the block diagram of monochrome and color television receiver

1. a) BLOCK DIAGRAM OF MONOCHROME TV
RECEIVER

2. THE DIAGRAM SHOWING INPUT AND OUTPUTS

3. BLOCK DIAGRAM OF MONOCHROME TV RECEIVER

5. FUNCTION OF EACH BLOCK SECTION

6. CONTINUATION………

7. CONTINUATION………

8. NOTE
• AGC SECTION:
i. so an Automatic Gain Control (AGC) circuit is used to automatically
control the gain of the amplifiers.
ii. separation of sync pulses becomes easy.
iii. controls sound signal level.
• SYNC SEPARATOR SECTION:
i. this section consists of a sync separator integrator and
differentiator
ii. so the output of sync separator contains both the horizontal and
vertical sync pulses.
iii. the differentiated horizontal sync pulses of line frequency are used
to trigger the horizontal oscillator.

9. CONTINUATION………
• HORIZONTAL AND VERTICAL OSCILLATOR SECTION ;
i. vertical section consists of vertical oscillator output amplifier and
vertical deflection coil.
ii. 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.

10. COLOR TELEVISION RECEIVER
• The color tv receiver is similar to the monochrome system expect that
here we have a color demodulator section.

12. 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
It consists of VHF(very high frequency) and UHF(ultra high frequency). it
selects the desired t.v channel.
VIDEO SECTION
It 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.

13. COLOR TELEVISION RECEIVER………
PAL DECODER/COLOR PROCESSING SECTION
It 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)

16. • SOUND SECTION
The output of FM (frequency modulator) detector is processed and the
audio signal is reproduced by the speaker.

17. 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.

18. DIFFERENT STAGES OF TELEVISION RECEIVER

19. • 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.

20. • 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

21. • 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.