Tesis previa a la obtención del -titulo de Ingeniero Electrónico en la ...

MC1455,MC1555
FIGURE 15 - MQNOSTA8LE WAVEFORMS
IRA - 10 vn. c - 0.01 »F. RL - 1,0 fen ,vcc- is V]
GENERAL OPERATION (continued)
1
1
OutDUt
I
I
1 Trloo«r
FIGURE 17 - ASTABLE CIRCUIT
*Vcc(5 to 15 V)
2
MC1555
MC1*55
6 Threino u¿
-f> 1 1
*~1 1-
1 T T
4=" 4=* •=•
FIGURE 1G-TIMEDELAY FIGURÉIS- ASTABLE WAVEFORMS
\/
1/1 i/
izu x 1/1 i
1/1
i i 1/1 u i/rDnxf
Trixí u M n
100MI 1.0 mi 10 rm IDO CID U) 10 100
Id.TIMEDEUYitl
ln tfic asistí e nvxl* th.e tinw ii connected «o trut It will
tcrrigow itíelf »nd caute the capacitor voltage lo oicillate beuveen
1/3 VCC ind 3/3 Vcc. Seu F'^ure 17.
The e.xternal capacitor chaf oca to 2/3 VQQ through RA and Rg
•nd diichargei to 1/3 VQQ through Rg. 8y varying the ntka of
tr^ev: feíinori ir>e duty cyde cwi be varied. The crwrge «nd
rficwge lifyiM «re independent oí the lUppfy voltaoe.
The ct»fgí tirrw (outpot highl ii given by: t] - O.B95(RA-Ra) C
The diwíhargc time (output lowl by: 12 - 0.695 [Hgl C
Thuithe total peíiod n giv-n by: T - IT i- t2 " Q.69S (RA+2RBÍ C
1 1-14
Tbe frequency of oicillation ii tbcn: f - ~ -
T lRA+2Rg! C
•od frví^ be eawly found « ihown in Figure 19.
TNr Outy cyde ii givvi by: DC
To otxnn the rn»xinxim OUIY cyde RA nxJtt be u tn»ll 11
ponib*e; bol ¡i nxj« «lio be Iwge er>ough lo limit the i
curroit (p-n 7 current) withín ih* ir«xinxjm r«1ng of 1
tr.ni¡UíX (200 rnA).
I7 (A)
RB
(RA -s.i kn.c- o.oi >JF. RL- 1.0 vn;
RB-33kíl.Vcc- 15 V]
FIGURE 19- FREE-HUNNING FREQU^NCY
0.1 1.D ID 100 1JJV ID I 1001
t. FREE-RUNNING FREQUENCY (Hr)