils with induction coupling for stable and constant power level during rotation. The Wi-Fi chipset is adopted to transmit the video stream in H.264 format with data rate of 54Mbps. To ensure the consistence and security of the RF signal during the rotation, the near-field ring antenna is developed. Furthermore, the contactless power coils are specifically designed to reduce the eddy current induced on the antenna and the metal shaft to improve the efficiency of the contactless power. Therefore, we could achieve 78% efficiency of power transmission and -25dB signal receiving power normalized to the transmission with less than -2dB variation during the continuous rotation in 360 degrees.