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# 44

1 - High grade ceramics or glass are used for the substrate, to ensure good heat dissipation and electrical performance; various sizes of blanks are used according to the rated power and style of resistor to be manufactured.

2 - The metal film (NiCr) is deposited on the substrate using a vacuum evaporation process at high temperature. In special circumstances NiCu films are deposited electrolytically. The tin oxide film(Sn02) is deposited on the substrate using an evaporation process at high temperature. The carbon film (C) is deposited on the substrate using a hydrocarbon thermal cracking process.

3 - Metal cups are force fitted on the end of the coated substrate which give minimum contact resistance even in the most severe environments.

4 - The final resistance value is achieved by cutting a helical groove in the film (mechanically or by laser beam). Statistical methods are used to maintain process control.

5 - The leads are electrically welded to each cup. The lead material is high conductivity copper, coated with lead alloy to ensure good solderability.

6 - The resistors are encapsulated to give protection from the environment. Depending upon the style they may be encapsulated in lacquer, high temperature cement or by moulding. Special coating techniques are employed in SMID versions to facilitate reliable mounting.

7 - Each resistor is marked with a colour code or print mark to show resistance value and tolerance. Some types are also marked to show model and temperature coefficient.

8- Most standard resistors are available taped in boxes or on reels. SMID's are taped on reels or are available bulk packed.

Vishnay - Draloric

Picture1	Picture2
Picture3	Picture 4
Picture5	Picture 6
Picture 7	Picture 8

Note: the pictures are NOT in the order of the text (See Exercise 1)

UNDERSTANDING THE TEXT

1 Read the text and give each paragraph a title .

Choose from : a/ cupping, b/ encapsulation, c/ lead attach, d/ marking, e/ packaging, f/, resistive film g/ spiralling, h/ substrate.)
and match each paragraph with the corresponding picture.

 

Paragraph	1	2	3	4	5	6	7	8
Picture
Title

2 Analyse the following difficulties

a. Pick up the conjugated verbs.
Are they active or passive ?

b. Pick up the ING forms.( § 1,2, 4,6)
Which ones are used to form prepositions or linking words ?
Which one(s) express(es) means ? (Note that, in this case, they can be found with or without a preposition. Which one?)
Which one(s) is (are) a noun?

c. Look for occurrences of 'to' in para 1,4,5,6,7 and fill in the table.

c. Pick up the compound nouns and adjectives.

3 Vocabulary

a. §1 blanks : 'faux ami', it is not synonymous of white.

b. § 5 lead : is it a verb, an adjective, a noun ? What does it mean here : a heavy metal (=du plomb)? a wire (= un conducteur )? Mind the prononciation : plomb [led], conducteur [li:d] (from the verb to lead).

c. Wordbuilding : §5 solderability. Is it a noun or an adjective ? What is the root word ? As in French, though more usually, -ABLE and - ABILITY are used to coin new adjectives and nouns. Can you think of other words built in the same way ?

d. Give the adjective and the noun (Fill in the table)

LANGUAGE STUDY

1 Expressing time (before, after)

a. Look at the examples : (§ 2 and 3) After / once / when the film has been deposited (note the present perfect), the resistor is cupped. " Look at the shorter forms : After (or before) coating, the resistor is cupped - When / once coated, the resistor is cupped. Note that you have when / once + ED ( past participle) whereas you find after / before + ING .

b. Do the same with the other steps of the manufacturing process. (Use long and short forms.)

2
a. Study the examples. They use high grade ceramics to ensure good heat dissipation. Using high grade ceramics ensures good heat dissipation.

b. Give the other form :

• Employing various sizes of blanks allows to manufacture various types of resistors.
• They force-fit metal cups to reduce contact resistance.
• They use statistical methods to help maintain quality.
• Using high conductivity material ensures good solderability.
• They encapsulate the resistors to give protection from the environment.
• They mark each resistor with a code to show its resistance value.

3 "to be to" expressing obligation.

a. " the rated power of resistor to be manufactured " (§1). This is a short form for : " the rated power of resistor which is to be manufactured ". Is to (be + ED) [= past participle], is approximately equivalent to must (be + ED) (= The rated power of resistor which must be manufactured = … de la résistance à fabriquer / qui doit être fabriquée.)

b. Recast with to be to.

• Special care must be taken when the temperature rises above 50°C.
• The transformations which must be carried out require heavy investments. (Short form.)
• The batteries must be removed if the unit must remain unused for a long time.
• If the appliance must be used for work not specified, make sure that…
• The products which must be shipped overseas are carefully packed in containers. (Short form.)

4 Most - most of the…

a. Compare : " ø resistors are often taped in boxes >> Most resistors are taped in boxes. " The resistors produced by this firm are often taped in boxes >> Most of the resistors produced by this firm (= most of them) are taped in boxes.

b. Look at the table :

Technical Characteristics

c. Use most or most of as in the examples above.

• "The power rating of resistors decreases at 70°C.
• They give maximum power at temperatures well below 70°C.
• The firm's products can withstand 200V at least.
• The insulation voltage of these products is over 700V.
• The thermal resistance of resistors is lower than 150 K/W.
  
• The axial resistance of the resistors shown in the list is over 30N.
• Resistors weigh between 0.14 and 0.31g.
• They weigh less than 0.40g.

5 Comparatives and superlatives. Refer to the table above (exercise 4b):

a.
(i)When you compare two persons / things or two groups of persons / things -for instance one component compared to all the others (considered as a whole) or compared to another one- do you use a comparative (= adjective+ER / MORE adjective ) or a superlative (THE adjective+EST / THE MOST adjective) ?

(ii)When you compare more than two persons / things or more than two groups of persons / things -for instance one component compared to each of the others (considered individually, one by one)- do you use a comparative or a superlative ? Remember that the comparative of 'short' adjectives is -ER (+ than), and 'long' ones MORE (+ than) ; the superlative of 'short' adjectives takes -EST and 'long' ones take THE MOST.

(iii) Which comparative would you use to say that two components have the same quality ? e.g. (i)The power rating of #SMA0204 is lower than the power of #SMA0207 - (ii)The power rating of #SMA0204 is the lowest in the range - (iii) - The power rating of #SMA0204 is not so /as high as the power of #SMA0207

b. Say whether two or more than two components are compared , and consequently whether you would use a comparative or a superlative: SMA0204 and SMA0309; SMA0309 and each of the others; SMA0309 and (SMA0204 + SMA0207); (SMA0309 + SMA0411) and each resistor of the range.

c. Compare the features of the resistors shown in the table. You can use : high / low ; resistant ; light / heavy ; enduring, and other adjectives.

6 Translate into English

• Le choix du film à déposer dépend du type de composant à fabriquer.
• Utiliser des méthodes statistiques assure un bon contrôle qualité.
• La résistance est marquée d'un code couleur avant d'être emballée.
• La plupart des résistances que cette entreprise fabrique sont vendues en boîtes ou en rouleaux .

7 Write a structured account of the manufacturing process.
Use time markers ( first, then, finally and those studied in exercise 1) to show the chronological sequence of operations. Do not copy whole sentences from the text.

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