Technology of Q 2500 colour TV set

Technology of Q 2500 colour TV setIf the SDA 6000 is waiting for data from a peripheraldevice, then the 22 kHz must beswitched at L level on pin 90. The device addresseddampens the 22 kHz signal for therequired period by changing the input impedance,so that the data can be transferred tothe SAT unit of the TV set. The SAT unitchanges this signal into L and H pulses of thesame duration, which are applied to connectorW 1211, pin 7 on the signal board. The signalis inverted in transistor Q 2831. The DiSEqCinformation is then made available to the SDA6000 on pin 7.4.2 Bus systems in Q 2500 chassisSeveral bus systems are used in order to implementthe large number of switching andcontrol functions of the Q 2500 chassis in areasonable time, and for error-free addressingof the ICs.For this the SDA 6000 generates three I²Cbussystems with which the memory IC, thecontrol ICs for the HF/IF component, the ICson the SAT unit, the converter for video andaudio, the building levels in the video section,for PIP and multi-sound processor are controlledThe I²C bus systems 1 and 2 on the otherhand operate with a common clock line andseparate data lines. The I²C bus system 0operates as usual with separate data andclock lines.In all I²C bus systems there is constant datatraffic. If the Bus Stop command is issued orthe device is started with the Power On command,the bus lines are then set to 5 V d.c.Document Q 2500 72 © Loewe ProCollege