Abstract: A Z-axis that is integrated with storage, commixture and extrusion of materials, including a vertically-moving bucket, and a vertically-moving unit connected to the vertically-moving bucket. The vertically-moving unit can drive the vertically-moving bucket to move vertically. The vertically-moving bucket is used to store printing materials. A printing nozzle connected to the vertically-moving bucket is provided at the bottom of the vertically-moving bucket, which is connected with the printing nozzle through a stirring unit. The vertically-moving bucket replaces the existing vertically-moving axis, so that the printing nozzle can directly communicate with the vertically-moving bucket without pipelines to connect the printing nozzle to the vertically-moving bucket. Also, a 3D building printer that does not need to erect a relaying bucket in the sky, which solves the problem of pipeline blockage and cleaning.

Abstract: A method and apparatus for determining the entry and exit from a pulse skipping mode in a power supply is provided. The power supply may incorporate a buck regulator. The method begins when current is sensed at an inductor of a power supply. This sensed current is then compared with a predetermined threshold current value. If the comparison reveals that the current is below the predetermined threshold current value, a pulse skipping mode is entered. If the current is found to be above the predetermined threshold the pulse skipping mode is not entered and normal operation continues. The apparatus includes a transconductance amplifier, an offset voltage source, a reference power supply reference voltage source, first and second voltage comparators, and a processor.