In general, a TV receiver circuit consists of:
- IF Video
- Video Detector >> detects video signal
- Video Amplifier >> strengthens video signal
- Gb Tube.
CRT (Cathode Ray Tube) Concept
1. How CRT Works
When the cathode emits electrons originating from the video signal with the help of the filament (the filament glows brightly, thus generating heat. This can occur when connected to a voltage, so that the heat that occurs in the filament emits light).
2. Deflection Yoke
Functions to regulate the movement of electrons that slide, so that they can fill the screen with a layer of phosphor.
Deflection yoke is divided into 2 types, namely:
Vertical and Horizontal, both of which are supplied with sawtooth waves so that the electrons that occur are:
- The Vertical Deflection Yoke directs the electron beam from the top to the bottom of the tube monitor.
- The Horizontal Deflection Yoke directs the electron beam from the right to the left side of the tube monitor.
3. Monochrome Ray
It is the original light that comes from the source, so it has not been contaminated by anything, for example a light bulb, where the yellow color is the original color of the filament.
4. Addictive Rays
It is a light whose color has been influenced by the layers of its wrapping. Example: Neon painted red, or neon with colored phosphor.
5. MONOCHROME: R + B + G = WHITE
The result of mixing primary colors will be a bright color, so whatever the color, if it tends to be brighter, it is often called addictive light.
6. SUBTRACTIVE: R + B + G = BLACK
The result of mixing primary colors tends to change to a darker color. Example; mixing colors in paint.
7. Outdoor Screen
Actually, it is no different from the process of making a movie on the big screen, namely: it requires 48 images in 1 second, so it requires 4 rolls of images in a duration of 2 hours. for example, like in making a cartoon film.
8. Focus Formation
- Zoom: increase the percentage of viewing distance,
- Tele, nide, angle: the addition of lenses to the camera determines the focus distance.
9. Diaphragm
The point/object of light reflection produced by the lens and later the light will be forwarded to the lens, that's where the photo burning process occurs, depending on the level of light entering, the brighter, the greater the burning will be, usually the result of large burning is caused by the diameter of the diaphragm which is too wide open so that too much light enters and the photo results will be white.
The position of the shadow in relation to the lens is adjusted by rotating the part with values 11, 4.8, 6.5, 4.5, 3 and to adjust the speed of the flashing diaphragm (in capturing light) is determined by rotating the part of the lens cylinder that is marked 1/1000, 1/500, 1/250, 1/60, the higher the value, the longer the flashing process.
10. Type of Film
hope 100, hope 200, hope 300, hope 400, DIN. The greater the value, the greater the sensitivity to light.