In recent years, all kinds of audio and video equipment spring up like bamboo shoots, but the development of TV dimming system is relatively backward, so the study of dimming system is particularly important.

Light is the life of television art. Dimming system is safe and reliable, is a strong guarantee to shape the objective world with light. Any professional dimming system, its power is very large, a single bulb is 5kW or even 10kW, and a performance can be thousands of bulbs. Thus, the total power consumption of a dimming system is staggering. Therefore, the efficiency and heat dissipation of the dimming system are very important, which is the key to maintain the reliability of the dimming system for a long time.

Dimming equipment has experienced four generations: the first generation for resistance dimmer.

The second generation of transformer dimming equipment. The third generation is the electromagnetic amplifier type dimming equipment. The fourth generation is SCR dimming equipment. The first generation was the least efficient and the fourth the most efficient.

If the efficiency of dimming system is not high, its own power consumption is quite considerable. Assuming its efficiency is 96 (which seems to be a very good number), when it wants to push a 6kW load, its power consumption is already: 6 (100-96) =0.24kW and assuming a dimming cabinet has 60 6kW loads, then its total power consumption is as high as: Therefore, it is very important to improve the efficiency of the dimming system. It not only reduces the temperature rise of the dimming cabinet (because the temperature rise is proportional to the power consumption), but also reduces the power consumption, thus reducing the operating cost. At present, the more advanced dimming system uses the latest solid switch and high efficiency choke, its efficiency is up to 98, reducing the great interference caused by the sharp rise of current caused by non-100 dimming. (SCR adjusts the voltage by changing the on-angle, and its on-time is only about 1 second. This current waveform is actually a pulse with a very steep front edge.) However, even a highly efficient dimming system, the performance and design of the cooling system is still very important. Even if the efficiency of 98, for example, its own power consumption is still as high as 7.2kW. In order to effectively exhaust such a large power consumption outside the system, to keep the internal components of the system working in a reasonable temperature environment, the reasonable design of the cooling system cannot be ignored.

At present, the world's popular cabinet cooling system has three kinds: forced air supply, forced ventilation and intelligent ventilation.

(1) Forced air supply

This cooling system is to install the blower at the bottom of the cabinet, so that the fresh air from the bottom of the cabinet into the accelerated blowing up, so as to take away the heat generated by the SCR.

The advantage of this approach is high efficiency, with a small fan can put a large number of tropical away. Its disadvantage is that the cold air pumped from below is constantly heated by the power consumption of SCR on the way up, so the temperature of the SCR at the top is much higher than that at the bottom, resulting in the reliability and life of the SCR at the top decline.

(2) Forced convulsions

The design of this system is to install the exhaust fan (newly constructed in the preset role of the fan system library) on the top of the cabinet.

Through proper process design, fresh air enters from the front of each SCR, and then exhausts hot air out of the cabinet by pumping air.

This method through precise design (fluid dynamics) and rigorous process control, from the top to the bottom of each SCR can achieve roughly the same air intake, so that each SCR can operate in an acceptable temperature range, ensuring the reliability of each SCR.

But this design also has a disadvantage, that is, the wind resistance is larger, the need to increase the power of the fan, so the noise is larger.

(3) Intelligent wind

In general operation, the dimming system will rarely be fully loaded, so the amount of air required can be relatively reduced. Intelligent air pumping is based on this theory, by detecting the temperature rise in the cabinet, and then deciding the amount of air pumping, in the general operating environment, the fan only needs to run at a low speed, the noise is relatively reduced, but when the load increases, the fan will accelerate accordingly. In this way, not only retains the advantages of forced pumping, but also solves the disadvantages of high noise.

Finally, it is worth mentioning that although there is a high dimming efficiency and good cooling system, but dimming system is always a great power electrical system. High temperature and the occurrence of arc ignition phenomenon is impossible to avoid completely. Only on the basis of high efficiency and good heat dissipation, supplemented by necessary high temperature and fire prevention measures (such as the use of high temperature flame retardant line), can ensure the safety of the dimming system.