Lession 8 [Autosaved].pptx

8/10/2019 Lession 8 [Autosaved].pptx

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Giao tiep va am phan trong kinh doanh quoc te

Lession 8: Special Machines


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Lession 8: Special MachinesoinLessiont

Template

Teacher: H Ch Kin

Group 10Template


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Phan Vn Dng 11082401

V Cng Ngha 11232331

H Vnh Trnh 11235911

Phan Thnh Li 11250941

Group 10

L Anh Qun 11292581


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New words1

Translate2

Exercise3

Video4



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stepper motor : ng c bcinteract : tng tc

shaft : trc quaypulse: xungservo motor: ng c secvo (ng c tr ng)openloop: vng hdrive circuitry: truyn ngversatile: ph bin


I. New words


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Reading passage 1:

Stepper motors

http://www.graphicmail.com/sendlink.asp?HitID=0&SiteID=2370&EmailID=0&Link=http://www.orientalmotor.com/in_motion/stepmotor_diagram_0505.htm


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Closely related in design to three-phase AC

synchronous motors are stepper motor, where an

internal rotor containing permanent magnets or a large

iron core with salient poles is controlled by a set of

external magnets that are switched electronically

Loi gn gi trong thit k cho ng c ng b

xoay chiu ba pha l nhng ng c bc, loing c m roto bn trong bao gm nam chmvnh cu hoc li st ln vi c cc li c iukhin bi mt b nam chm bn ngoi, b ny

th c ng ngt kiu in t


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Eng

Viet

ng c bc l mt loi ngc c bit n di chuyn nhngbc ring bit m thngthng l 0.9 mi bc

A stepper motor is a special

kind of motor that moves in

individual steps which areusually .9 degrees each


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Each step is controlled by energizing one or

more of the coils inside the motor which then

interacts with the permanent magnets

attached to the shaft.

Mi bc c iu khin bng cch cp

in cho mt hoc nhiu cun dy bn tronhng c, sau nhng cun dy ny tngtc vi nam chm vnh cu gn lin vi trc

quay


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Turning these coils on and off in

sequence will cause the motor to rotate

forward or reverse.

Vic ng ngt nhng cun dy ny

theo trnh t s lm cho ng c quaytheo chiu thun hay ngc


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Thi gian tr gia mi bc xc nh tc ng c


The time delay between each step determines

the motor's speed

Steppers can be moved to any desired position

reliably by sending them the proper number of step

pulses and stepper motors are rated by the torque

they produce

Cc bc c th c di chuyn n bt k v tr mongmun no mt cch tin cy bng vic truyn cho chngmt s xung bc thch hp v ng c bc th c

nh gi bi momen m chng sinh ra


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Eng

Viet

t c momen nh mc th

nhng cun dy bn trong ng cphi mang dng nh mc trong sutmi bc quay


To achieve full rated torque, the coils

in a stepper motor must reach their

full rated current during each step


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Nhng ng c inng b s dng

nhng vt liu tmm ( c mt li) ckh nng to ramomen ngu lc duy

tr v tr m khngtruyn ng v in

Synchronous electric

motors using soft

magnetic materials(having a core) have

the ability to provide

position holding

torque while notdriven electrically.



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Khng ging nh nhng ng c secvo, nhng

ng c bc c th c s dng vng h mkhng cn ti nhng b m ha c tin kim trav tr ca n


Unlike servo motors, steppers can be used "open-loop"

without the need for expensive encoders to check their

position

Stepper motors are much more cost-effective

than servo systems due to their simplifiedcontrol and drive circuitry

Nhng ng c bc c chi ph thp hn hthng secvo do bi s n gin ha trong iu

khin v truyn ng ca chng


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There are no brushes to replace in a

stepper motor, eliminating the need

for maintenance.

Khng c chi than thay th trong

ng c bc do loi b c nhucu bo tr


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Even though a stepper motor system can notachieve the speed of a servo motor system, their

ease of use allows them to be the preferred

solution for many of today's computerized motion

control systems.

Mc d mt h thng ng c bc khng th t

c tc ca mt h thng secvo, tuy nhinvic s dng chng mt cch d dng cho phpchng tr thnh gii php c a thch chonhng h thng iu khin chuyn ng c

my tnh ha ngy nay.


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The applications: computer controlled steppermotors are one of the most versatile forms of

positioning systems, particularly when part of

a digital servo-controlled system

Nhng ng dng: ng c bc c iu

khin bng my tnh l mt trong nhngdng ph bin nht ca cc h thng iukhin v tr, c bit khi n l mt phn ca

h thng iu khin secvo bng s


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Work in group

?

Structure

of stepper

motor

The

operation

of stepper

motor

How to

control

stepper

motor

Aplication

of stepper

motor

Compared

to servo

motor


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Structure of stepper motor1

Stepper motor has an internal rotor containing permanent magnets

or a large iron core with salient poles is controlled by a set of

external magnets that are switched electronically.

2 The operation of stepper motor

A stepper motor is a special kind of motor that moves in individual

steps which are usually .9 degrees each. Each step is controlled byenergizing one or more of the coils inside the motor which then

interacts with the permanent magnets attached to the shaft. Turning

these coils on and off in sequence will cause the motor to rotate

forward or reverse.


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How to control stepper motor3

Steppers can be moved to any desired position reliably

by sending them the proper number of step pulses

4 Aplication of stepper motor

Computer controlled stepper motors are one of the mostversatile forms of positioning systems, particularly when

part of a digital servo-controlled system


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5 Compared to servo motor

Compared to servo motor,steppers can be used "open-

loop" without the need for expensive encoders to check

their position, more cost-effective than servo systems,

there are no brushes to replace and a stepper motor

system can not achieve the speed of a servo motor

system, but they are easy for use


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Reading passage 2:

Brushless DC motors



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brushless DC motor: ng c mt chiu khng chi thanHall effect: hiu ng Hall

drive electronics : mch truyn ng in tpulse: xungvariable frequency: b bin tnbearings: vng bi

RF noise = radio frequency noise: ting n tn s v tuyn


I. New words


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Midway between ordinary DC motors

and stepper motors lies the realm of

the brushless DC motor

Nm gia ng c mt chiu thng thngv ng c bc l lnh vc ca ng c mt

chiu khng chi than.



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Built in a fashion very similar to stepper motors,these often use a permanent magnet external rotor,

three phases of driving coils, one or more Hall effect

devices to sense the position of the rotor, and the

associated drive electronics

C cu to rt ging vi ng c bc, nhng ng c

ny thng dng 1 roto nam chm vnh cu bao bnngoi, 3 pha ca cun dy truyn ng, 1 hay nhiu thit

b hiu ng Hall nhn bit v tr ca roto v mchtruyn ng in t lin quan



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The coils are activated, one phase after the

other, by the drive electronics as cued by

the signals from the Hall effect sensors.

Nhng cun dy cng c kch hot ln lttrong tng pha mt bi mch truyn ng in tnh c khng ch bi nhng tn hiu t cc

cm bin hiu ng Hall.



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In effect, they act as three-phase synchronous

motors containing their own variable frequency

drive electronics

Thc t, chng c vn hnh nh ng c ng b 3pha c mch truyn ng in t bin tn ring



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Brushless DC motors are commonly used to drive

fans, the spindles within CD, CD-ROM (etc.)

drives, and mechanisms within office products

such as laser printers and photocopiers


Nhng ng c mt chiu khng chi than ththng c s dng truyn ng qut, trcquay bn trong ca nhng a CD, CD-ROM(v.v..), v c cu bn trong ca nhng thit bvn phng nh my in laze v my photocopy.


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Eng

Viet

Chng cng c s dng nhiu

trong nhng my bay m hnhin hiu sut cao


They also find significant use in

high-performance electric model

aircraft


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They have several advantages

over conventional motors:

Chng c mt vi u im hnhn so vi ng c thng thng


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Compared to AC fans using shaded-pole

motors, they are very efficient, running

much cooler than the equivalent AC motors

So vi qut AC dng ng c cc n,chng rt hiu qu, chy mt hn ngc AC tng ng.



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This cool operation leads to much-

improved life of the fan's bearings

iu ny lm tng tui th vng bica qut


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Without a commutator to wear out, the life

of a DC brushless motor can be

significantly longer compared to a DC

motor using brushes and a commutator

Khng c c gp, tui th ca ng c mtchiu khng chi than c th ko di ngk hn so vi ng c mt chiu c chi

than v c gp.



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Commutation also tends to cause a great deal ofelectrical and RF noise; without a commutator or

brushes, a brushless motor may be used in

electrically sensitive devices like audio equipment

or computers


S o chiu cng gy ra nhiu in v cao tng;do khng c c gp v chi than, ng c khngchi than c th c s dng trong cc thit bin nhy cm v in nh thit b audio hoc mytnh.


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The same Hall effect devices that provide thecommutation can also provide a convenient

tachometer signal for closed-loop control (servo-

controlled) applications

Cng nh cc thit b hiu ng Hall to s omch cng c th cung cp 1 tn hiu o tc gc

thun tin cho cc ng dng iu khin vng kn( iukhin secvo)



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The motor can be easily synchronized to

an internal or external clock, leading to

precise speed control

ng c c th d dng ng b hang h bn trong hoc bn ngoi an s iu khin tc chnh xc.



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Modern DC brushless motors

range in power from a fraction of a

watt to many kilowatts

ng c mt chiu khng chi

than hin i c di cng suttng vt t di 1W n vi KW


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Answer the question

?


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Add Your Text

Add Your Text

Add Your Text

Add Your Text

2.What kind of magnet does

The DC brushless motor

Use?3.What are the advantages of DC

Brushless?

4.In which field, the

Applications of DC

Brushless are being

Used?

?

1. Do the structures of the

DC brushless have the same

structure of stepper

motor?Give more details.



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Yes, they do.These often use a permanent

magnet external rotor, three phases of drivingcoils, one or more Hall effect devices to sense

the position of the rotor, and the associated

drive electronics

1


.


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.

The DC brushless motors use a

permanent magnet2


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.

They are very efficient, running much

cooler than the equivalent AC motors, thelife oh them longer, may be used in

electrically sensitive devices, leading to

precise speed control

3


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