According to one embodiment, a power control circuit includes a converter, a signal generating circuit, an estimation unit, and a controller. The converter includes a switching circuit and is configured to transform an output voltage from a power generator. The signal generating circuit is configured to transmit a signal to the switching circuit. The estimation unit is configured to determine a switching operation condition based on vibration information indicative of a vibration applied to the power generator. The controller is configured to control an operation of the switching circuit based on the determined switching operation condition.