GIỚI THIỆU VỀ MẠCH ĐIỀU CHỈNH TỐC ĐỘ ĐỘNG CƠ

7/28/2019 GII THIU V MCH IU CHNH TC NG C

1/56

1

B CNG TH NG

TR NG CAO NG K THU T CAO TH NG

*******************

N MN HC

MN IN T CNG SUT

TI :

MCH THAY I TC V OCHIU QUAY NG C 12V DC

GIO VIN H NG DN :

TNG THANH NHN

SINH VIN THC HIN: NG MINH TML U KIM PHT NGUYN HONG V MAI THI DUY


2/56

2

NHN XT CA GIO VIN H NG DN:


3/56

3

LI NI U

Vi xu h ng gio dc hin nay, hc th phi i i vi hnh. Do ,bncnh vic hc nhng l thuyt c bn trong tr ng lp th i hi hc sinh ,phi bit ng dng nhng g hc vo thc tin ,c vy m i gip chng ta nm btnhng kin thc hc

ng thi cng gip pht huy kh nng nng ng sng to .Nht l i v inhng sinh vin ,hc sinh ngnh k thut , trong c in t- tin hc.

Trong mnin t cng sut nhm chng em c lm mt ti nh l:MCH THAY I TC NG C 12V DC BNG PH NG PHPTHAY I IN P dng Ic 556 .

Tuy nhin , do kin thc ca chng em cn hn chkhng th c p ht ccvn trong ti ny ,do khng thtrnh khi nhng thiu st . R t mong c nhn s ng gp kin ca thy v cc bn .

Xin cm n

Nhm: _ NG MINH TM

_ L U KIM PHT _NGUYN HONG V

_MAI THI DUY


4/56

4

Chng em xin g i li cm n chn thnh n tp th gio vinkhoa IN T -TIN HC TR NG CAO NG K THUT CAO THNG,c bit l s h ng dn v gip nhit tnh c a gio vin T NGTHANH NHN ht lng gip chng em trong qu trnh th chin ti .

chng em cng chn thnh cm n qu thy c trong tr ngCao ng K Thut Cao Thng to nn mng ki n thc cho chngem.

Xin g i li chc s c khe v lng tri n chn thnhn qu th y c


5/56

5

MC LC

CH NG D N NHPI.T VN

II.GII HN TI

III.MC CH NGHIN CU

IV.MC CH YU CU

V.THI GIAN THC HIN

CH NG II: L THUY T MCH CHNH L U

CH NG III:VI MCH NH TH 556I.GII THIU ic 556.

II.MCH A HA PHI N DNG IC 555.

III.MCH A HI N N DNG IC 555..

IV.IC 555 GIAO TIP VI CC LOI TI .

CH NG IV:PHN TCH - THIT K

I.S NGUYN L.. II.PHN TCH THIT K..

1.MCH CHNH L U ..

2.MCH A HI PHI N S DNG IC556

3.MCH N N S DNG IC556

4.CC THNG SCA MCH

III.THI CNG MCH

CH NG IV: KT LUN


6/56


7/56

7

Qua qu trnh nghin cu mch cng to iu kin cho sinh vin h thngli nhng kin thc hc trong b mn in t cng sut qua thy c tmquan tr ng ca mn hc ny, ng th i gp phn nng cao kh nng ng dngnhng g hc ca sinh vin vo thc tin

IV. Mc ch yu c u :Thit k mch in dng thay i tc ng c v o chiu quay

CH NG I I: L THUYT MCH CHNH L U

I. .Khi ni m v ch nh lu:

Mt mch chnh l u l mt mch in bao gm cc linh kin in- in t,dng bin i dng in xoay chiu thnh dng in mt chiu.Mch chnh l uc th c s dng trong cc b ngun cung cp dng in mt chiu, hoc troncc mch tch sng tn hiu v tuyn in trong cc thit b v tuyn. Phn t tcc trong mch chnh l u c th l cc it bn dn, cc n chnh l u thy ngnhoc cc linh kin khc.

Khi ch dng mt it n l chnh l u dng in xoay chiu, bng cchkha khng cho phn d ng hoc phn m ca dng sng i qua mch in, thmch chnh l u c gi l chnh l u na chu k hay chnh l u na sng. Trongcc b ngun mt chiu ng i ta hay s dng cc mch chnh l u nhiu it (2hoc 4 it) vi cc cch sp xp khc nhau c th bin i t xoay chiu thmt chiu bng phng hn tr ng hp s dng mt it ring l. Tr c khi ccit bn dn pht trin, ng i ta cn dng cc mch chnh l u s dng n in tchn khng, n chnh l u thy ngn, cc dy bn dn a tinh th seleni

Cc my thu thanh v tuyn u tin, ng i ta gi l cc my tinh th, dngmt si ru mo hoc mt kim nhn tip xc nh vo mt im trn mt khi

tinh th galena (sunpht ch) to ra mt it tip im, hoc mt b tch sntinh th. Trong h thng sy t kh, cc b pht hin la c th dng. Hai introng mt v bc kn c th sn sinh ra dng in v c th chnh l u c mtdng in xoay chiu, nh ng ch khi chng nhn thy ngn la

II. Mch ch nh lu n a sng


8/56


9/56

9

IV. Chnh lu cu 1 pha c t lc

Cc i t trong mch chnh l u cu t nhin t khi chng b hng, chng ch hng khi in p 300V DC b chp, khi dng qua i t tng cao lm cho i t b ch p hoc t.

- in p AC 220V u vo c hai cc, mt cc tip t c gi tr 0V, cc kc hai pha m v d ng o chiu lin tc. - Khi cc trn c pha d ng, dng in s i t +220V qua i t D2 => quaR ti => qua D4 ri tr v 0V - Khi cc trn c pha m, dng in i t 0V i qua i t D3 => qua R ti =qua D1 ri tr v in p-220V=> Trong mi pha in ch c hai i t mc i xng hot ng, hai i t ktm thi tt.

- Nu mt i t bt k b t hoc c hai i t i din b t th in p ra c dng nhp nh th a cch qung
http://vi.wikipedia.org/wiki/T%E1%BA%ADp_tin:Fullwave.rectifier.en.pnghttp://vi.wikipedia.org/wiki/T%E1%BA%ADp_tin:Fullwave.rectifier.en.png


10/56

10

V. Datasheet cadiode


11/56

11


12/56

12

VI. Datash eet ca ic n p


13/56

13


14/56

14


15/56

15


16/56

16


17/56

17


18/56

18

CH NG III. VI MCH NH TH 556

I. Gi i thi u IC 556:Ic 556 l mt loi phin bn kp ca ic 555 , v vy gii thch nguyn l hot

ng ca ic 556 th ta thng qua vic gii thch hot ng ca ic 555.

Ic 555 v hca n c ng dng r t r ng ri trong thc t c bit trong lnhvc iu khin ,v nu k t h p v i cc linh kin RC th n c th thc hin nhiuchc nng nh nh th , to xung chun , to tn hiu kch , hay iu khin cc linhkin bn dn cng sut nh transistor ,SCR ,triac,

Cc chn ca ic 556 bao gm cc chn sau:

Chn 1 : discharge 1

Chn 2 : threshold 1

Chn 3 : control 1

Chn 4 : reset 1

Chn 5 : output 1

Chn 6 : trigger 1

Chn 7: gound

Chn 8: trigger 2


19/56

19

Chn 9 : output 2

Chn 10: reset 2

Chn 11 : control 2

Chn 12 :threshold 2Chn 13 : discharge 2

Chn 14 : +vcc

Cu trc bn trong c a ic 556:

Cu trc bn trong ic 555:


20/56

20

Hnh .a


21/56

21

1) Cu phn p gm 3 in tr 5k ni t ngun vcc xung masscho ra hai in p chun l 1/3 vcc v 2/3 vcc

2) Opamp (1) l mch khuych i so snh c ng In nhn in pchun 2/3 vcc, cn ng In th ni ra ngoi chn 6. Ty thucin p ca chn 6 so vi in p chun 2/3 vcc m opamp(1)c in p ra mc cao hay mc thp lm tn hiu R(Reset),iu khin flip-flop

3) Opamp(2) l mch khuych i so snh c ng In nhn in pchun 1/3 vcc , cn ng In th ni ra ngoi chn 2. Ty thucin p ca chn 2 so vi in p chun 1/3 vcc m opamp (2)c ng ra mc th p hay mc cao iu khin tn hiu S (Set),iu khin flip-flop

4) Mch flip-flop l mch l ng n kch mt bn .khi chn set cmc in p cao th in p ny kch i tr ng thi ca flip-flop ng Q ln mc cao v ng ra Q c mc th p .khi ng Setang mc cao xung mc th p th mch flip-flop khng itr ng thi khi chn R c in p cao th din p ny kch itr ng thi ca flip-flop lm ng Q ln mc cao v ng ra Qxung mc thp. khi ng Reset ang mc cao xung th p thmch flip-flop khng i tr ng thi

5) Mch output l mch khuych i ng ra tng khuychi dng c p cho ti . y l mch khuych i o c ng vol chn Q ca flip-flop nn khi ng vo Q mc cao th ng ra chn 3 sc mc thp v ng c li

6) Transistor T1 c chn E ni vi in p chun 1,4 v ,l loitransistor PNP, cc B ni ra ngoi b i chn 4 c in p caohn 1,4 v th T1 ng ng dn , nn T1 khngnh h ng g dnmch . khi chn 4 c in tr nh thch h p ni mass th T1 dn bo ha ng th i lm mch output dn bo ha v ng raxung th p. chn 4 cn gi l chn reset c ngha l n reset ic555 bt ch p tnh tr ng ng vo khc . Do chn 4 dng k t thc xung ra s m khi cn. nu khng dung chc nng resetth ni chn 4 v i vcc d trnh mch b reset do nhiu

7) Transistor T2 c cc C d h ni ra chn 7. Do cc B c phn cc b i mc in p Q nn khi Q mc cao th T2 boha v cc C coi nh ni mass . Lc ng ra chn 3 cng mc th p. khi Q mc thp th T2 ng ng dn cc C ca T2xem nh bh.lc ng ra chn 3 mc cao.


22/56

22

Datasheet c a ic 556 :


23/56

23


24/56

24


25/56

25


26/56

26


27/56

27


28/56

28


29/56

29


30/56

30

II. Mch a hi phi n dng ic 555:1. Mch phi n c bn:

Hnh.b

y l mchng dng ic 555 dng lm mch a hi phi n to xung vung

Trong mch ,chn ng ng (Threshold) s 6 c ni v i chn ny (trigger)s2 , nn hai chn ny c chung in p l in p trn tC, so vi in p

chun l 2/3 v 1/3 b i opamp (1) v opamp(2) ,chn 5 c tnh .1uF ni masslc nhiu tn scao c th lmnh h ng n in p chun 2/3vcc

Chn 4 ni v i ngun +Vcc nn khng dng chc nng reset, chn7 x in c ni vo gia 2 in tr Ra v Rb to ng x in cho t to ng x incho t ,ng ra chn 3 cin tr gi i hn dng 1,2K v led biu hin mc inp ra ch c th dng trong tr ng h p tn s dao ng c tr s th p t

VCC

Rb

R11,2K

U1

NE555

3

4 8

5

26

7

1

OUT

R S T

V C C

C V

TRGTHR

DSCHG

G N D

0

D1

LED

0

0,01uF

0

Ra

C2

0


31/56

31

20Hztro73 xung v tn s cao hn 40Hz , trng thi sng tt ca led kh c th nhn bit bng mt th ng . phn tch nguyn l ca mch cn phi h p mchng dng hnh.a v himh2.b.

2. Phn tch m chKhi mi ng in th t n p t 0 ln :- Op amp (1) c V+ < V- nn R c mc th p(R=0)- Op amp(2) c V+ > V- nn ng s c mc cao (S=1)- Mch F/F c ng S=1 ,R=0 nn Q=1 v Q=0 . lc ng ra chn

3 c mc cao- Transistor T2 c VB =0 nnng ng dn v tC np in v i

th i gian n p l :T nap=0.69(Ra+Rb).C

Khi p trn t tng n mc 1/3vcc th opamp (2) i tr ng thi, ng S= 0 .Khi S xung thp th F/F khng i tr ng thi nn in p ng ra vn mc cao

Khi in p trn t tng n 2/3vcc th opamp(1) i tr ng thi, ng R mccao(R=1)

Mch F/F c R=1 nn Q=1 v ng ra chn 3 c in p thp . khi ngT2 dn bo ha v chn 7 ni mass ngn tc np in m phi x in qua RB

qua T2 xung mass . TC x in v i hng s th i gian l :T x=0.69.Rb.C

Khi in p trn t gim xung d i 2/3 vcc th opamp(1) i tr ng thiR=0 . khi R xung mc thp th F/F khng i tr ng thi nn in p ng ra vn mc thp.khi in p trn t gim xung n mc 1/3 vcc th opamp(2) i tr ngthi tc S=1 . nn ng ra chn 3 c mc cao . ng th i T2 mt phn cc nnng ng dn v chm dt giaion x ca t. nh vy mch li tr li tr ng thi ban

u v ti p tc n p ln tmc in p l 1/3vcc ln n 2/3 vcc.Hin t ng trn s ti p din lin tc v tun hon.

L u : Khi m i m in tC s t 0V ln 2/3Vcc r i sau tx in l2/3Vcc xung 1/3 Vcc ch khng xxung 0V .nhng chu k sau ,t s t t 1/3Vcc ln 2/3Vcc ch khng n p t 0 na.


32/56

32

Th i gian tn p l th i gian Vo=+Vcc, led sng . th i gian t x l th i gianVo=0V,led tt.

Th i gian tn p v x c tnh theo cng thc :

Th i gian n p : T n p =0,69.(Ra+Rb)CTh i gian x: T x= 0,69.Rb.C

in p ng ra chn 3 c dng hnh vung v i chu k l :

T = T n p + T x

Do th i gian n p v th i gian xkhng bng nhau (T n p > T x) nn tnhiu hnh vung ra khng i xng . Tn sca tn hiu hnh vung l :

F = 1 / T = 1 / (0,69.(Ra+2Rb).C)

3.Dng sng ra t i cc chn:

Hnh.c

Hnh c l dng in p ti cc chn 2-6,chn 7 v chn 3,trong khongthi gian in p tng l th i gian tn p ,khong thi gian in p gim l th igian tx.


33/56

33

khi kho st dng in p ti cc chn cn l u :khi m i m in th tC s n p t 0V ln n 2/3Vcc ,nh ng khi xch x n 1/3Vcc. tnh chu k ca tnhiu , ng i ta ch tnh cc ln n p sau ch khng xt cc ln np u tin.

Khi tn p th chn 7 cin p cao hn 2-6,nh ng khi t x th chn 7 gimnhanh xung 0V-do T2 trong Ic chy bo ha ch khng gim theo hm s mtrn tC.

4.Mach phi n i xng :

Trong mch phin c bn ,do th i gian n p v th i gian x ca tkhng bngnhau nn dng in p ng ra khng i xng

Ta c: T n p =0,69(Ra+Rb)C

T x=0,69(Rb.C)

cho dng sng vung ng ra i ng i ta c th thc hin bng nhiu cch.

Cch th 1: chn in tr Ra c tr s r t nhso vi Rb th lc saisgia Tn p v T x coi nh khng ng k .iu ny kh thc hin nu lm vic tn s cao .in tr Ra c tr s ti thiu khong vi K th Rb c trs r t l n khongvi trm K .V i cc tr s in tr ny th tn s dao ng khng th cao c.

Cch th 2: Dng diot ghp song song Rb theo chiu h ng nh hnh v .


34/56

34

hinh.c

Khi c diot D ,th i gian tC n p lm diot phn cc thun c in tr r t nh nn coi nh ni tt Rb.

Th i gian np in ca t c tnh theo cng thc :

Tn p =0,69RaC

Khi tC x in th diot c phn cc ng c nn t vn x in qua Rb . th igian x in ca t c tnh theo cng thc :

T x=0,69.Rb.C

Nu chn tr sRa bng Rb th mch s to ra tn hiu hnh vung i xng .

Thc ra ,trong mch in hnh.c khi tnp dng in qua Ra v in tr thun cadiot, nn th i gian n p vn ln hn th i gian xmt t

4.Mch phi n iu ch nh tn s:

Hai yu cu th ng c trong thit k ca mch a hi phi l : _Thay i tn s f m vn gi nguyn chu trnh lm vic (i xng )

_Thay i chu trnh lm vic m vn gi nguyn tn s f.

c th thay i tn sca tn hiu hnh vung ra m vn c tn hiu i xng th

VCC

Rb

R11,2K

D2

DIODE

U1

NE555

3

4 8

5

26

7

1

OUT

R S T

V C C

C V

TRGTHR

DSCHG

G N D

0

D1

LED

0

0,01uF

0

Ra

C2

0


35/56

35

hai in tr Ra v Rb phi c iu chnh sao cho cng tng hay cng gim tr s

.Lc trong mch in c thm 2 bin tr VRa v VRb ghp ni tip nh hnh .d

hnh.d

thay i chu trnh lm vic tc l thay i t l th i gian tn hiu c in p caov th i gian tn hiu c in p th p , hay l th i gian n p v th i gian x ca t nh ng vn gi nguyn tng s (ngha l chu kT bng hng s ).

Hai in tr Ra v Rb phi c iu chnh sao cho khi Ra tng th Rb gim cngmt gi tr thay i .Lc trong mch c thm hai bin tr VRa v VRB ghp nitip nh s hinh.d nh ng hai bin tr c iu chnh ng c h ng.

III. Mch a hi n n dng ic 555:1. Mch a hi n n c bn:

c thphn tch nguyn l ca mch n n mt cch r rng , dhiu,chng ta s dng k t hp hai s hnh.e v hnh.a ,s hnh .e v mch ngdng Ic 555 lm mch n n , s hnh .a k t h p vi s cu trc bn trongIc555.

RV1VARISTOR

VCC

Rb

R11,2K

D2

DIODE

U1

NE555

3

4 8

5

26

7

1

OUT

R S T

V C C

C V

TRGTHR

DSCHG

G N D

0

D1

LED

0

0,01uF

0

RV2VARISTOR

Ra

C2

0


36/56

36

Trong mch ny chn ng ng s 6 v chn x s 7 c ni vo imchung ca mch nh th RT.C Lc ny chn nhn tn hiu t bn ngoi l chn th 2

c im ca mch n n l khi c xung m h p c gi tr ln hn 1/3 vcctc ng vo chn s 2 th mch s thay i tr ng thi v ng ra chn th 3 s cxung d ng ra. r ng xung d ng ng ra khng ph thuc vo r ng caxung kch m ph thuc vo mch nh th RT.C, sau mch s tr li tr ng thi ban u.

Hnh.e

2. Nguyn l m ch n nKhi m i m in t C ni chn 6 v chn 7 xung mass lm opamp (1) c

ng In+ nh hn ng In- nn ng ra V01 = 0V, ng R =0 c mc thp. lc opamp(2) c ng In+ nh hn ng In- nn ng ra V01 = 0V nn ng ra V02 = 0V ,


37/56

37

ng S=0 c mc th p. mach F/F c R=0 v S=0 nh cu trc ca mch chi tit nnF/F c ng ra Q mc cao v qua mch o ng ra chn 3 c mc th p gn 0V.khi ng ra Q o c mc cao to pga6n cc bo ha cho T2 nn lm cho T2 dnni chn 7 ni mass. Chn 6 cng bni mass nn t in C khng th np in,mch s mi tr ng thi ny nu khng c tc ng t bn ngoi

Khing khoa K s c xung m tc ng vo chn trigger s2 lm opamp(2) i tr ng thi, ng S ln mc cao , mc cao ca ng S iu khin lm F/F itr ng thi, ng Q o xung mc th p , ng ra mch o s ln mc cao v chn 3c in p d ng ng ra.lc Q o mc thp nn T2 ng ng dn tC n pin qua Rt .Trong th i gian np in mch vn gi nguyn tr ng thi ny nn ngra mc cao

in p trn t tng theo hm m v khi in p trn t t 2/3 vcc thopamp (1) i tr ng thi,R tng l mc cao R=1 , ng R mc cao s iu khinF/F i tr ng thic ngQ o ln mc cao lm ng ra mch o xung mc th pchm dt xung d ng ng ra.ng thi ,lc T2 c phn cc bo ha nnchn 7 ni mass lm tC x in .Mch s n nh tr ng thi ny nu khng cxung m tc ng vo chn trigger s2.

Th i gian xung d ng ra tc l th i gian np in t 0V ln 2/3 Vcc ctnh nh sau:

in p n p trn t tng theo hm s m l :

Vc =Vcc (1- e T t / ) trong :T =Rt.C

Th i gian tnp c in th t 0V ln 2/3Vcc l t c tnh b i :

Vc =Vcc(1- e T t / ) =2/3Vcc

Suy ra: (1- e T t / )= 2/3 hay l 1-2/3 = eT t /

1/3= e T t / = 1/ e T t / e T t / =3cui cng ta c hm s ng c ca hm s m l ln. nh vy : t =T. ln3 (ln=1,1)

t= 1,1 . Rt.C


38/56

38

3.Dng sng ra t i cc chn :

Bnh th ng chn 2 phi c in p ln hn 1/3Vcc ,khi c xung m th c bin xung phi lm in p chn 2 nh hn 1/3Vcc.

Khi va c xung m chn 2 th ng ra bt u c xung d ng v tC btu np in .

Thi gian xung d ng ra t khng ty thuc vo r ng xung m ng vom ch ty thuc hng s th i gian T ca mch nh th .Nu dng bin tr VR thay cho Rt ta c th thay i r ng xung ra .cch khc l thay i tC bng ccin dung c tr skhc nhau .

4.M ch tr hon dng ki u n n :


39/56

39

Mch tr hon dng kiu n n

Mch n n c ng dng r t r ng ri trong lnh vc t dng iu khinv c bit l mch tr hon .Trong thc t ,ng i ta khng cn to xung iu khincho vo chn s2(Trigger) m mch t to xung khi m in . nh vy khi m im in ng ra cng bt u c xung ra.

Mch in trn l s mch t to xung khi m i m in . trong s chn s 2(trigger) c ni n chn s6(threshold=thm) nn s c chung in pgia mch np Rt.C so vi hai in p chun trong Ic l 1/3 Vcc v 2/3 Vcc.

Khi m in tC bt u n p t 0V ln nn Opamp(2) c ng V In+ ln hnng In- , ng ra V02 mc cao , ng S cng mc cao . Mch F/F c ng Q o mc th p v ng ra ca Ic c Vo =Vcc ,c ngha l tc thi c xung ra . Lc ,Opamp (1) c ng In+ nh hn ng In- nn ng ra V01 mc thp ,ng R cng mc th p

Khi tnp in p n mc 1/3 Vcc th Opamp (2) i trang thi , ng Sxung mc thp nh ng mch F/F vn gi nguyn tr ng thi v xung vn ang cn ng ra .

Khi tnp in p n mc 2/3Vcc th opamp(1) i tr ng thi ng Rle6nmc cao lm mch F/F cng i trang thi , ng Q tng ln mc cao lm ng raca Ic gim xung mc th p Vo = 0V v chm dt xung ng ra .

Thi gian c xung ra , hay r ng , chnh l th i gian tC n p t oV n2/3Vcc v cng c tnh theo cng thc :


40/56

40

t= 1,1Rt.C

trong mch ny chn 7(discharge:x in) h , khng ni vo mch n pRt.C nn tC skhng x in v mch sgimi trang thi ny . Mun c xung

ra ti p th phi tt in r i m li .tr s in tr Rt v C, c gi i hn trong khong :

Rt =10K n 14 K

C= 100pF n 1000pF

V i cc tr s trn Rt v C ,mch n n c th cho ra xung c r ng xungngn nht khong vi us n vi gi .

Nh vy khi m in ,r le RY khng c in do

Vo =Vcc .sau khi chm dt xung ,tc l sau thi gian t th R le Ry c in vVo=0V , khi rle c in s ng hay m cc tip im iu khin mch khc ,th ng l mch cng sut .

Thc ra Ic 555 v h Ic nh th ca n cng dng r t a dng , trongch ng ny ch gi i thiu haing dng c bn nht ca n l mch a hi phi nv a hi n n .

IV. Ic555 giao tip vi cc lo i ti:Ic555 c thgiao ti p v i nhiu loi ti khc nhau v ty tr ng h p mi

loi ti u c mc theo hai cch :

_ti c cp in khi ng ra c in p thp .lc ,Ic snhn dng in titheo chiu t ngun qua ti r i qua Ic . Dng in ti tr ng hp ny c gi l Inhn.

_ti c cp in khi ng ra c in p cao . lc Ic scp dng in cho titheo chiu t ngun qua Ic r i qua ti .Dng in ti trong tr ng hp ny cgi l I ngun .


41/56

41

Kh nng cung cp dng in v in p ca Ic 555 nh sau :

1.Din p ra m c th p :Vi Vcc= 15V .in p Vo chnh l Vce2 khi T2 bo ha .

I L = 10mA => Vo = 0,1V

I L = 50mA => Vo = 0,4V I L = 100mA => Vo = 2V I L = 200mA => Vo = 2,5V

2.Din p ra m c cao :Vi Vcc = 15V. in p Vo = Vcc Vce2 khi t1 bo ha .

I L = 100mA => Vo = 13,3V => Vce2 = 1,7V

I L = 200mA => Vo = 12,5V => Vce2 = 2,5V3.T i l led:


42/56

42

in p ra mc th p in p ra mc cao

Nu ti l led th phi dng din tr ghp ni ti p vi led gi i hn dng qua led .

Ty theo cch mc ti m dng in qua led c cng thc tnh khc nhau.

4.T i l R le:Ic555 c thgiao ti p v i cc loi role iu khin .cc loi role ny c dng th ngnh d i 100mA v in p cng th ng mc thp nh 6V-12V-24V.


43/56


44/56

44

CH NG IV. PHN TCH - THIT K

I. S ngyn l :

II.Nguyn l ho t ng:Khi m i c p ngun cho mch in p xoay chiu qua mch chnh l u s

chuyn thnh dng 1 chiu n nh c tr s l 12 V.

in p 12V ny sphn cc cho in tr 15k v 1k lm cho mch a hi phin hot ng. ng thi in p ny cng sphn cc cho mch a hi n n snsng hot ng khi c xung m kch vo tmch a hi phi n.

Khi c xung m kch vo mch a hi n n tmch a hi phi n th ng ra

ca mch a hi n n s c xung d ng ra , r ng xung d ng ng rakhng ph thuc vo r ng ca xung m m ph thuc vo cc linh kin trongmch (tc l ph thuc vo bin tr 10K v t1uf ) .

Khi c xung d ng ng ra mch a hi n n th n s iu khin lm choBJT dn cho dng in i qua motor lm motor hot ng.

C3C

Q1

Q2SC1815

S2

U1

LM7812/TO

1 3

2

VIN OUT G N D

0

R1

1k

0R2

1kR6

1k

U3

NE555

9

1 0

13

1 1

8

12

7

OUT R S T

DSCHG

C V

T R G

THR

G N D

0

0

D2D1

0

0U2

NE555 3

4

5

62

1

1 4

C V

R S T

OUT

TRGTHR

DSCHG V C C

R4

1k

A - +

MG1

MOTOR SERVO

1 2

Q4Q2SC1815

D3

S1

C2

1n

R3

0

C1

1n

0

C5C

R5

1k

Q2

Q2SC1815

R7

1k

0

Q3Q2SC1815

0

C4C

0

D4


45/56

45

III.Phn tch thi t k :1. Mch ch nh lu

Trong s dtrn ta s dng IC556 v i 2 mc ch l :

- Mch 1 l mch ahi phin to ra xung vung kch kh i chomch 2

- Mch 2 l mch a hi n n v i mc ch l iu chnh r ngxung d ng ng ra thng qua bin tr

Do mch s sng in p DC 12v nn phi c mch chnh l u t in pxoay chiu mt pha sangin p DC12v

M ch ch nh lu

C6

1000uF

D3

1N4007

D2

1N4007

D6

7812

1

2

3

0

0

D1

1N4007

D4

1N4007

0


46/56

46

Trong mch chnh l u trn gm 4 diot ghp li v i nhau thnh 1 cu diot v imc ch l chnh l u dng in xoay chiu thnh dng in 1 chiu nh ng dngdin mt chiu ng ra ca cu diot vn cn nhp nh ch a c phng (hnh 1)

dng in d c phng ta c thmc thm t c tr s l 1000uF vTL7812 to ra din p 12Vdc ng ra.

Nh vy t din p xoay chiu mt pha ng vo ta xl thng quamch chnh l u d thu c din p 1 chiu 12v ng ra

2.Mch a hi phi n s dng ic 556(m ch 1) :

V i nguyn l hot ng c gi i thiu ch ng II ta c dng sng mt s chn nh sau :

0

R31K

U2A

NE556 3

5

1

1 4

62

4

C V

OUT

DSCHG V C C

TRGTHRES

R S T

C11uF

R115K

VCC

C20,01uF

0
http://vi.wikipedia.org/wiki/T%E1%BA%ADp_tin:Gratz.rectifier.en.pnghttp://vi.wikipedia.org/wiki/T%E1%BA%ADp_tin:Gratz.rectifier.en.png


47/56

47

Dng sng chn 5:

Mc ch ca mch trn l kch kh i cho mch da hi phin pha sau khi cin p th p ng ra

3.M ch n n s dng ic 556(m ch 2):

V8

t


48/56

48

Vi nguyn l d c gii thch ch ng II , ta c mt sdng sng ccchn khi c din p th p kch vo chn 8 tmch a hi phi n

VCC

0

0C30,01uF

0

RV110K

U1A

NE556 3

9

13

7

8

12

1 0

C V

OUT

DSCHG

G N D

T R G

THRES

R S T

C41uF

V8

t


49/56

49

4.Cc thng s ca m ch:

Khi m i cp in th tnp theo hm m ng th i v i th i gian tn p lng ra chn 5 c xung d ng . vy thi gian xung d ng tn ti ng ra c tnhtheo cng thc:

T n p =0,69.16.10^-3 =0,01104(s)

Khi tx th in p ng ra c mc th p v th i gian tn ti ca mc th p ng ra l:

T x =0.69.1.10^-3 = 6,9.10^-4(s)

Nh vy chu k xung vung chn 5 l:

T=0,01104+6,9.10^-4 =0,01173 (s)

Khi c xung m kch vo chn 8 th ng ra chn 9 c mc in p cao ,th igian xung d ng tn ti ng ra ph thuc vo bin tr theo cng thc:

T x =1.1.RT.1.10^-6

V9

t


50/56

50

Nh vy khi c xung m kch kh i vo chn 8 th ng ra chn 9 sc mcin p cao qua cu phn thphn cc cho TRANSISTOR dn . Transistor ccng dng nh l mt cng tc iu khin cho ng c .

Nh vy thng qua bin tr RT ta c th iu chnh c in p t vong c v tc ca n hon ton ph thuc vo cch iu chnh bin tr .

Nu chn bin r c gi tr l 10 K th dng sng nh sau:

T x=1,1.10.10^-3=0,011(s)

V8

t

V9

t


51/56


52/56

52


53/56

53


54/56

54


55/56

55

II. Thi cng mch:


56/56

K T LU N: Nh vy trong qu trnh phn tch v thi cng mch nhm nghin cu

phn l n nhng vn ct li ca ti,nh ng do th i gian nghin cu v kinthc cn hn chnn khng trnh khi s thiu st mong qu thy c v cc bnnhit tnh ng gp kin n c hon chnh hn .

Chng ta c thm r ng v pht trin ti thng qua vic iu chnh tc ng c xoay chiu, ng c 3 pha

TI LIU KHAM KHO

-VI MCH V MCH TO SNG-TNG VN ON

-GIO TRNH K THUT XUNG CNB N V NNG CAO

-GIO TRNH I N T CNG SUT

-Cc trang web:

Google.com.vn Alldatasheet.com.vn Ebook.com

Documents

GIỚI THIỆU VỀ MẠCH ĐIỀU CHỈNH TỐC ĐỘ ĐỘNG CƠ