Question

Q4(b) Two 555 timers are connected together as shown in Figure Q4(b). (i) Draw and completely label the waveforms for 101, VC1, VO and VC3. All the waveforms must be drawn parallel at the time-axis and clearly show the relationship between them. (ii) Calculate the duty cycle of the output waveform VO. - +15V R: 75k2 42k2 OVO Rs 30222 OF 330F 0.01F |

Answer 1

Selution Grirau CRe: YERI Vol Vo 30K E32 555 2 555 0-6/MF uf Stagez Stagel Shgel • Pon 2 ond 6 elorted • Astale Mutiidrator Confignalion Capacitn G-- chago thomugh (BtB) Disclago hiough y

For the time Capalita Changes > When Cepacilos Vottage v, reaches Vh= fvcc=or op becones Tow Now Chpalitor - For the time Capacitor dicharge, /p vor Hmaing low. Cwhen the Capacelor vollage vg belomes bess ham - py g helgh stast dschanging toward ov olp once again be lanes heigh Now the Capacir Steat cheiging towands Vec. - The cycde repeat bnd sectongular lakine form i Gbt ained at V01.

0-69 [BstB]G o69 [105 kJ 47nF Tg= Charging time for 9 = 34/ms o-69 R3G = 0-973 mS -Th= Dischangeig trine for 1 = Stage 2: op voj š used as trigger em pin @ - Monestiable Malti vibrater lonfignatiom Tome of CepRits 9 Teme Tg-> Changing T3= Pulse width= IR,C3 = 11x 42X103X 3INF :1:525ms GAanorer the Vy ahicl is adeo triggr for stage@ goes belus % vcc -6 belomes high G stast clargig hrough H tarads VICESV 16 rCC CWhen Voctage a Goss Cg (VG) belomes > Viy= 10V

> dutqut _Yo belores low Cnd Cepalitor lischarges Commedictely through pin . k pube ware forme is gorer ated at Vec= ISV Tel - jov ळ। =ISV

rom the abore graph wie Conlliude that For olp vo T= "Time peri od of Vo) Td, + Te 0-973 ms+ 3-4H ms 4.383 ms Adso Tg= Palse width = ON Time ToN= li 525ms Tons lo525 = 0•348 4-383 > Duty Cycle of Vo - 34. 8 %- Dity Cyde= 34-8 %