Application of wireless power supply
For wireless power supply or charging devices, the primary and secondary coils are divided into two independent parts, so the coupling between the coils is relatively loose. The system is equivalent to an independent loosely coupled transformer, and ferrite cores are selected to improve its coupling efficiency and reduce magnetic leakage.
Plastic film, a professor at the University of Tokyo in Japan, has designed an innovative and versatile power supply. For example, it could be placed on a floor or table, or embedded in a wall, to power a light-emitting diode and decorative lights on a Christmas tree, or a light bulb or small motor in a fish tank or water tank. The thin film power supply consists of four layers of plastic film. The bottom layer is a conductivity-controlled organic transistor, topped by a copper coil that senses the proximity of compatible electronic devices, and topped by a mems switch that switches power supplies, above it is a copper coil for transmitting electricity. Production process using screen printing and similar ink-jet printing of the new process. It works like this: When an object is within 2.5 cm of the film, the nearest mems switch is connected to the power supply, and the induction coil powers the device using induction. The technology is said to be very efficient, with a power transfer efficiency of 81.4 percent. The target price is $100 per square meter.