2 ª± sprite tv / av / s terminals of the switch ( see Figure 2) ic8039, {16}, {17}, {20}, {32} consisting of the input switching circuit pin and the output pin by cpu7 switching signal control to select internal / external signal . When the input low to ic803 {32} feet, the control circuit turns pip sprite tv signal input pin {20 } ; When the input is high, switch to the { 16} feet to the signal , {17 } . The signal is divided into two cases: the first case, when placed s -Video input , cpu6 feet high output , control switching manifold ic3075 feet, connected to ic3073 foot s terminal luminance signal → ic3076 → cn3022 → cn8012 → c844 → ic803 {17} feet, chroma signal → cn3021 → cn8011 → c843 → ic801 {16}; second case , when placed in the other three-way main screen tv av signal or the signal input from the integrated video converter ic304 {14} block is coupled to pin pin ic3071 composite video signal at a low level control cpu6 pin switch output pin to ic3076 , {17 } from the input pin ic803. ic8039 foot control due cpu6 feet high , close color notch and bandpass filters , s -Video input luma / chroma signal to the {16 } {17 } feet, no longer through the y / c separation circuit directly go to the following demodulation circuit ; pin is low when cpu6 , ic803 open notch and the color ink ribbon pass filter, ic803 {17} pin input composite video signal ( pin 16} { vacant ) into y, c signal is re-entering the following circuit .

 

3 ª± sprite light / color processing and synchronization signal separation into ic803 separate ways after "Input select " switch on cvbs input ( composite video signal ) or y / c after switching signal detection to identify , in three columns output ( the next issue Excerpts Figure 3 ) . The first pass color luminance signal wave notch filter out after the chrominance signal sent to the internal integration of luminance delay line for { 49 } pin output by the delay processing . Another pass chrominance bandpass filter to filter the luminance signal , and supplied to the chroma decoder circuit, in p / n demodulating decoder (r-y) and (b-y) of two color difference signals , respectively, from { 51 } {50 } pin output . p / n decoder required color subcarrier , { 43 } in the external pin 4 ª± 43mhz (pal) { 45} and the foot 3 ª± 58mhz (ntsc) crystal with a p / n decoder phase locked pll loop VCO circuit (vco) provided . { 46 } feet rc network of external phase-locked loop color filter. The color subcarrier oscillator frequency is automatically selected by the p / n decoder according to the input chrominance signal.

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