Technology of Q 2500 colour TV set
Technology of Q 2500 colour TV set
Technology of Q 2500 colour TV set
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
<strong>Technology</strong> <strong>of</strong> Q <strong>2500</strong> <strong>colour</strong> <strong>TV</strong> <strong>set</strong>2.11 NF output stagesThe two amplitude controlled VF signals areoutput from pins 56 and 57 <strong>of</strong> MSP 3411 onthe signal board. The signals are applied tothe base <strong>of</strong> transistors Q2081/2083. The transistorsare switched as impedance convertersto prevent, as far as possible, the coupling <strong>of</strong>interference pulses on the VF wires betweenMSP and the output ICs.The VF signals reach the two output stagesvia the coupling capacitors C 2082/476. Inbetween are the two mute transistorsQ 1586/88. (See signal board).U+NFC466U+NFR466Q<strong>2500</strong> Stereo sound output stageC468R468LS-RLS-L12RSIGUMUTE345W61013pol13polW211123Mute456U-NFU-NF9 pin Cubeconnector123456789123456789W470C467B210B214U12B222R46721W47121W481R478L479C478L489C488C473C471U+NF13 27 10R4796 414 I474TDA7296 1R47598 3C477 15C475U-NFU+NFR488R489C481U+NF14C485R485C483U+NF13 27 106 4I484TDA7296 198 315C487U-NFR473 C472C474C489C484D474R474R476R483 C482C476R484C486R472R477R471C079R482UMUTEC492R492Q469R469D491The output stages are implemented easily asall control processors (volume, tone, balance)as well as base width switching are processedin the MSP.Compared to previous models the Q <strong>2500</strong> hasnew output stages. TDA 7296 is equippedwith an internal mute function that removesany residual on and <strong>of</strong>f switching interferencethat is not fully suppressed by the additionalmute switching.The internal mute switching is controlled onpins 9/10. If the voltage on the pins is
Change language