Abstract: A cavity-type seed-metering device with a magnetic seed protection assembly is provided, which includes a seed-metering device shell, a seeding plate and a seeding shaft. The seeding plate rotatably mounted in the seed-metering device shell through the seeding shaft. A seeding channel is formed in the seed-metering device shell. Multiple cavities are formed in the seeding plate. Seed filling orifices connected with the cavities are formed in one side of the seeding plate. Seeding outlets connected with the cavities are formed in a circumferential surface of the seeding plate. A magnetic hinge is rotatably connected with the seeding outlet. A notched magnetic ring is fixed in the seed-metering device shell. The magnetic hinge can close the seeding outlet under a magnetic force of the notched magnetic ring. A magnetic block that can attract the magnetic hinge for opening the seeding outlets is arranged in the seeding channel.

Abstract: A power supply includes an input power supply, a multiphase interleaved parallel converter, and a current sampling apparatus. The input power supply is configured to supply power to an input end of the multiphase interleaved parallel converter. The multiphase interleaved parallel converter includes at least two phases of converters that are connected in parallel. The current sampling apparatus is connected to a switching transistor in each phase of converter in the at least two phases of converters that are connected in parallel. The current sampling apparatus includes a first sampling resistor. The first sampling resistor is connected to the input end or an output end of the multiphase interleaved parallel converter. The current sampling apparatus is configured to determine an inductor current of a first phase of converter based on a first current that is of the first sampling resistor and that is collected at a first moment.