Wireless power is transferred from transmitter to receiver coil using inductive coupling principle. For wireless power transfer to work efficiently, frequency of the transmitter and the receiver must be tuned to the same frequency. LC tank of transmitter side produces an oscillating magnetic field of the tuned frequency. LC tank of receiver side is same as the frequency of transmitter side, thus achieving high efficiency. Let us construct a wireless LED.
This wireless-powered LED can be used in mobile phone battery chargers, electric tooth brushes and low-powered loads such as LEDs, SMPSes, rotors and so on. The author’s prototype is shown in Fig. 1.