BLOCK DIAGRAM OF MONOCHROME TV RECEIVER.pptx

the block diagram of monochrome and color television receiver

1. BLOCK DIAGRAM OF MONOCHROME TV RECEIVER

2. THE DIAGRAM SHOWING INPUT AND OUTPUTS

3. BLOCK DIAGRAM OF MONOCHROME TV RECEIVER

4. FUNCTION OF EACH BLOCK SECTION

5. CONTINUATION………

6. CONTINUATION………

7. NOTE AGC section : so an A utomatic G ain Control (AGC) circuit is used to automatically control the gain of the amplifiers. separation of sync pulses becomes easy. controls sound signal level . Sync separator section: this section consists of a sync separator integrator and differentiator so the output of sync separator contains both the horizontal and vertical sync pulses. the differentiated horizontal sync pulses of line frequency are used to trigger the horizontal oscillator.

8. CONTINUATION……… Horizontal and vertical oscillator section ; vertical section consists of vertical oscillator output amplifier and vertical deflection coil. similarly the horizontal is synchronized by the trigger pulses from the differentiator. Antenna section : to receive the tv signals, antenna is mounted at the top of a building. converts the received electromagnetic waves into electrical signals. a half wave length antenna is mostly used for uhf band channels. normally yagi antenna is used in tv receiver.

9. COLOR TELEVISION RECEIVER T he color tv receiver is similar to the monochrome system expect that here we have a color demodulator section.

10. COLOR TELEVISION RECEIVER……… The color tv receiver consist of five section namely Radio Frequency(RF) Video Section Pal decoder/Color Processing section Synch Section Sound Section RF TUNER I t consists of VHF(very high frequency) and UHF(ultra high frequency). it selects the desired t.v channel. Video section I t consist of video detector which provides composite color signal(CCVS). this CCVS consist of pure video, synch pulses, color signal, color bus, AGC bias is also obtained from this section.

11. COLOR TELEVISION RECEIVER……… PAL Decoder/Color Processing section I t consist of color demodulation which provides demodulated u and v signal. pal decoder provides R.G.B signal Where, R-Red G-Green B-Blue which applied to picture tube and pal decoder also consist of acc (automatic color control)

12. SOUND SECTION T he output of FM (frequency modulator) detector is processed and the audio signal is reproduced by the speaker.

13. Different stages of television receiver A television receiver includes; A tuner stage, A selective filter stage connected to the tuner stage, and A intermediate-frequency stage connected to the selective filter stage. A field-strength-detection stage is also provided, which generates a field strength signal proportional to the field strength of the received signal. the selective filter stage includes a transfer function that is modifiable by a control signal derived from the field strength signal.

14. Different stages of television receiver

15. TUNER stage: RF tuner selects the desired channel frequency band from the receiving antenna. COMMON IF AMPLIFIER: there are 2 or 3 stages of if amplifiers. VIDEO DETECTOR : used to detect video signals coming from last stage of if amplifiers. VIDEO AMPLIFIER: it amplifies the detected video signal to the level required. scanning and synchronizing circuits: scanning is the process where picture elements are converted into corresponding varying electrical signals.

16. SOUND IF AMPLIFIER : detected audio signal is separated and selected for its if range and amplified. FM SOUND DEMODULATOR : fm sound signal is demodulated in this stage. AUDIO AMPLIFIER: fm demodulated audio signal is amplified to the required level to feed into the loud speaker. LOUD SPEAKER : loud speaker converts fm demodulated amplifier signal associated with picture being televised into proportionate sound signal

17. PICTURE TUBE: in picture tube the amplified video signal is converted back into picture elements. scanning: Scanning is the process used to convert the optical into electrical signal. fastest movement of electron beam on the image is called scanning.