555 time delay
Post on 31-Dec-2015
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555 Time Delay. General Expression for Charging a Capacitor. Substituting. - PowerPoint PPT Presentation
TRANSCRIPT
U1
LM555CN
GND
1
DIS7OUT 3RST4
VCC
8
THR6
CON5TRI2
PrimaryPower12 V
C1uF
OnOff
Key = S
LoadPower12 V
RV1
Key = A 100kOhm
50%
12VRelay
EDR201A12
K
Buzzer
200 Hz
555 Time Delay
0
( ) [ (0) ]t t
C Cf C Cfv t v v v e
RC
General Expression for Charging a Capacitor
12
(0) 0
1
Cf
C
v V
v V
RC RV C
1( ) 12 [0 12]t
RV CCv t e
Substituting
1( ) 12 [0 12]t
RV CCv t e
1
1
1
1
11
1
1
1
1
1
1
( ) 12 12
8 12 12
4 12
1
31
ln3 1
1ln 13
1.09 1 1.1 1
t
RV CC
t
RV C
t
RV C
t
RV C
v t e
e
e
e
t
RV C
t RV C
t RV C RV C
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