المخطط الصندوقي للتلفزيون الملون .. كتاب التلفزيون الملون والعادي

4-1 The color TV box diagram: With us in a previous chapter, the monochromatic TV box diagram (black and white) and by comparing the color device box diagram Figure (2-4) with the
It differs, and it is monochromatic. We find that most of the phases and circuits work similarly, especially since both of them receive the monochromatic signal and the colored signal, so they process it in their own way so that it appears on the screen? In monochromatic black and white (whether the signal is mono or colored, and it appears on the color screen in color if the program is colored, and in black and white if the program is monochromatic - this is what is called familiarity or matching - so that no device loses its effectiveness and work, whether it is old or old Recently, it is natural that the color circuits must be more accurate and more complex in design, and the additional circuits that are not found in the monochrome TV are: A - the luminance or brightness amplifier L, which acts as an amplifier for the visual signal after it has left the detector stage B - the decoder unit It is according to the color television system (PAL - SICAM or NTSC), and its function is to receive the visual signal after it is detected in the visual detector, and it separates the color signal and the color synchronization signal from it, and analyzes these signals to obtain from them the basic signals (RGB) or (ER, EG, E) and these symbols denote However, its signals have been subjected to gamma correction in the transmitter, and the three-electronic cannon color screen valve forms the colored image by projecting these signals and the luminance signal (Y) on the three networks and the cathodes. The decoding stage contains the color matrix. On the delay line, and on the electronic switch control unit - (in the SECAM system) (C) the color screen valve, which is fundamentally different from the monochrome screen valve. It consists of three electronic launchers distributed linearly or triangularly. Each launcher deals with a signal of one of the three colors red - green - blue. As for the screen, it is coated with phosphorescent materials in the form of very large triple dots - and each of them gives one of the primary colors. The launcher beam directed to it. There is a screen mask that confines the beam to pass through its specified points.

D - the kinetic convergence unit: it works to project the rays of the three launchers emanating from the airstrips onto a triple
Just one of the three phosphor colored dots on the surface of the screen. If the convergence unit fails to function, then colored edges will appear on the edges of the borders of the photographed objects, and the colors will mix and become difficult to distinguish, and the colors will not appear realistic and correct.
Figure (4-3 ) .
There are two types of convergence:

1- Static convergence: It is the collection of rays to fall on one triple of bright points in the center of the screen when there is no horizontal or vertical deviation. Figure (4) - (4) shows the method of adjusting static convergence, and we will explain this in a later chapter

2- Kinetic convergence: which is achieving the convergence of the three rays on each trio of luminous particles in all parts of the screen. Figure (4) - (4). That is, checks that all scan fields of the three launchers match. Otherwise, color differences appear at the edges of the screen, especially. Kinematic convergence has special coils located on the neck of the color screen valve behind the deflection coils. It is fed from the horizontal and vertical deflection circuits with currents that have the form of an asymmetrical parabola.
E. High voltage regulator: Although the high voltage stage also exists for monochrome television, this high voltage must be more regular and stable and reach about (25) kV or more. This stage is linked to the horizontal deviation stage, which gives the high voltage Initial, then this voltage is multiplied in the triple multiplier or the (Cascade) circuit, and then this high voltage is applied in a rectifier diode.
Private and up to screen elevator.