Computers are created based on designs taking into account expected of them technical requirements. The variety of applications and computer classes makes distinguishes great quantity and specifications: the dimensions, capacity, cost, protection from external influences, etc. Each of the requirements in some way should be taken into account in designing structures. From the entire set of technical requirements affects the quality of constructions.
Specifications divided into private, relating only to a particular computer and its parts, and general.
General specifications for the computers and equipment are determined by GOST 16325 - 76, GOST 21552 - 84, GOST 20397 - 82, etc. The general technical requirements are divided into several related groups: 1) the functional characteristics, and 2) for resistance to external factors affecting 3) to the Radio 4) Power, the electric strength, insulation resistance and security; 5) to ensure ease of operation, 6) on the use of component elements; 7) to design 8), labeling, packaging, transportation and storage; 9 ) To NONINFRINGEMENT.
Depending on the characteristics of emerging products and content range of groups claims may specify. The biggest influence on the design of computers have the following groups of claims.
* Requirements for the functional characteristics. This group includes requirements for the appointment and parameters characterizing the basic functions (such as performance computers, the time of the operation, the bit RAM, accuracy, etc.). Structures of technical means to build facilities, computer networks, must also possess the technical, software, information and interoperability, which will determine the appropriate element and constructive framework.
* The requirements for resistance to external factors. The influence of external factors largely determine the possibility of normal functioning of computers. For example, temperature changes affect the parameters of IMS and ERE: under certain boundary temperature (plus and minus) performance computers could be compromised. In addition, increased operating temperature reduces their reliability. Fluctuations in temperature can result in mechanical construction sites to change the type of crops, causing a weakening of attachment, thermal stresses. Low temperature worsens strength characteristics of materials, the elasticity of elastic elements.
Reducing atmospheric pressure adversely affect the conditions of heat sink designs in the computer that is connected with many violations of the normal functioning of computers, which causes an increase in temperature. Increased humidity can cause corrosion and structural parts, which is particularly conducive to the existence of active substances in the atmosphere, solar radiation, dust and sand. Reduces insulation resistance between galvanically not bound with chains and thus also violates the working computer.
Since there is a risk of failure of the equipment under the influence of the above factors, the process of developing computer is designed to choose the components, materials and structures, which together would ensure the sustainability of technical computer to external shocks given the intensity.
Usually on the resistance to external factors affecting the technical means computers are divided into groups or categories. Thus, the resistance to climatic factors in the operation of equipment fixed general-purpose computer (such as a unified system of computer products) are divided into groups according to the data specified in the table. 1.
Other tech computer equipment intended for the creation of automated control systems, as well as embedded in machinery, equipment and appliances (such as the product of computer technology systems of small computers), generally should work more demanding conditions than fixed design. In this regard, there is established a greater number of groups (categories) of resistance to climatic factors (Table 2).
Normal climatic conditions of exploitation of technology in the computer are: ambient temperature (293? 5) C, relative humidity (60? 15)%, atmospheric pressure of 84 to 107 kPa (630 to 800 mm RT. Art.). Tolerance overheated air inside the product should not exceed more than 20 to a high temperature air moving to cool.
The products of computer technology to be used at various sites used in one or more makroklimaticheskih areas. Climatic impact in these areas are different, so Protection products are in accordance with GOST 15150 - 69.
There are ten main climate performances items:
- U - for a moderate climate with average maximum and minimum operating temperatures 313 and 228 K;
- UHL - for temperate and cold climates, where the absolute minimum air temperature below 228 K;
- TV - for the humid tropical climate, where the combination of temperature equal to or above 293 K, and relative humidity equal to or above 80%, there is about 12 h or more per day for a continuous period of 2 to 12 months of the year;
- TS - for areas of dry tropical climates, where the average annual absolute maximum air temperature above 313 K, which are not assigned to makroklimaticheskomu area with a wet tropical climate;
- T - how to dry, and the humid tropical climate;
- O - for any climate (obscheklimaticheskaya);
- M - for a moderately cold climate (in the seas, oceans or directly on the seashore, if these areas are located north of 30? North and south of 30? South latitude);
- TM - for tropical marine climate with finding products in the seas and oceans between 30? north latitude and 30? S;
- OM - obscheklimaticheskoe marine enforcement for ships with unlimited navigation area;
- V - vseklimaticheskoe execution for land and sea (except Antarctica).
Application climate for the execution of computer technology makes it possible to quantify the full range of design requirements for computer external resistance to climatic influences. The products of computer technology different climatic performances, depending on location during the operation in the air to a height of 4.3 km, as well as land and water to produce the relevant categories of accommodation (Table 3). These categories of accommodation are not subject to the aerial and space vehicles.
In addition to requirements for resistance to climatic influences, the design of computer technology has also brought demands for the sustainability of the impact of mechanical, radiation and other numerical values of these requirements are established standards or in technical terms to specific computer products. For example, rating factors may be made to GOST 16962 - 71, indicating the degree of stiffness. The impact of most mechanical and some climatic factors (thermal shock, dust, sand, insects, etc.) could lead to violations of certain mechanical parts and ERE, threaded connections, and hence to a breach of efficiency equipment. In connection with the mainframe products as packaged must maintain fitness and appearance after the shock loads reoperate with peak impact acceleration of not more than 15 g with the duration of shock pulse 10 ... 15 ms.
* Requirements for the use of component elements. In designs computer necessary, for example, use the element database (IMS, ERE, etc.), materials and coatings allowed to use the relevant lists. Element base should not be used in the treatment and conditions more severe compared to the stipulated in the technical documentation for these items
* Construction requirements. The group claims to determine the most rational decisions constructive framework. Key among them are the following.
The technical means to carry out desirable computer-based systems, the basic structures in the light of a given design basic sizes, using a modular or block aggregate principle. It should make maximum use of standardized design.
Structural framework to provide: the unity of appearance of computer products to meet the requirements of ergonomics and design, unity of design connectors unit; reliability in the work. The design of computer products must guarantee: convenience, access to all replaceable and adjustable elements, the possibility of repair.
Quantitative values of the indicators of technical reliability of computer sets to normal climatic conditions of exploitation under the table. 4. The average lifespan of modern computer products must be at least 10 years.
The group claims the design also includes requirements: on ways of fixing the mounting parts, structural and assembly units, the construction of government, mass products, etc. In particular, design and location of connectors threaded connections are required to allow for convenient use Telephony and telecommunication tools. Nomenclature of rezb be kept to a minimum, and threaded connections capable of being secured against samootvinchivaniya. There are encouraged to develop individual replacement units weighing over 30 kg.
It is imperative that the design of computer provides the organization of serial production, and their short and constructive base was tech. Specific requirements for indicators of technological rationality constructive solutions, as well as indicators of continuity of design.