Abstract: The present invention discloses a high step-down modular DC power supply, belonging to the field of power electronics technology, and the high step-down modular DC power supply includes an upper modular cascade circuit string, a lower modular cascade circuit string, a load, and an input source, where the upper modular cascade circuit string includes i upper sub-module circuits, and the lower modular cascade circuit string includes j lower sub-module circuits. A combination manner of module circuits includes: upper module string cascading, lower module string cascading, and hybrid cascading of the upper module string and the lower module string. The power supply is formed to be a high voltage step-down ratio power supply with high voltage direct current input and low voltage direct current output through modular cascading.

Abstract: The invention provides a device for full-automatic, ultra-low pressure, fractionation-free and non-destructive extraction of water, including a control box, an extraction part, an ultra-low temperature cold trap and a transmission device, wherein the control box and the extraction part are located at the top of a cabinet, the ultra-low temperature cold trap is located inside the cabinet, a touch screen is arranged on the control box, a temperature control meter is arranged on a side face of the control box, the extraction part includes an upper layer plate, a middle layer plate, a bottom plate and a test tube, the bottom plate is fixedly installed on the cabinet, the test tube is accommodated in the ultra-low temperature cold trap, and the transmission device is fixedly installed on the bottom plate.

Abstract: The invention provides a device for full-automatic, ultra-low pressure, fractionation-free and non-destructive extraction of water, including a control box, an extraction part, an ultra-low temperature cold trap and a transmission device, wherein the control box and the extraction part are located at the top of a cabinet, the ultra-low temperature cold trap is located inside the cabinet, a touch screen is arranged on the control box, a temperature control meter is arranged on a side face of the control box, the extraction part includes an upper layer plate, a middle layer plate, a bottom plate and a test tube, the bottom plate is fixedly installed on the cabinet, the test tube is accommodated in the ultra-low temperature cold trap, and the transmission device is fixedly installed on the bottom plate.