松下mx-4大屏幕彩电x射线保护原理与检修（X ray protection principle and maintenance of Panasonic mx-4 large screen color TV）.doc

松下mx-4大屏幕彩电x射线保护原理与检修（X ray protection principle and maintenance of Panasonic mx-4 large screen color TV） X ray protection principle and maintenance of Panasonic MX-4 large screen color TV Panasonic MX-4 large screen color TV core will be the companys latest ultra large scale integrated circuit AN5193K as a video signal processing center. At present, there are many multi-functional and high quality digital color TV sets assembled by MX-4 movement, such as female TC-2502GS, TC-2555R / RS, TC-2900G / GS, TC-2902G / GS, TC-2998, TC-2998R / RS, etc.. (1 Pages altogether) Key words: large screen color TV, Panasonic movement, VLSI, video signal processing, maintenance, digital color TV, MX, TC assembly Article snapshot: TC one, 2502GS, TC, 2555R / RS, TC, 2900G / GS, TC, 2902G / GS, TC, 2998, TC, 2998R / RS, etc.. .X radiation protection principle of AN5193K circuit (IC601) is the 43 foot X ray protection signal input normal working voltage is 0V, X ray protection up to about 1V, off line scanning system through the internal logic circuit, play a protective role. The X - ray protection circuit, as shown in the drawings, is equipped with the following 3 protection functions. The 1. line output overvoltage protection line, the 5 pin of the output transformer T501 provides the picture tube filament voltage, which is directly proportional to the high voltage of the picture tube. When the output overvoltage, by D508, C510 by R5l1, rectifier filter, R512 pressure sampling, the voltage on the R512 is higher than the breakdown voltage regulator tube D509, D509 conduction, IC601 43 feet into high level, forcing the line scan circuit to stop working. When the output stage is working properly, the R512 share of the low voltage breakdown voltage, D509 D509 as IC601 school in 2004 twelfth with responsibility placed X ray protection circuit of 43 feet for the 0V, does not affect the normal work of the line scanning circuit. 2. picture tube electron beam current over-current protection