Provided is a battery-less sensor circuit including a power generation element, a first switching element, a voltage control circuit, a first storage capacitor, a sensor circuit, and a load. The power generation element is connected to the first storage capacitor via the first switching element. A power supply terminal of the sensor circuit is connected to an input terminal of the first switching element. The voltage control circuit is configured to control a current passing through the first switching element through reception of a voltage of the input terminal of the first switching element. The load is connected to the first storage capacitor and the sensor circuit.