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5.4.5
OVER CURRENT PROTECTION
In case of overload, the SMPS secondary voltages will drop. The voltage on pin 18 of microcontroller drops below a
reference voltage (x.xxV). The controlling software which continuously monitors this voltage will switch the set to stand
by mode. To power on the set again the user must switch it off using the main power switch. Appropriate hysteresis
guaranty a reliable operation.
5.5 TELETEXT DISPLAY
National character option bits C12, C13, C14 are transmitted in the page header of a given teletext page. The national
option bits are intended to change (or exchange) 13 characters within the G0 character set, according to the needs of
each national language.
These codes represent, for a given broadcaster, the intended language that the teletext page should be displayed in. As
there are only 3 bits, there are only 8 codes available to cover all the possible language combinations. This means that
for a received code there are several possibilities meanings, according to the local code of practice.
This is not as bad as it first seems, as we use the user-selected OSD language to identify the intention of the
broadcaster. For example, a user wishing to see Russian teletext should select
Russian OSD language, otherwise he would not have correct teletext display on the TV.
The table below allows the reader to understand the relationship between selected OSD language (which is under user
control), the teletext language display (selected by national option bits in transmission page header) and the Packet 26
language selection (selected within packet 26 of the transmission page).
An example: For Greek teletext display, (if national option code 1 1 1 is received from the broadcaster), the user should
select the Greek OSD language. Even if English, French, German, Italian, Spanish, Dutch, Danish, Finnish, Norwegian
CP-850/F Service Manual
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Summary of Contents for DTK-28 Series
Page 7: ...CP 850 F Service Manual 6 1 2 CHANNEL FREQUENCY TABLE 1 2 1 CHANNEL FREQUENCY TABLE...
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Page 46: ...CP 850 F Service Manual 45 5 CP 850 F CHASSIS DESCRIPTION 5 1 BLOCK DIAGRAM...
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