POWER TRANSMISSION SYSTEM

Provided is a power receiver and a power transmitting system that can improve a supply balance of electric power. A power receiver includes a first secondary-side resonant coil, including a first terminal and a second terminal, that receives electric power from a primary-side resonant coil through magnetic field resonance generated between the primary-side resonant coil and the first secondary-side resonant coil; a rectifier circuit, coupled to the first terminal and the second terminal, that rectifies alternating-current power input from the first secondary-side resonant coil; a smoothing circuit coupled to an output side of the rectifier circuit; a pair of output terminals coupled to an output side of the smoothing circuit; a switch, inserted in series on a line between the rectifier circuit and the smoothing circuit, that switches a coupling state of the line, and a drive controller that drives the switch through a first PWM drive pattern determined by a first duty cycle and by a first frequency that is less than or equal to a frequency of the magnetic field resonance. The first duty cycle is set based on a first efficiency of electric power reception of the first secondary-side resonant coil, a first rated output of a first load coupled to the pair of output terminals, a second efficiency of electric power reception of a second secondary-side resonant coil of another power receiver that receives electric power from the primary-side resonant coil through magnetic field resonance generated between the primary-side resonant coil and the second secondary-side resonant coil, and a second rated output of a second load to which electric power is supplied from the other power receiver.