In order for an image to appear on the kinescope screen and the viewer to enjoy their favorite programs, it is necessary to direct an electron beam that runs around its entire area. The principle of operation of a monitor or TV, on which a cathode ray tube serves as a display element, is easier to describe using the example of black and white equipment.
So, the image on the screen is formed by just one point, with a high frequency running hundreds of lines. We see the overall picture due to the inertia of the organs of our vision.
Besides this, in order for the image to be dynamic, a change of frames is also necessary. The electron beam runs line by line from top to bottom and returns again because it is driven by a magnetic field created by the windings of the deflecting system. In order for this to happen, you need to change the current in it with a certain pattern.
The classic TV circuit includes various nodes: power supply, horizontal and vertical scanning, a radio channel, a control unit, a low-frequency amplifier and a color module if the receiver is color. The main element of the horizontal scanning unit is a horizontal transformer. In modern TVs, it is usually combined with a multipliervoltage. Its purpose is to receive sawtooth pulses of electric current, which are fed to the windings of the deflecting system. The voltage multiplier, mounted in the same housing as the horizontal transformer, creates a high, up to 27 kilovolts, accelerating voltage, which ensures the acceleration of electrons in their movement towards the screen mask coated with a phosphor. It, in turn, is fed to the kinescope through a high-voltage insulated input with a so-called “pattern” that protects the contact from breakdown on the case.
A line-scan transformer mounted together with a multiplier (TDKS) has several windings that form additional control signals. These include adjustable focus and the magnitude of the accelerating voltage, as well as the windings for damping the backswing of the beam, which should not be visible on the screen.
So, two groups of windings of the deflecting system provide scanning of the raster vertically (frame, CR) and horizontally (linear, SR). As a result, its shape is very close to rectangular, but does not quite correspond to it. This deviation is due to the difference in the distance that the electrons have to overcome on their way to the mask. The closer to the edge of the screen, the larger it is, and CRTs with flat screens suffer from this defect to a greater extent than their "bulging" counterparts. The line transformer, together with the multiplier and the deflection system, are subject to careful regulation and tuning, after which the distortion becomes minimal.
The requirements for the quality of TDKS are very high, the duration of the correct operation of the entire television receiver depends on it. Line transformers are structurally made in the form of an assembly filled with a compound and cannot be repaired, therefore all internal contacts between the windings must be very reliable.
The CP Node consumes most of the energy used by the TV, up to half of its total.
Like any inductive device, a horizontal transformer has a magnetic circuit that serves as a core on which coils are put on. In order to reduce the size, it is made of a special ferrite with high magnetic conductivity.
For all these reasons, TDKS is the most expensive spare honor after a kinescope, the need for which may arise when repairing a TV.
