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Cc mch bo ng n gin

26-11-2011 |fee_08|1 phn hi

yl mch to m thanh n gin dng cho ci bo ng cho cnh st

Mch c to bi 2 con IC 555 dng to dao ng. Tn s c iu khinbi chn 5 ca IC. u tin l IC 1 c lm vic xung quang tn s l 1hz v t47uF c np in v sau lx in lin tc qu trnh c din ra lin tcnh vy. Tn s ra loa c iu ch bi IC2 v ta nghe c m thanh ra loa.Hai bin tr VR1 v VR2 dng iu ch tn s u ra cho Loa. Tn s cng

ln th ting h ci cng to. y l mch bo ng nh sng. c s dngtrong phng ti v khi c nh sng lt vo th mch s pht ra ting bo cho tabit l c nh sng

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7/29/2019 Mach Bao Dong Don Gian

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Nhn vo mch trn kh l n gin v mch ch s dng 1 con 555 to dao

ng pht m thanh ra loa v 1 con LDR cm bin nh sng.+ 555 y l con to dao ng xung vung trong mch ny n to dao ng l1Khz cp cho ti l Loa+ LDR l cm bin nh sng. Khi khng c anh sng th cm bin ny c gi trin tr l v cng cn khi c nh sng mch th cm bin c gi tr in trl 0.Khi c nh sng th LDR s c in tr bng 0 khi n s phn cc thun chocon BC158 dn n cp in p vo chn 4 ca 555 l mch dao ng 555 hotng v pht m thanh ra loa. Cn khi khng c nh sng th LDR c gi tr intr v cng do n ko phn cc c cho BC158 ==> Khng c tn hiu raloa. Bin tr 100K dng iu chnh mc cng nh sng cnh bo. y lmch bo trm nh 4 trong 1. S dng NE556 lm cnh bo kt hp vi chungbo ng,

7/29/2019 Mach Bao Dong Don Gian

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Mch ny c hot ng khi phi tha mn 4 iu kin khc sau y:+ Khi n sng th cm bin LDR1 c bt+ Khi n sng th cm bin LDR2 c bt+ Khi m ca+ Khi chm vo vt (Hnh v)Nu m k trm b gp phi 1 trong 4 trng hp trn th s c 1 ting chungbo ng cho ngi bit l c k trmy l mch khng ch cho chng ta bit

mc nc thi im hin ti m n cn cnh bo cho chng ta khi mc nc y bng hin th ln cc n LED v chung bo ng

7/29/2019 Mach Bao Dong Don Gian

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Mch s dng IC CMOS CD4066 ng ct v a tn hiu mc nc ra ccLED (Trn hnh v). Khi mc nc trong thng khng c nc th in tr 180Km c ni vi mc thp (GND) nn khng c n LED no sng. Khi c mcnc vo th u tin n kt ni gia S1 vi ngun dng thng qua cc iontrong nc khi ng kha S1 to cho n LED 1 sng. C nh vy th ccmc 2, 3, ,4 cng nh vy mc nc n u th n s sng n .Ring khi mc nc y c thm 1 chung cnh bo l nc trong thng y. bo hiu cho con ngi l nc y thng.

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y l mch cnh bo mc nc y hay bo ng cho 1 mc nc no .Mch s dng con 555 to dao ng pht m thanh ra loa. Tn s ra loa bong s l tn s dao ng ca IC555 : Tn s l : f = 1/(0.693*0.022.10^-6*(100.10^3+9.4.10^3) = ?. Tn s ny khng c ln hn 20Khz v nh thlm sao m tai ngi c th nghe thy c. Hot ng : Mch kh l n gin gm 1 con BC109C v b cm bin cng khn gin l cm bin nc. Khi mc nc dng cao n ch cm bin nc th

lc dng in t ngun c dn qua ion nc phn cc cho B caTransitor. Khi transitor dn dng t ngun cp ngun cho 555. Dn n 555to dao ng pht m thanh ra loa. Khi mc nc khng chm cm bin th Bkhng c phn cc ngt ngun cp cho 555 nn loa s khng pht tn hiu.