This Small Business Innovation Research (SBIR) Phase I project is intended to develop a differential drive system capable of powering a mid- to long-range wireless power delivery system. Conventional drive circuits create significant quantities of noise and interference that prohibits the proper operation of wireless delivery systems. Due to the transmitting function of a wireless power system, the implications of this noise and interference are significant and limit the usability of most wireless power systems. A differential drive circuit used to power the wireless power transmitter greatly reduces noise by relying on an oscillating signal to transmit power between transmitters and receivers. This oscillation reduces the magnitude of noise of each oscillation, but more significantly pairs and therefore cancels noise generated system as a whole. With careful tuning and alignment, these oscillations are correlated, canceling the noise and reducing the noise generated. Designing a differential drive to power the circuit allows a variety of wireless power systems to meet all regulatory requirements and transmit power to handsets and other electronic systems without excessive interference.
The broader impact/commercial potential of this project is to allow for widespread adoption and integration of wireless power delivery systems. Prior limitations on commercial exploitation of wireless power have been limited by regulatory limitations and the excessive noise created by these systems. Using a differential drive, permits a variety of transmitters and applications to be developed, as well as increase the potential range of wireless power. In addition to passing regulatory requirements, the differential drive system permits wireless power receivers to be integrated into a variety of electronic hand-sets that were previously impossible. The differential drive will reduce interference, such that prior applications such as mobile phones, laptops, and other handhelds can now be powered wirelessly. The implications of this project?s goals are significant in expanding the range and usability of wireless power. Reductions in noise and interference will improve usability of wireless power systems, and increase adoption in both the consumer and military electronics fields.
Contemporary portable electronic devices incorporate features such as large screens, fast network connections, and powerful processors. These features enable users to access an ever expanding library of rich internet content, but they have the negative consequence of significantly reducing battery life. Wireless charging technology can mitigate the problems associated with short battery life by providing users with more convenient access to power. WiPower participated in the National Science Foundation Small Business Innovative Research (SBIR) program to develop extended range, flexibly coupled, wireless power systems. The technology allows users to charge properly equipped electronic devices by placing them in a designated charging area. The charging area can be a table-top tray, or it can be embedded in surfaces such as desktops and automobile consoles. The technology is distinct from today’s commercially available wireless charging systems because it insensitive to the alignment of a device relative to a charging area. It is also uniquely capable of powering devices through relatively thick surfaces, which allows the charging system to be seamlessly integrated with most environments. Once commercialized, the technology offers a number of potential benefits: Seamlessness: Any surface can become a charging area. Convenience: Charging is as simple as dropping a device in a charging area. Accessibility: The technology is designed to support a wide variety of devices. Universal wireless charging hubs can deployed in coffee shops, airports, and other common gathering places. A wireless power system is comprised of a transmitter and a receiver subsystem. The transmitter is responsible for converting electrical current into a magnetic field. Unlike electrical current, magnetic fields can traverse non-conductive surfaces, such as table tops. When a reciever is placed in a transmitter’s magnetic field, it produces electrical current that is usable by a portable electronic device. One of the key challenges associated with the commercialization of flexibly coupled wireless power technology, was the requirement to create a system that would not interfere with other products. WiPower developed a several new technologies, such as a low noise amplifier, that greatly reduced or eliminated most of the interference problems. Thanks, in part, to the funding of the National Science Foundation, extended range, flexibility coupled wireless power systems may become commercially viable.
