External Source Control Logic - Daewoo DTF-2950-100D Service Manual

5.5.7 EXTERNAL SOURCE CONTROL LOGIC

The following schematic, illustrates the logic of control for the two SCART connectors.
The terms used in the schematic are described below;
1. AUTO represents a situation where the television has self-selected its picture source. This
could be when the SCART SLOW SWITCHING pin has gone to a high state, and the AV 1
input is selected without the intervention of the user.
2. FORCED represents the change of source which has been commanded by the user (using
the EXTERNAL button). The user always has priority, and can override the AUTO change of
source by the television.
3. AV KEY represents the EXTERNAL button of the remote control, or on the television.
4. S/SW 1, or S/SW 2 represent the SLOW SWITCHING inputs of the first SCART (AV 1) or
second SCART (AV 2), these each being pin number 8.
5. F/SW 1 represents the FAST SWITCHING input of the first SCART (AV 1), on pin number 16.
The second SCART, AV 2, input does not possess a FAST SWITCHING input.
The HIGH state of a slow switching input represents the request from the external source to be
selected by the television. Whether this is accepted or not depends on the position in the logic
diagram. The general rule is that the user always has priority, so the use of the AV KEY will
always result in a defined logic path being followed.
Under certain circumstances, defined in the diagram, the change of state of a slow switching
input will result in the automatic change of source by the television. This change, such as the
change from RF broadcast to the AV 1 input, can always be overridden by the user after the
event.
Each line on the diagram, with its associated text, represents the exact conditions under which
the change of state will occur. Sometimes this will be accompanied by another action which will
be automatically performed by the television, being to either ENABLE or DISABLE F/SW 1.
Europe R&D
Downloaded From TV-Manual.com Manuals
CP-850FX Service Manual
59