tailieunhanh - CHAPTER 3 - ELECTRICAL SAFETY

Tầm quan trọng của an toàn điện Với bài học này, tôi hy vọng để tránh một sai lầm phổ biến được tìm thấy trong sách giáo khoa điện tử của một trong hai bỏ qua hoặc không bao gồm chi tiết đầy đủ các chủ đề về an toàn điện. Tôi giả sử rằng bất cứ ai đọc cuốn sách này có ít nhất một sự quan tâm qua thực sự làm việc với điện, và là chủ đề an toàn là hết sức quan trọng. Những tác giả, biên tập viên, và nhà xuất bản không để kết hợp. | For the morbidly curious, Charles Dalziel's experimentation conducted at the University of California (Berkeley) began with a state grant to investigate the bodily effects of sub-lethal electric current. His testing method was as follows: healthy male and female volunteer subjects were asked to hold a copper wire in one hand and place their other hand on a round, brass plate. A voltage was then applied between the wire and the plate, causing electrons to flow through the subject's arms and chest. The current was stopped, then resumed at a higher level. The goal here was to see how much current the subject could tolerate and still keep their hand pressed against the brass plate. When this threshold was reached, laboratory assistants forcefully held the subject's hand in contact with the plate and the current was again increased. The subject was asked to release the wire they were holding, to see at what current level involuntary muscle contraction (tetanus) prevented them from doing so. For each subject the experiment was conducted using DC and also AC at various frequencies. Over two dozen human volunteers were tested, and later studies on heart fibrillation were conducted using animal subjects.