Category: Television System

Color Television Receiver Block Diagram

Color Television Receiver Block Diagram: Figure 17-25 shows the block diagram of a Color Television Receiver Block Diagram, but for simplicity the circuits shown in Figure 17-23 are omitted. Interconnection points are shown on both diagrams, so that there should be no difficulty in reconciling the two figures. It is now proposed to look first […]

Color Picture Tube Working

Color Picture Tube Working: A Color Picture Tube Working requires correct sweep currents, input voltages and drive voltages. Having said this very quickly, it is now a good idea to examine the circuit block of Figure 17-23, to gauge the complexity of those requirements. The Color Picture Tube Working has three cathodes, or electron guns; […]

Color TV Transmission

Color TV Transmission: Having discussed the manner of indicating luminance and the two components of chrominance in Color TV Transmission, it is now necessary to investigate how they may be, modulated and sent in the 6-MHz channel, without interference to monochrome TV. Color Subcarrier and Chroma Modulation: The actual transmission methods used for the chroma […]

Color TV Transmission and Reception

Color TV Transmission and Reception: If color TV had come before monochrome TV, the system would be far simpler than it actually is now. Since only the three additive primary colors (red, blue and green) need be indicated for all colors to be reproduced, one visualizes three channels, similar to the video channel in monochrome, […]

Television Horizontal Deflection Circuit

Television Horizontal Deflection Circuit: The function performed by these circuits is exactly the same as already described for the vertical deflection circuits. There are some practical differences. The major one is the much higher horizontal frequency. This makes a lot of difference to the circuitry used by the horizontal oscillator and amplifier. Another important difference, […]

Vertical Deflection Circuit in TV

Vertical Deflection Circuit in TV: The Vertical Deflection Circuit in TV include the vertical oscillator and amplifier for vertical scanning at 60 Hz and a similar horizontal arrangement for scanning at 15,750 Hz. For either scanning, the oscillator provides a deflection voltage at a frequency determined by its time constants and corrected by the appropriate […]

TV Receiver Synchronizing Circuits

TV Receiver Synchronizing Circuits: The task of the TV Receiver Synchronizing Circuits is to process received information, in such a way as to ensure that the vertical and horizontal oscillators in the receiver work at the correct frequencies. This task is broken down into three specific functions, namely: Extraction of sync information from the composite […]

Monochrome Television Receiver Block Diagram

Monochrome Television Receiver Block Diagram: Monochrome Television Receiver Block Diagram as shown in Figure 17-9, TV receivers use the superheterodyne principle. There is extensive pulse circuitry, to ensure that the demodulated video is displayed correctly. To that extent the TV receiver is quite similar to a radar receiver, but radar scan is generally simpler, nor […]

TV Video Waveform

TV Video Waveform: Blanking – TV Video Waveform voltage is limited to certain amplitude limits. Thus, for example, the white level corresponds to 12.5 percent (±2.5 percent) modulation of the carrier, and the black level corresponds to approximately 67.5 percent modulation. Thus, at some point along the video amplifier chain, the voltage may vary between […]

Sawtooth Waveform in Beam Scanning

Sawtooth Waveform in Beam Scanning: As previously discussed, one complete frame of a TV picture is scanned 30 times per second, in a manner very similar to reading this page. As our eyes are told where to look by our brain, eye muscles, and nerves, the electron beam is directed to move by deflection coils […]