GIO N L THUYT S: 01 Thi gian thc hin: 03Tit Thc hin: ngy thng nm 2010 VT LIU IN BI: - KHI NIM V VT LIU IN - PHN LOI VT LIU INMC TIU HC TP:

Sau khi hc xong bi hc ny hc sinh c kh nng: - Hiu c th no l vt liu in. - Cu to nguyn t v phn t ca vt liu in. - Phn loi c vt liu in. DNG V PHNG TIN DY HC:

Gio n, cng bi ging. Bng, phn v ti liu tham kho. Thi gian: 01 pht S hc sinh vng..Tn......................................... .........N NH LP III. THC HIN BI HC: PHNG PHP TT NI DUNG GING DY

Hot ng ca gio vin

Hot ng ca hc sinh

TG

I

Khi nim v vt liu in. Khi nim.Vt liu in l tt c nhng cht liu dng sn sut cc thit b s dng trong lnh vc ngnh in. Thng c phn ra cc vt liu theo c im, tnh cht v cng dng ca n, thng l cc vt liu dn in, vt liu cch in, vt liu bn dn v vt liu dn t.

t vn vo bi Thuyt trnh

Lng nghe, suy ngh, ghi chp

Cu to nguyn t ca vt liu.Nguyn t l phn t c bn nht ca vt cht. Mi vt cht u c cu to t nguyn t v phn t theo m hnh nguyn t ca Bo. Nguyn t c cu to bi ht nhn mang in tch dng (gm proton p v ntron n) v cc in t mang in tch m (electron, k hiu l e) chuyn ng xung quanh ht nhn theo mt qu o xc nh. Nguyn t : L phn nh nht ca mt phn t c th tham gia phn ng ho hc, nguyn t gm c ht nhn v lp v in t V - Ht nhn : gm c cc ht Proton v Nrton nguyn t - V ht nhn gm cc electron chuyn ng xung quanh ht nhn theo qu o xc nh. Ty theo mc nng lng m cc in t c xp thnh lp. H t nhn iu kin bnh thng, nguyn t trung ha v in, Hnh 1.1. Cu tc l: nguyn t

to

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(+)ht nhn (-)e = Khi lng ca e rt nh: me= 9,1 .10-31 (Kg)

Cu to phn tL phn nh nht ca mt cht trng thi t do n mang y cc c im, tnh cht ca cht , trong phn t cc nguyn t lin kt vi nhau bi lin kt ha hc.Vt cht c cu to t nguyn, phn t hoc ion theo cc dng lin kt di y: a. Lin kt ng ha trLin kt ny c trng bi s kin l mt s in t tr thnh chung cho cc nguyn t tham gia hnh thnh phn t. Ly cu trc ca phn t clo lm v d: phn t ny gm 2 nguyn t clo v nh bit, nguyn t clo c 17 in t, trong 7 in t lp ngoi cng (in t ho tr). Hai nguyn t clo lin kt bn vng vi nhau bng cch s dng chung hai in t nh trn hnh 1.3 . Lp v ngoi cng ca mi nguyn t c b sung thm mt in t ca nguyn t kia.

II

Thuyt trnh

Lng nghe, suy ngh, ghi chp

Cl + Cl Cl Cl

Phn t lin kt ng ho tr c th l trung tnh hoc cc tnh. Phn t clo thuc loi trung tnh v cc trung tm in tch dng v in tch dng trng nhau. Axit clohydric HCl l v d ca phn t cc tnh. Cc trung tm in tch dng v m cch nhau mt khong v nh vy phn t ny c xem nh mt lng cc in. Ty theo cu trc cc phn t i xng hay khng i xng m chia cc phn t ra lm hai loi - Phn t khng phn cc l phn t m trng tm in tch m trng vi trng tm in tch dng - Phn t phn cc l phn t m tm in tch m cch trng tm in tch dng mt khong l c trng cho s phn cc ngui ta dng m men lng cc Pe = q.l Trong : q: l in tch l: c chiu q n +q v c ln bng l( khong cch gia trng tm in tch dng v trng tm in tch m)

b. Lin kt IonLin kt ion c xc lp bi lc ht gia cc Ion (+) v Ion(-). Lin kt ny ch xy ra gia cc nguyn t ca cc nguyn t ha hc tnh cht khc nhau. c trng cho dng lin kt kim loi l lin kt gia cc

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kim loi v phi kim to thnh mui, c th l Halogen v kim loi kim gi l mui Halogen ca kim loi kim. Lin kt ny kh bn vng. Do vy nhit nng chy ca cc cht c lin kt Ion rt cao V d: lin kt gia Na v Cl trong mui NaCl l lin kt ion ( v Na co 1 electron lp ngoi cng cho nn d nhng 1 electron to thnh Na+, Cl c 7 electron lp ngoi cng cho nn d nhn 1 electron to thnh Cl- , hai ion ny tri du s ht nhau v to thnh phn t NaCl, mui NaCl c tnh ht m tnc =8000C, tsi 1 v khng ph thuc vo cng t trng ngoi. Loi ny gm c oxy, nit, oxyt, mui st, mui cban, mui niken, kim loi kim, nhm, bch kim. - Cht nghch t: l cht c t thm < 1 v khng ph thuc vo cng t trng ngoi. Loi ny gm c hydro, cc kh him, a s cc hp cht hu c, ng, km, bc, vng, thu ngn, antimon, gali,... . Cc cht thun t v ngch t ging nhau ch t yu, tc l cng c t thm sp s bng 1. V d nhm l cht thun t c = 1,000023, cn ng l cht nghch t c = 0,999995. - Cht dn t: l cht c t thm >> 1 v ph thuc vo cng t trng ngoi. Loi ny gm c st, niken, cban v cc hp kim ca chng, hp kim crm - mangan, galonit v ferit c cc thnh phn khc nhau. 3. ng cong t ha Tnh t d th hin ch khi ct b t trng ngoi (cho H = 0, khi ct b dng in t ho trong cc cun dy) th cht st t vn cn gi t tnh (duy tr mt t trng c t cm B). Tnh cht t d c kho st trong qu trnh t ho vt liu st t bng cch thay i chiu v cng t trng H tc ng ln mi trng st t. Hnh v

Thuyt trnh, trc quan hnh v

Lng nghe, suy ngh , ghi chp

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II III

Cng c kin thc v kt thc bi. Thc hnh .a ra cu hi Vit bi thu hoch

IV Hng dn t hc Ngun ti liu tham kho

Gio trnh Vt liu in - nh xut bn gio dc

KHOA IN - IN T

Ngy thng nm 2011 Ch k ca gio vin

Cao Th Thun

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GIO N L THUYT S: 07 Thi gian thc hin: 05 tit Thc hin: ngy thng nm 2011BI: MC TIU HC TP: - MCH T , TNH TON MCH T. - MT S VT LIU DN T THNG DNG

Sau khi hc xong bi ny hc sinh s c kh nng: - Nm c cc cng thc c bn,s thay th ca mch t, mch t xoay chiu. - Mt s vt liu dn t thng dng DNG V PHNG TIN DY HC:

Gio n, cng bi ging. Bng, phn v ti liu tham kho. Thi gian: 01 pht S hc sinh vng..Tn......................................... ........N NH LP III. THC HIN BI HC: PHNG PHP TT NI DUNG GING DYCc cng thc c bn 1. Khi nim Cac thit bi in nh rle, cng tc t, khi ng t, ap t mat,...u co b phn lam nhim vu bin i t in nng ra c nng. b phn nay gm co cun dy va mach t goi chung la c cu in t, chia lam hai loai xoay chiu va mt chiu. nm c nhng quy lut in t ta xet mach t va phng phap tinh toan mach t.

Hot ng ca gio vin

Hot ng TG ca hc sinh

I

Nu vn , ging gii

Lng nghe, suy ngh, ghi chp

Mach t c chia lam cac phn: - Thn mach t. - Np mach t. - Khe h khng kh phu p v khe h khng khi chinh c - Khi cho dong in chay vao cun dy thi i qua, t thng nay cung chia lam ba phn trong cun dy co t thng :

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a) T thng chinh l thnh phn qua khe h khng khi goi la t thng lam vic lv b) T thng tn t gi la thanh phn i ra ngoai khng khi xung quanh c) T thng ro l thnh phn khng i qua khe h khng khi chinh ma khep kin trong khng gian gia loi va thn mach t.

2.Tinh toan mach tTinh toan mach t thc cht la giai hai bai toan: - Bi ton thun: Bit t thng tinh sc t ng F = IW loai nay gp khi thit k mt c cu in t mi. - Bai toan nghich : bit sc t ng F = IW tnh t thng (gp khi kim nghim cac c cu in t co sn). giai quyt c hai bai toan trn cn phai da vao cac c s li thuyt sau: - Bit ng cong t hoa cua vt liu st t. - Nm vng cac inh lut c ban v mach t. - Bit c t dn khe h.

Thuyt trnh

Lng nghe, suy ngh, ghi chp

- S thay th ca mch t v tnh t dn khe he khng kh ca mch t3. Mch t xoay chiu Mach t xoay chiu khac mach t mt chiu vi nhng c im sau: a) Trong mach t xoay chiu: i=i(t) nn i = Im Sin t dong bin thin co hin tng t tr, dong xoay, dong in chay trong cun dy phu thuc vao in khang cua cun dy, ma in khang phu thuc t dn mach t nn t tr toan mach t cang ln (khe h khng khi cang ln) thi in khang cang be va dong in trong cun dy cang ln. Khi np mach t m dong in khoang I = (4 15)Im Chu y: khi ong in c cu in t, phai kim tra np xem ong cha, nu np m co th lam cun dy bi chay. b) Lc hut in t F bin thin F=F(t) co thi im F=0 co thi im F=Fmax dn n mach t khi lam vic bi rung, han ch rung ngi ta t vong ngn mach. T thng bin thin lam xut hin sc in ng trong vong ngn mach, trong vong co dong in mc vong khep kin, lam vong ngn mach nong ln. Goi Wnm la s vong ngn mach (thng Wnm=1). Theo inh lut toan dong in co: IW+ InmWnm = c) Trong mach t xoay chiu co tn hao dong xoay t tr lam nong mach t, co th xem nh tn hao trong vong ngn mach. Nu goi Pxt la cng sut hao tn do dong xoay va t tr thi co th biu din di dang tng ng nh mt vong ngn mach. 2 Pxt = I nm .rnm d) T dn ro quy i Khac vi mach mt chiu vi: Sc t ng tng F = IW sc t ng oan X la x FX = I .W l x W X = W t thng mc vong oan x la yrx =Wx.frx l ql Cui cng c Gr = la t dn ro trong mach xoay chiu. 3 V phng phap tinh toan mach t xoay chiu cung ging

Thuyt trnh

Lng nghe, suy ngh, ghi chp

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mach t mt chiu nhng phai lu y bn c im trn. Vi du mach t xoay chiu nh hinh minh ha:

Thuyt trnh, Lng nghe, trc quan suy ngh, ghi hnh v, m chp thoi

Khi ve mach t ng tri phai xet n tac dung cua vong ngn mach, tn hao dong xoay va t tr. - Khi np ong, bo qua t thng ro nhng phai k n t tr va t khang mach t nn dang nh hinh minh ha a. - Khi np mach t m, co th bo qua t tr va t khang cua mach t, nhng phai xet n t thng ro cho nn mach t ng tri co dang nh hinh minh ha b.

Hnh v4. CC VT LIU ST T a. Vt liu t mm Vt liu t mm c s dng lm mch t ca cc thit b v dng c in c t trng khng i hoc bin i. Vt liu t mm l t trng kh t HK nh (di 400 A/m), t thm ln v tn hao t tr nh. Vt liu st t mm gm c thp k thut, thp t ccbon, thp l k thut in, hp kim st - niken (pecmaloi) v ferit. -. Thp k thut (gm c gang) c dng lm t trng trong mch t khng i. Thp k thut c cng

Thuyt trnh

Lng nghe, suy ngh, ghi chp

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t cm bo ho cao (ti 2,2 Tesla), hng s t thm ln v cng kh t nh. - Thp l k thut in l hp cht st-silic (1-4%Si). Silic ci thin c tnh t ca st k thut: tng hng s t thm, gim cng kh t, tng in tr sut ( gim dng in Fuc hay dng in xoy). - Pecmaloi l hp kim st - niken (22%Ni), ngoi ra cn c mt s tp cht: Molipden, crm, silic, nhm. Pecmaloi c hng s t thm ln gp 10-50 ln so vi thp l k thut in, ch cn mt cng t trng nh vi phn n vi chc phn trm A/m, thp t ti cng t cm bo ho. - Ferit l vt liu st t gm c bt oxt st, km v mt s nguyn t khc. Khi ch to, hn hp c p trong khun vi cng sut ln v nung n nhit khong 12000C, thnh phm s c dng theo mun. Ferit c in tr sut rt ln, thc t c th coi gn nh khng dn in, nn dng in xoy chy trong ferit rt nh. Bi vy cho php dng ferit lm mch t ca t trng bin thin vi tn s cao. Ferit nikenkm bng cch nhit phn mui, gi l Oxyfe. Ferit v Oxyfe c hng s t thm ban u ln, t d nh (0,18-0,32 Tesla) v t trng kh t nh (8-80 A/m). Chng c s dng rt rng ri lm mch t ca cc linh kin in t, khuch i t, my tnh,.... b. Vt liu t cng Vt liu t cng c dng ch to nam chm vnh cu. c im ca loi ny l c t d ln. Thnh phn, t d v trng kh t ca mt s vt liu t cng cho bng .

Thuyt trnh

Lng nghe, suy ngh, ghi chp

III Thc hnh. - H thng li kin thc bi hc IV Cng c kin thc v kt thc bi. - Ghi cu hi v nh n tp V Hng dn t hc Ngun ti liu tham kho:Gio trnh vt liu in - Nh sut bn gio dcKHOA IN - IN T

Ngy thng nm 2011 Ch k ca gio vin

Cao Th Thun Gio n l thuyt s : - 44 -

Thi gian thc hin: 01Tit Thc hin: ngy 19 thng 01nm 2011 CHNG 4: KH C IN IU KHIN BI 4.1: CNG TC TMC TIU HC TP:

Sau khi hc xong bi ny hc sinh s c nng lc: -Nm c khi nin v cu to, phn loi ca cng tc t v trnh by c nguyn l lm vic ca cng tc t xoay chiu 3 pha kiu in t. - ng dng c cng tc t vo thc t lm c s cho phn thc tp tay ngh sau ny. -Pht huy tnh tch cc t duy, m bo an ton trong qu trnh hc tp. DNG V PHNG TIN DY HC:

Gio n, cng bi ging. Bng, phn v ti liu tham kho, my chiu. Thi gian: 1 S hc sinh vng..Tn........................................ .......N NH LP III. THC HIN BI HC: PHNG PHP TT NI DUNG GING DY TG

Hot ng ca gio vin

Hot ng ca hc sinh 2 Lng nghe, suy ngh, tr li cu hi

Bi trc chng ta i tm hiu Dn nhp v kh c din ng ct, mt trong Nhc li kin s kh c in ng ct l cu thc bi hc dao.Cu dao l mt kh c in c c nu cu hi gi mt cu to kh n gin, n c hc sinh nhc dng ng ct mch in trc li kin thc tip bng tay, mch in ng ct bi hc c. bng cu dao l mch in khng Em hy trnh ti hoc ti nh.Vy nu nhng bi tc dng ca cu dao? mch in c dng ti ln yu cu ng ct t xa hoc gin tip hay Nhn xt cu t ng, th cn phi lm nh th tr li ca hc sinh. no? Th trn thc t c mt loi kh c in dng ng ct va nh nhng li an ton v c th p ng c nhng yu cu trn vy kh c in l g? Ti - 45 -

sao n li c tnh u vit nh vy? th chnh l cng tc t. 4.1.1

Khi nim v phn loi cng tc t. a. Khi nim.Cng tc t l kh c in dng ng, ct thng xuyn cc mch in ng lc, t xa, bng tay hay t ng. Nu bng tay thng qua b (nt n). Nu t ng c kt ni thng qua(Rle thi gian, cng tc hnh trnh). Cng tc t c th dng cho mch in ng lc c in p n 500V, dng in nh mc n 800A, v tn s ng ct ln n 1500 ln trong 1h. b. Phn loi. phn loi cng tc t c nhiu cn c: - Theo in p iu khin t vo cun ht ca cng tc t: cng tc t 1 chiu, cng tc t xoay chiu. - Theo s cc: 1cc, 2cc, 3 cc (loi 1 cc, 2 cc thng dng ng ct cho mch mt chiu hoc xoay chiu 1 pha, cn loi 3 cc dng ng ct cho mch xoay chiu 3 pha, v vy cng tc t 3 cc cn gi l cng tc t xoay chiu 3 pha). - Theo cng dng: cng tc t n, cng tc t kp( cng tc t kp - 46 Thuyt trnh Lng nghe, suy ngh , ghi chp Thuyt trnh Lng nghe, suy ngh , ghi chp

4

4.1.2

gm 2 cng tc t n lin kt c kh vi nhau). Ngoi ra cng tc t cn c phn loi theo nguyn l tc ng c loi kiu in t, c loi kiu thy lc hay kh nn, mi loi c s dng theo nhng lnh vc khc nhau ty mch yu cu, nhng trong thc t hay s dng nht l loi cng tc t xoay chiu 3 pha kiu in t.

4.1.3

Cu to. (Hnh v). Cu to cng tc t kiu in t. - Li thp tnh (1), li thp ng (2). - Cun ht K. - Gi tip im ng s(3). - Tip im chnh K1, tip im ph thng m K2, tip im ph thng ng K3. - Vng ngn mch (4). Ging - L so hi v (5). gii,trc quan Nguyn l hot ng. hnh v myCng tc t xoay chiu 3 pha hot ng da trn nguyn tc Nam chm in. - Khi cun ht (K) cha c cp in th l so (5) y phn ng gm li thp ng - 47 -

Trc quan hnh v my chiu, din gii, m thoi, pht vn. Nu cu hi hc sinh cng c li kin thc GV va ging. mi mt em hc sinh k tn cc b phn chnh ca cng tc t?. Nhn xt cu tr li ca hc sinh

Lng nghe quan st, suy 11 ngh , ghichp, tr li cu hi

chiu, m thoi, pht vn. nu cu hi: -Quan st trn hnh v khi cun (K) cha c in th cc

Lng nghe, quan st, t 12 duy, tr li cu hi, ghi chp.

4.1.4

s (2) v gi tip im ng s (3) i ln lc ny tip im (K1), (K2) trng thi m, tip im (K3) trng thi ng. - Khi cun ht (K) c cp in( dng in xoay chiu) th li thp(1) ht li thp(2) ko theo gi tip im (3) xung, ng tip im chnh (K1),(K2) v m tip im (K3). *Ch : Khi lc ht ca hai li thp thng sc cng ca l so (5) th lc li thp(2) mi b ht li thp(1) cc tip im ca cng tc t mi chuyn trng thi

tip im K1,K2,K3 ntn? - khi ichiu dngintrong cun ht (K) th 2 li thp s htnhauhay y nhau? - Khi cun ht(K) b mt in th s nh th no? Nhn xt cu tr li

ng dng:- iu khin ng c xoay chiu 3 pha.

11 Trc quan hnh v trn my chiu v mt mch in ng dng Quan st, t ca cng tc duy, tr li cu hi t dng iu khin ng c xoay chiu 3 pha 3 1

II

Cng c kin thc v kt thc bi.

IV Hng dn t hc Ngun ti liu tham kho

KHOA IN - IN T

Ngy thng nm 2011 Ch k ca gio vin

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Cao Th Thun

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