Design of a practical human-powered contactless charger for cellphone

Based on the electromagnetic induction effect, a practical human-powered contactless charger for cellphone (HCCC) with discrete magnet elements is developed. This system entirely powered by human could supply strong enough electricity for real need, which guarantees its pervasively important value. The performance of the system is demonstrated by successfully charging a cellphone. According to the experimental measurements, the maximum open-circuit voltage for the receiver could reach more than 16V, when the human power harvester (HPH) is driven by hand at a rotation speed of 150r/min and the gap between the receiver and transmitter is 3mm. When a resistance with 100ω is connected to the receiver, a maximum output voltage of 12V can be obtained at the same working condition. Through a converter, the output alternating voltage of the receiver can be tuned into a stable direct voltage of 6V which would be favorable for driving a cellphone or more other mobile electronic devices. With multiple advantages over existing battery approaches such as contactless energy supply, pervasive chargeability by human power, the HCCC is expected to offer an easily available wireless green energy source which would be highly useful for different mobile consumer electronics1.