PPT on electronic engineering

1. Color TV
Pattern
Generator
BY
SHASHWAT REVDANDEKAR
SAMARTH SHARMA
BICHITRA PATRA

2. Description
It is signal generator which outputs predetermined video waveforms.
It also gives the various signals used in synchronization of television devices.
The pattern generator is useful for finding faults in TV sets.
Irrespective of the specific type the output of a video generator will usually contain synchronization
signals like the horizontal sync and vertical sync pulses (in analog).
The Composite Video Signal Generators will also include a colorburst signal in the output along with
the above mentioned output signals

3. Structure of a video signal
The video carrier signal is demodulated to give a composite video signal(as shown in figure-1).
This output signal has 3 basic signals:
Luminance Signal(brightness)
Chrominance Signal(color)
Synchronization Signals
The monochrome signal is similar to the color one except the Color Burst and Chrominance Signal (as
shown in figure-1) are not present

4. Figure-1: A typical composite video signal

5. Figure-2: Circuit diagram of single IC TV pattern generator
The circuit uses Hex Schmitt Inverter IC CD40106

6. Features
Auto generated composite video signal
Standard & stable colour composite video signal
14 standard patterns
Check pattern
Horizontal bar pattern

7. Uses
In general the pattern generator is used to find faults in television sets; some standard patterns used to test
are as follows:
Patterns provide video and RF modulated signals for alignment
Colour bars are used to color settings
Horizontal line, vertical line and circle patterns are used for Raster, Geometric and Linear adjustments
White pattern is used for white balancing
Apart from this it is used for educational purposes

8. Variants
Even though there are a lot of tv pattern generators available readily, there are some generators
whose generated pattern cards are widely popular
Phillips (PM 5540, PM5544, PM 5644)
Grundig VG 1001(FuBk)
SMPTE (Color Bars)
Snell and Wilcox (Zone Plate)

9. Phillips PM5540
Some of the widely popular test cards
Phillips PM5544 SMPTE Color Bars

10. Thank You!