Panasonic CT 30WX52, Руководство по обслуживанию

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1.4. X-Radiation
Warning:
1. The potential sources of X-Radiation in the monitor set are the high
voltage section and picture tube.
2. When using a picture tube test jig for service, make sure that jig is
capable of handling 37.2kV without causing X-Radiation.
3. For continued X-radiation protection, in case that at least one of the
components listed below is replaced, follow the adjustment
procedure of the high voltage circuit. Precise adjustment is
necessary for Serviceman Mode to protect X-Radiation. Refer to
"High Voltage and X-Radiation Protective Circuit Adjustment
section".
T551, IC1501, IC4002, D512, D1503, R520, R521, R522, R809, R810,
R1506, R4081, R4084, R1505, R1515 C481, C528, C1506, C1507,
RL801
1.5. Hold Down or Safety Circuit Information
To monitor the high voltage, the positive DC voltage from the cathode D512 is applied through
R1507 and other resistors to pin 3 of IC1501, which is the input terminal of the X-ray Protection
Circuit. The voltage at pin 2 of IC1501 is 5.90 ± 0.03voltage. Under normal conditions this voltage is
insufficient to activate the X-ray Protection Circuit.
If the voltage at pin 3 of IC1501 increases over the voltage at pin 2 of IC1501 increases and causes
the X-ray Protection to activate. Then it causes the shut down works.
In the process described above, the voltage at pin 3 of IC1501 is compared with the voltage at pin
2 of IC1501.if excessive beam current is drawn, the voltage at oin 3 of IC1501 increases. When the
voltage at pin 3 of IC1501 over the voltage atpin 2 of IC1501, the voltage at pin 1 of IC1501
becomes "high" and feeds into pin 45 of micro-controller IC4002 through R4084.The micro-
controller then turns off Q802, causes the AC power relay RL801 to unlatch and turns off the
receiver.
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