Английский язык для судовых электромехаников - [22]

Text

Automatic Voltage Regulators

of the following parts: voltage measuring circuit, amplifier, frequency measuring circuit, synchronizing and triggering circuit, stabilized power supply.

11

8

J

Fig. 5. Automaic voltage regulator. Block diagram: 1 — ciirrent transformer; 2 — fuses; 3 — excitation switch; 4 — AVR unit; 5 — voltage adjuster; 6 — voltage build-up circuit; 7 — thyristor bridge; 8 — compounding transformer; 9 ■—rotating diode bridge; 10 — compounding circuit; 11 — supply transformer

All the above mentioned circuits are mounted on a printed board.

8. The alternator voltage is transformed before it is fed to the printed circuit board via terminals. The voltage is rectified and a proportional voltage is fed to an operational amplifier where it is compared to the reference voltage. The difference voltage is amplified and controls, via a triggering circuit, the firing angle of the thyristors and thereby the exciter current.

9. In case of alternator voltage change, the regulator generates a signal which changes the firing angle of the thyristors until the desired voltage is obtained. A stabilizing filter ensures stable and alternator voltage.

Exercises

1

6

Read the text and write out names of the AVR circuits parts.

2

6

Looking through the text find and read the passages containing the information:

а) о принципе работы регулятора;

б) о заданном и разностном напряжениях;

в) о работе регулятора в случае изменения напряжения генератора переменного тока;

г) о работе цепи измерения частоты.

Read the text paying attention to Gerund.

4 6

Repeat the words after the teacher. Then read them by yourself paying attention to their Russian equivalents.

power factor block diagram

autonomous alternator system

is fed to the AVR unit fuse

exciter switch

reference level actual voltage reference value triggering pulse supply transformer current transformer resistance network voltage build-up circuit

residual

compounding circuit transient protection

AVR circuit

voltage measuring circuit amplifier

frequency measuring circuit synchronizing circuit triggering circuit

stabilized power supply

printed board operational amplifier difference voltage firing angle

— кпд, коэффициент мощности, косинус

— структурная схема (блочная)

— система с автономным генератором переменного тока

— подводится к блоку АРН

— предохранитель

— выключатель напряжения возбуждения

— заданный уровень

— действительное напряжение

— заданная величина

—• включающий импульс

— питающий трансформатор

— трансформатор тока

— цепочка сопротивления

— цепь восстановления напряжения

•— остаточный

— компаундирующая цепь

— защита для переходных режимов

— схема АРН

— измерительная цепь напряжения

— усилитель

— цепь измерения частоты

— цепь синхронизации

— цепь выработки переключающих импульсов

— стабилизированный источник питания

— печатная плата

— операционный усилитель

— разностное напряжение

— угол зажигания

The second class period

5 8 Read the text carefully. Use ex. 4.

6 1

Read the words and point out those of the text:

a) presetting;

b) fuse; c) overflow;

d) feature; e) residual; f) set;

g) amplifier; h) network; i) to modify;

j) counter; k) switch; 1) reference; m) data; n) transient.

Read the words, point out those which deal with the topic “Principle of Operation of AVR” and write them out:

c) to feed

a) load d) switch

b) ship e) factor

f) fuse

g) to obtain

h) level

i) to amplify

j) to permit

k) bridge

l) to convert

m) to equip

n) supply

o) transformer

p) amount

q) sharing

r) power

s) various

t) inside

u)

V)

w)

X)

У)

z)

a')

b')

c')

d')

residual length circuit to provide to feed to couple excitation board elimination to adjust

8 2

Read the word-combinations and point out those with Infinitives: a) permit to obtain; b) we shall speak about; c) is fed to the unit;

d) converted to triggering pulses; e) unit will automatically decrease; f) is made current dependent; g) it must have been a sight; h) I would’ve liked; i) you want the computer to teach you; j) but suppose it goes wrong; k) I’m' bound to make up; 1) what you may call a man’s job;,

m) I’ve just got a job; n) drives are used to heave in.

9 1

Read the sentences and point out numbers of those which deal with the topic “The Principle of Operation of the AVR”.

1. The AVR is especially designed for brushless alternators. 2. The alternator voltage is fed to the AVR unit via fuses and exciter switch.

3. The reference level of the alternator voltage is set by the voltage adjusting, potentiometer. 4. The main parts of the AVR are built as one unit, including voltage build-up circuit and excitation switch. 5. A-c voltage is fed from the alternator via supply transformer to the thyristor bridge. 6. The regulators permit to obtain constant voltage of generators under various amount of load and power factor.

10 25

Home exercise. Read some information on Infinitive constructions with the purpose of its correct translation into Russian.

Особенности перевода на русский язык инфинитивных конструкций