A prosthetic foot gasket for sealing between a foot shell covering a foot portion of an endoskeletal prosthetic leg and a leg portion thereof comprises a peripheral body having an upper surface and further defining a central opening therethrough. The buck switching regulator includes an on-time control circuit for generating a first signal for turning off the high-side switch at the expiration of a first on-time duration or at the expiration of a maximum on-time. Accordingly, without increasing the volume of the portable wireless terminal, an antenna space can be ensured and radiation performance can be improved. A speed difference integral calculator calculates an integral component of the speed difference based on the speed difference and an integral gain.