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: Disclosed are an ignition powder, a preparation method therefor and a use thereof, and an airbag gas generator, which belong to the technical field of ignition powders. The raw materials of the ignition powder include the following components in percentages by mass: potassium perchlorate. 30%˜50%; basic copper nitrate: 5%˜20%; a fuel: 15%˜60%; a metal oxide: 1%˜25%; and a metal powder: 1%˜25%, wherein the metal powder is at least one of a titanium powder, a magnesium powder, a copper powder, an iron powder, a zirconium powder, a hafnium powder, a tungsten powder or a silicon powder.

Abstract: Provided are a gas generant composition, a preparation method, and a gas generator containing the composition. The gas generant composition includes components having the following contents, in percent by mass: 40% to 60% of guanidine nitrate, 25% to 50% of basic copper nitrate, 0% to 7% of ammonium perchlorate, 1% to 10% of a slag-forming agent, and 0.05% to 5% of a release agent/lubricant, the slag-forming agent is used as a form-retaining agent, so that the tablets can retain their form before combustion very well after combustion, thereby completely avoiding burning of an inflatable bag due to melting and splashing of the combusted tablets. Moreover, ammonium perchlorate is used as auxiliary oxidizers, thereby reducing the amount of basic cupric nitrate used and reducing molten copper residues. The gas generant composition is mainly used in a gas generator for vehicle airbag.