Abstract: Provide are a power reception device, a wearable device, and a non-contact power feeding system that can improve the transmission efficiency while suppressing upsizing of the circuit thereof. A power reception device (3) includes a variable capacitance circuit (100) and a power reception coil (41) constituting a resonance circuit together with the variable capacitance circuit (100), in which the variable capacitance circuit (100) includes a first capacitor (C1) and a second capacitor (C2) connected in parallel to each other, a first switch (Tr1) connected in series to one end side of the first capacitor (C1), and a switch control circuit (110) that controls turning on and off of the first switch (Tr1) and includes a first comparator (OP1) that supplies a first control voltage to the first switch (Tr1) according to a comparison result between a reference voltage and an AC voltage applied to the second capacitor (C2).

Abstract: Provide are a power reception device, a wearable device, and a non-contact power feeding system that can improve the transmission efficiency while suppressing upsizing of the circuit thereof. A power reception device (3) includes a variable capacitance circuit (100) and a power reception coil (41) constituting a resonance circuit together with the variable capacitance circuit (100), in which the variable capacitance circuit (100) includes a first capacitor (C1) and a second capacitor (C2) connected in parallel to each other, a first switch (Tr1) connected in series to one end side of the first capacitor (C1), and a switch control circuit (110) that controls turning on and off of the first switch (Tr1) and includes a first comparator (OP1) that supplies a first control voltage to the first switch (Tr1) according to a comparison result between a reference voltage and an AC voltage applied to the second capacitor (C2).