1.2. Tiristor (SCR)Nguyn l cu toc tnh, thng sKt cuM tiristorKha tiristorKim tra

1. Nguyn l cu toCu to t bn cht bn dn t lin tip nhau.Nu t in p ngoi vo trong cc tip gip trn c mt tip gip ngcUAK>0 c J2 ngcUAK

Nguyn l lm vic loi iu khin t anoda thm mt cc G (gate) vo n1 Khi c in trng UAK>0, c dng in iAG cp bn dn p1, n1 thnh dy dn, khi A coi nh c t trc tip vo p2, khi xut hin dng iAKKhi c dng iAK, dng iu khin khng cn ngha na. Cc cht bn dn p,n ch tr v trng thi ban u khi ngng dng in

Nguyn l lm vic loi iu khin t Katoda thm mt cc G (gate) vo p2 Khi c in trng UAK>0, c dng in iGK cp bn dn p2, n2 thnh dy dn, khi K coi nh c t trc tip vo n1, khi xut hin dng iAKKhi c dng iAK, dng iu khin khng cn ngha na. Cc cht bn dn p,n ch tr v trng thi ban u khi ngng dng ina)c)+_+

2. c tnh v thng sc tnh c dng nh hnh bn Thng s: C cc thng s nh diod ni trnCc thng s ring ca tiristorITG dng in t gi;tm, tk thi gian m, kha tiristor, tCM = tm + tKUk, ik - in p v dng in iu khindU/dt, di/dt - gii hn tc bin thin in p v dng in

+

So snh tiristor vi cc linh kin bn dn cng sut khcu in chnh ca tiristor l c mt dng in cao, tn hao nh Nhc im: tc chuyn mch chm, tn s lm vic thp

3. Kt cuc im kt cu c bn ca tiristor l dn nhit ra ngoi nhanh nht.Kt cu tiristor c dng nh hnh T3

4. M tiristornh ngha vic m tiristor l chuyn n t trng thi khng dng in sang trng thi c dng in.iu kin c dng in chy qua tiristor Mun c dng in chy qua tiristor phi p ng hai iu kin:C in p UAK>0;C dng in iu khin iGK0

Trong mch in mt chiu, tiristor c m d dng, cn trong mch xoay chiu vic m tiristor phc tp hn do in p v dng in thng xuyn i chiuMt s s m tiristor trong mch xoay chiu

U1U1U1M tiristor bng in p anodM tiristor bng ngun phiu khin bng mch KKKUpa)b)c)U,iU,iU,ittt

5. Kho tiristornh ngha vic kho tiristor l chuyn t trng thi c dng in v trng thi khng dng in (hay pn tr v trng thi ban u)iu kin kho tiristor l phi a dng in chy qua n v 0C th hiu v iu kin ny l t mt in p ngc trc tip trn hai u UAK

Mt s s kho tiristor trong mch mt chiuTrong mch in xoay chiu tiristor t kho do dng in t ng i chiu theo in p, khi dng in bng 0 tiristor t kho.Mt s s kho tiristor trong mch mt chiu

ITINH mch dng inNgn mch tiristorTo dng chy ngc tiristor vi IT +IN=0a)b)c)

Mt s s mch kho tiristor bng mch in ph

f.d.c.

T1T2CLD1ZdUd

Id

T3

CLZdUd

Id

L2

T4

T5C

U1

T1T2U1U1L2T1T3T2IdZdD0Ud

AB+INIT+

6. Kim tra s bBc 1: Kim tra bng ng h vn nng thang in tr o ln nht: A vi K (i u que o) c in tr A vi G (i u que o) c in tr . K vi G (i u que o) c in tr (5 - 20) c nh th ny c th mc tiristor vo mch

Bc 2. Kim tra iu khinDng cc mch a, b mc 4 kim tra tiristor

V d mch kim traTiristor c mc vo li in xoay chiu nh cc hnh v di.iu kin c php mc tiristor vo mch: UN>2. U~Khi kho K h tiristor kho n khng sngKhi kho K ng tiristor dn n sng 1/4 cng sut

7. Diod Shockley (cng h c tnh cn c SUS - SiliconUnilateral Switch)Diod Shockley c cu to bn cht bn dn nh tiristor nhng khng c cng iu khin. Ngi ta ch to linh kin ny c nh c tnh phi tuyn gc phn t th nht nh. Linh kin ny ging diod n p l chng cho dng in chy qua khi in p vt mt ngng no . Khi c dng in chy qua ri, diod shockley c st p bng 0