- •Unit 13. Junction Transistors Language Work
- •The Complex Subject
- •The Complex Subject
- •1. Fill in the table:
- •2. Here are some suffixes to make an adjective. Translate them into Russian.
- •4. Divide the words into four columns according to their part of speech (verb, noun, adjective, adverb).
- •5. Put in the missing words, using the words from the table above:
- •6. Choose the appropriate English equivalents.
- •7. Read and translate word-combinations starting from the first component:
- •8. Translate the following sentences into Russian, paying attention to The Infinitive.
- •9. Translate the following sentences into Russian paying attention to The Infinitive.
- •10. These two sentences have a different structure but the same meaning. Change the structure of the sentences below so as to keep their meaning unchanged.
- •12. Choose the appropriate equivalents.
- •13. Translate the following sentences paying attention to The Infinitive.
- •15. Choose the correct translation for the underlined part of the sentence.
- •16. Match the beginnings of the sentences with their ends. Pay attention to the verbs used with the Complex Subject.
- •17. Choose the sentences with the Complex Subject, translate them into Russian.
- •19. Choose as many words from the table оf ex. 1 as you can and form sensible sentences with the Complex Object/Subject.
- •Specialist Reading
- •20. Read the text ‘Junction Transistors’ only once. How much can you remember? Answer these questions without additional reading.
- •If you failed try to answer these questions again after doing the exercises given below the text.
- •21. Read the text again and complete the sentences.
- •22. Match the terms in Table a with their definitions in Table b
- •Speaking
- •24. Divide into 2 groups. Group 1 translates Extract a and group 2 – extract b of the text with a dictionary in writing.
19. Choose as many words from the table оf ex. 1 as you can and form sensible sentences with the Complex Object/Subject.
For example:
The sensitivity of the detector is said to be can be increased.
Specialist Reading
20. Read the text ‘Junction Transistors’ only once. How much can you remember? Answer these questions without additional reading.
Can you define the P-N-P transistor?
What can you say about the characteristics of the various types of junction transistors?
What does the emitter-base constitute?
Can you give the description of current flow in a transistor?
What are the functions of the ‘emitter’ and the ‘collector’?
If you failed try to answer these questions again after doing the exercises given below the text.
Transistors are an extension of the semiconductor diode. The P-N-P transistor is a junction transistor formed by sandwiching (помещать) a very thin strip (полоса) of N-type silicon between two ‘wide’ strips of P-type silicon.
In P-N-P transistor (Fig.1) three leads are brought out from individual metallic plates which contact with the respective (соответствующий) semiconductor crystals.
The geometry of junction transistors differs depending on the method of construction the junction. Moreover, the characteristics of the various types of junction transistors depend on the method of fabrication.
Fig.1. The P-N-P transistor
Refer to Fig.1. The P wafer (пластина) on the left is designated (обозначать) the ‘emitter’, the N wafer in the middle – the ‘base’ and the P wafer on the right – the ‘collector’. The base is about 1 mm thick. For purposes of biasing the transistor may be considered as two diodes.
Fig.2. The operation of a P-N-P transistor
The emitter-base constitutes one diode, the collector-base the other diode, the collector-base the other diode. When used as an amplifier, the transistor is biased as shown in Fig.2. The emitter-base is biased in the forward or low-resistance direction; the collector-base is biased in the reverse or high-resistance direction by collector battery.
Holes are the majority current carriers in the emitter-base diode, and they emanate (исходить) from the the P-type emitter. The presence of the P-type collector and its connection to the negative terminal of collector battery radically alter (изменять) the path (путь) of hole-current flow. Only a small percentage of holes emitted by the emitter combine with the electrons in the base. The other holes (about 95 percent) pass through the very thin base crystal and are attracted to the negative battery terminal on the collector.
The emitter-collector circuit is extremely completed through the two batteries connected in series-aiding (последовательно). From this description of current flow in a transistor it is clear that the emitter-base current carriers, that the emitter-base current is very small, and that the emitter-collector current is high. It may be seen also that changes in emitter-base bias will result in changes in emitter current. Thus, an increase in forward bias will result in an increase in emitter current and hence in collector current. Base current will increase or decrease very little when emitter current increases or decreases. It is evident therefore, that collector current may be controlled readily by changes in emitter-base bias. The designations (обозначение) ‘emitter’ and ‘collector’ may now be readily associated with their functions.
A junction transistor may also be made with an N-P-N configuration.