Lecture
From a design point of view, the effects of climatic conditions and mechanical loads are extremely important. Climatic influences are characterized by the influence of temperature, thermal shock, humidity, atmospheric pressure, dust, solar radiation. This should take into account the content in the atmosphere of corrosive substances — sulfur dioxide, chloride and ammonia. For tropical operating conditions, biological factors are additionally taken into account — the influence of mold, insects and rodents.
During operation and (or) transportation, almost all types of radio electronic devices are subject to mechanical stress — vibrations, shocks, linear accelerations and acoustic shocks. Mechanical effects can cause large destructive stresses in the elements of radio electronic devices.
Vibrations are periodic oscillations that occur in the apparatus when in contact with a collar source (installation object, vehicle). Distinguish vibration resistance (functioning of the apparatus in terms of vibration) and vibration strength (opposition of the apparatus to the damaging effects of vibration in the idle state). The parameters of vibration exposure are frequency and acceleration specified in the TOR. A shock is characterized by a pulse duration and acceleration, and a linear acceleration by acceleration.
Acoustic noise occurs in the working engines of an installation facility (rockets, airplanes) and is characterized by sound pressure and a spectrum of sound frequencies.
Accounting for all factors influencing the RES in their design is extremely difficult, requires a large amount of experimental and research work. To simplify this issue, the execution of products suitable for work in different climatic areas, as well as the conditions of placement at the facility are systematized and standardized.
Table 6.1 The main climatic modification of products
Area code |
Execution, climate |
Have |
Moderate |
UHL |
Temperate and cold |
Tv |
Wet tropical |
Vehicle |
Dry tropical |
M |
Moderately cold sea |
Tm |
Tropical sea |
ABOUT |
Climate for sushi |
OM |
All-Climate Marine |
AT |
All-climate performance for land and sea (does not apply to Antarctica) |
Table 6.2 Location category of radio electronic facilities at the facilities
Category |
Characteristic |
one |
Outdoors |
1.1 |
for storage and work in category 4 premises and for short-term work in other conditions, including in the open air |
2 |
Under a canopy and on objects where the rims of *** temperature and humidity are slightly different from the conditions of the open air |
2.1 |
Inside product placement categories 1; 1.1; 2, but with the exclusion of the condition of moisture condensation |
3 |
In closed rooms with natural ventilation without air conditioning |
3.1 |
In irregularly heated rooms (objects) |
four |
In rooms (objects) with an artificial climate |
4.1 |
When air conditioning or partial air conditioning |
4.2 |
Inside industrial heated rooms |
five |
In rooms with high humidity. leading to frequent moisture condensation on walls and ceilings |
5.1 |
Inside products of category 5. but subject to the exclusion of moisture condensation on this product |
Depending on the operating conditions, domestic RES are divided into four groups. In accordance with these groups, the equipment must withstand the climatic and mechanical influences established in GOST 11478-83.
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Design and engineering of electronic equipment
Terms: Design and engineering of electronic equipment