A, the working principle of the protection circuit rjzservice manual download site
 rjzservice manual download site
 rjzservice manual download site
Panasonic TC - 29 gf35g protection circuit is shown in figure 1, is mainly composed of two parts; Figure 1. The upper part is from the special microprocessor protection (6 feet of peripheral discrete component protection circuit, figure 1 half part is composed of the bus system protection circuit. rjzservice manual download site
 rjzservice manual download site
1, the microprocessor 6 foot protection circuit rjzservice manual download site
 rjzservice manual download site
Microprocessor IC1213 (MN1874033T4X) of 6 feet is to protect the separate test pins, external protection of all stripes detection circuit, to test the power supply and line field scanning circuit. During normal work of the television, 6 feet for low level; Tested circuit failure occurs, to 6 feet high input level, the microprocessor based on judging the malfunction of the tested circuit from the output end of 33 standby control switch machine control voltage, the implementation of standby protection, at the same time control indicator light display fault information from 32 feet. rjzservice manual download site
 rjzservice manual download site
The normal boot, the microprocessor IC1213 33 feet for high level 5 v, through R857, R856, R854 Q852 switch machine control tube conduction, relay RL801 electric off, power on the main switch; The standby or protection, the microprocessor of 33 feet into a low level 0 v, Q852 cut-off, RL801 electrical disconnect, main power shut down. rjzservice manual download site
 rjzservice manual download site
A + B microprocessor 6 foot external overvoltage detection, line over-current detection, a fault detection, overvoltage detection, power rectifier circuit overvoltage detection of multiple fault detection circuit. rjzservice manual download site
 rjzservice manual download site
(1) + B overvoltage by it, R831 bleeder circuit and detection circuit regulator tube D832 composition. + B, when the voltage is normal, it with R831 partial pressure of anode voltage D832 acuities were 10 v, lower than the voltage value of the voltage regulator tube D832 10. 4 v, D832 cut-off, affect to protect circuit; When a + B voltage is too high, more than set value 10 D832 negative voltage. 4 v, D832 conduction, after conducting voltage to protect triode Q856 base, make Q856 conduction will switch machine control tube Q852 base between low, causing Q852 cut-off, relay RL801 disconnect, go to the main power grid is cut off, TV to enter standby mode.

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