This standard specifies the product classification, requirements, test methods, inspection rules, marking, packaging, transportation, and storage of power equipment (hereinafter referred to as equipment) in cable distribution systems for 5MHz to 1750MHz television and sound signals. This standard applies to power equipment in cable distribution systems for 5MHz to 1750MHz television and sound signals. 2. The provisions contained in the following standards constitute the provisions of this standard by reference in this standard. At the time of publication of this standard, all versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T 11318.1-1996 Equipment and components for cable distribution systems for television and sound signals - Part 1: General specifications - Definitions. The following definitions are used in this standard, and other definitions shall comply with the relevant provisions of GB/T 11318.1. 3.1 Line power unit is a device in the cable distribution system that converts 220 V, 50 Hz AC mains power into low voltage AC power to supply power to distant amplifiers. 3.2 Power feed injector is a device in the cable distribution system that injects low-voltage AC power from the power supply into the coaxial cable used for signal transmission, without affecting signal transmission. 3.3 Change rate of output voltage The change rate of output voltage refers to the relative change in the output voltage of a power supply device with the specified input voltage and load current. 3.4 Short circuit current The output current value of the line power supply after a short circuit occurs at the output end of the line power supply under rated power frequency and rated input voltage conditions. 3.5 Transient recovery time When the input voltage suddenly changes from 80% of the rated value to 115%, or the load current suddenly changes from the rated value to zero, the time interval between the output voltage of the power supply unit leaving the regulated value for the first time and finally entering the regulated zone
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