Upload
dhonu
View
277
Download
6
Embed Size (px)
Citation preview
555 TIMER
THE MOST VERSATILE IC
USED IN ELECTRONICS
CIRCUITSELECTROKRITI V6.0INNOVATE TO IMPLEMENT…TEAM EHC
WHAT IS 555 TIMER
IT IS A 8 PIN IC.
GENERALLY USED TO GENERATE
CLOCK
PULSE OF WIDE RANGE OF
FREQUENCY
CAN BE ALSO USED TO
GENERATE SPECIFIC TIME DELAYTEAM EHC
INSIDE 555 TIMER
-
+-
+
RESET
SET
Q
Q
COMP1
COMP2
Flip-Flop
3 RESISTORS OF 5K
2 COMPARATORS
S-R FLIP FLOP
TRANSISTOR
TEAM EHC
COMPARATOR
-
+
V1
V2
VOUT
IF V1>V2 THEN VOUT = -
VSAT
IF V1<V2 THEN VOUT =
+VSAT
+VSA
T
-VSAT
-
+-
+
RESET
SET
Q
Q
COMP1
COMP2
Flip-Flop
TEAM EHC
3 RESISTORS VCC
0.66 VCC
0.33 VCC
USED AS VOLTAGE DIVIDER NETWORK
GIVES THE REFERENCE VOLTAGE TO THE COMPARATORS
-
+-
+
RESET
SET
Q
Q
COMP1
COMP2
Flip-Flop
TEAM EHC
S-R FLIP FLOP
RESET
SET Q
Flip-Flop
Q
S R Q Q’0 0 HOL
D
1 0 1 0
0 1 0 1
-
+-
+
RESET
SET
Q
Q
COMP1
COMP2
Flip-Flop
TEAM EHC
TRANSISTORA
B
VI
N
C
E
VI
N
USED AS A SWITCH
IF VIN=1 THEN C-E IS SHORTED
IF VIN=0 THEN C-E IS OPEN
CKT
-
+-
+
RESET
SET
Q
Q
COMP1
COMP2
Flip-Flop
TEAM EHC
PIN CONFIGURATION
Control Voltage (5)
Threshold Voltage (6)
Trigger Voltage (2)
Ground (1)
Vcc (8) Discharge (7)
Reset (4)
Output (3)
-
+
-
+
RESET
SET
Q
Q
COMP1
COMP2
Flip-Flop
TEAM EHC
MODE OF OPERATION
MONOSTABLE MODE
ASTABLE MODE
TEAM EHC
ASTABLE MODE
TEAM EHC
8
5
6
2
1 4
3
7
ASTABLE MODE CALCULATION
TIME PERIOD TON=0.693(RA+RB)C TOFF=0.693RBC TTOT=0.693(RA+2RB)C
CAN YOU CALCULATE THE FREQUENCY AND DUTY CYCLE OF THE ASTABLE MODE ?
TEAM EHC
MONOSTABLE CALCULATION
T = 1.1RC
TEAM EHC
MONOSTABLE MODE
TEAM EHC
8
5
6
2
1 4
3
7
LETS MAKE IT
TEAM EHC