Power strips; Pulse generators for testing electric current; Pulse generators in the nature of electronic circuits; Electrical power connectors; Renewable battery system to provide backup power; Electrical power distribution units; Power-line transmission machines and apparatus; Carrying cases, holders, protective cases and stands featuring power supply connectors, adaptors, speakers and battery charging devices, specially adapted for use with handheld digital electronic devices, namely, cell phones; Semiconductor power elements; Power amplifiers; Power adapters for use with recreational vehicles