- •Memorize the words and word combinations and their equivalents.
- •Find the words and combinations of words in the text and translate the sentences containing them.
- •Read and translate the text.
- •Translate the word combinations from the text:
- •Point out the sentences in the text in which the word “to make” should be translated as “примушувати”.
- •Answer the questions.
- •Find the sentences in the text telling you about two problems facing the simple two pole dc motor. Text b Compensation for stator field distortion
- •Make sure that you know these words and word combinations.
- •Read and translate the text.
- •Answer the questions.
- •Text c Dynamo Design Variations
- •Read and memorise the words and word combinations.
- •Permanent magnet motor – двигун з постійним магнитом
- •Read and translate the text.
- •Answer the questions.
- •Listen to the words and word combinations from the text. Pay attention to their meaning.
- •Memorize the words and word combinations and their equivalents.
- •Read and translate the text.
- •Match the words and word combinations (a-e) to the sentences (1-5)
- •Answer the questions to the text
- •Say if the statement to the text is true or false
- •Translate the sentences paying attention to Indefinite Tenses in Active and Passive. Correct the mistakes in the sentences.
- •Text b Basic construction
- •Listen to the words and word combinations from the text. Pay attention to their meaning.
- •Memorize the words and word combinations and their equivalents
- •Read and translate the text
- •Match the words and word combinations (a-e) to the sentences (1-5)
- •Answer the questions to the text
- •Say if the statements to the text are true or false
- •Translate the sentences paying attention to Indefinite Tenses in Active and Passive. Correct the mistakes in the sentences.
- •Text c Principles of operation
- •Listen to the words and word combinations from the text. Pay attention to their meaning.
- •Find the words and combinations of words in the text and translate the sentences containing them.
- •Memorize the words and word combinations and their equivalents.
- •Read and translate the text
- •Match the words and word combinations (a-f) to the sentences (1-6)
- •Answer the questions to the text
- •Define the functions of Participle I and Participle II in the following sentences
- •Say, which of the sentences are in the Active and which are in the Passive Voice
- •Translate the sentences paying attention to the Sequence of Tenses
- •Translate the following Conditional sentences
- •Transformer Text a
- •Read and memorize words and word-combination
- •Make sure that you know these words and word combinations.
- •Read and translate the text.
- •Math the following English words with the Ukrainian ones.
- •Find English equivalents to the words:
- •Translate the word combinations from the text:
- •Answer the questions to the text.
- •Text b Operation at different frequencies
- •Read and memorize the words and word-combinations
- •Be sure that you know these words
- •Read and translate the text.
- •Text c Limitations
- •Make sure that you know these words and word combinations.
- •Read and translate the text.
- •Find the equivalents to the following.
- •Text d Construction
- •Read and memorise the words and word combinations
- •Read and translate the text. Cores
- •Find the equivalents to the folloving English words:
- •Point out English equivalents to the words:
- •Translate the word combinations.
- •Answer the questions.
- •Read the passage about steel cores. Retell it. Text e Windings
- •Listen to the words and word combinations from the text and memorize them.
- •Read and translate the text.
- •Match the English words and word combinations with the Ukrainian ones.
- •Insulation of windings
- •Text g Shielding
- •Supplement Speed control
- •Dc motor starters
- •Shielding
- •Autotransformers
- •Voltage transformers
- •Pulse transformers
- •3 Phase electrical power Transformer
- •3 Phase Transformer Delta and Wye Connections
- •Перелік скорочень
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Be sure that you know these words
adapt – впроваджувати, пристосовувати
application – застосування
fraction – частина
volt-ampere – вольт-ампер
power supply – джерело живлення
impedance matching – узгодження повного опору
circuit – коло (ланцюг), схема
circuit isolation – розв’язка кола (ланцюга)
range – діапазон
power frequency – частота мережі
audio frequency – звукова частота
ratio frequency – радіочастота
cooling – охолодження
distribution – розподіл
rectifier – випрямляч
arc furnace – дугова піч
amplifier output – вихід підсилювача
step-up transformer – підвищуючий трансформатор
step-down transformer – знижуючий трансформатор
isolating transformer – розв’язуючий трансформатор
coil – катушка, обмотка, виток
equal – однаковий, рівний
compensate – компенсувати
variable transformer – регулюючий трансформатор напруги.
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Read and translate the text.
The equation shows that the EMF of a transformer at a given flux density increases with frequency. By operating at higher frequencies, transformers can be physically more compact without reaching saturation, and a given core is able to transfer more power. However, other properties of the transformer, such as losses within the core and skin-effect, also increase with frequency. Generally, operation of a transformer at its designed voltage but at a higher frequency than intended will lead to reduced magnetising (no load primary) current. At a frequency lower than the design value, with the rated voltage applied, the magnetising current may increase to an excessive level.
Operation of a power transformer at other than its design frequency may require assessment of voltages, losses, and cooling to establish if safe operation is practical. For example, transformers at hydroelectric generating stations may be equipped with over-excitation protection, so-called "volts per hertz" protection relays, to protect the transformer from overvoltage at higher-than-rated frequency which may occur if a generator loses its connected load.
Classifications. Transformers are adapted to numerous engineering applications and may be classified in many ways:
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By power level (from fraction of a volt-ampere(VA) to over a thousand MVA),
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By application (power supply, impedance matching, circuit isolation),
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By frequency range (power, audio, radio frequency(RF))
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By voltage class (a few volts to about 750 kilovolts)
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By cooling type (air cooled, oil filled, fan cooled, water cooled, etc.)
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By purpose (distribution, rectifier, arc furnace, amplifier output, etc.).
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By ratio of the number of turns in the coils
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Step-up. The secondary has more turns than the primary.
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Step-down. The secondary has fewer turns than the primary.
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Isolating. Intended to transform from one voltage to the same voltage. The two coils have approximately equal numbers of turns, although often there is a slight difference in the number of turns, in order to compensate for losses (otherwise the output voltage would be a little less than, rather than the same as, the input voltage).
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Variable. The primary and secondary have an adjustable number of turns, which can be selected without reconnecting the transformer.
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Find Ukrainian equivalents to the words:
saturation, skin-effect, over-excitation protection, impedance matching, circuit isolation, rectifier, amplifier output, step-up transformer, step-down transformer, isolating transformer, variable transformer, power frequency.
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Point out English equivalents to the words:
розрахована напруга, надмірний, відношення напруги до частоти, реле захисту, намагнічуючий струм, призначений, прикладена напруга, джерело живлення, компенсувати, звукова частота, радіочастота.
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Translate the word combinations from the text.
Rated voltage applied, hydroelectric power station, higher-than-rated frequency.
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Give the classification of transformers according to engineering applications. Discuss it.
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Speak on the classification of the transformers by ratio of the number of the coils.