The document discusses the IC 555 timer integrated circuit. It describes how the IC 555 has been widely used since 1971, with over 1 billion units sold. It can be used in various operating modes like monostable, astable, and bistable. The document provides examples of using the IC 555 in monostable and astable modes for applications like turning on an LED periodically or building a clap-activated robot. Formulas for calculating timing are also given.

1. IC 555
ThinkLABS
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2. IC 555 : “The IC Time Machine”
 Multipurpose timer IC
 Designed and built in 1971
 Still widely used, with over
1billion units sold
worldwide
 Cheap, Stable, Easy to use
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3. IC 555: Applications
 Operating modes
 Monostable
 Astable
 Bistable
 Non-traditional applications
 Buffer
 NOT Gate
 Comparator
 Schmitt Trigger
 many more…
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4. IC 555: Monostable Mode
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5. IC 555: Monostable Mode
 One shot multivibrator
 Formula:
 T = 1.1 x R1 x C1
Example:
R1 = 10K
C1 = 100uF
T = 1.1 seconds
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6. IC 555 Monostable
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7. IC 555 Monostable + Clap
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8. IC 555: Clap activated Robot
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9. IC 555: Turn when clapped
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10. ACTIVITY
 Use the 555 Timer IC to periodically ON - OFF the LED.
Without Touching the Circuit!!
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11. IC 555: Astable Multivibrator
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12. IC 555: Astable Multivibrator
f = 1/(.693 x C1 x (R1 + 2 x R2))
Example:
R1 = 10K
R2 = 10k
C1 = 100uF
F = ~ 0.48 Hz
T= ~ 2 sec
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13. IC 555: Astable Multivibrator
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14. BACK TO SENSORS
Proximity Sensing
 Can we use the line sensors to detect objects??
 How do we remove the Ambient Light??
 Mechanical Filter
 Electronic Filter
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15. Modulated Sensor
Obstacle
IR RX
IR
Transmitter Receiver
Signal Generator Signal
Filtering
(LM555 oscillator) Conditioning
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16. Sensors (TSOP 1738)
 Used as remote control
receivers in TV, Music
players, etc..
 Available for 30Khz to
56Khz carriers
 Immune to ambient light
 Output is active low and
toggles between 0 to 5V
 Easy to use
 Very Sensitive
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17. Modulating using IC 555
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18. Modulated Sensor
IR LED I/P
TSOP O/P
GND
Vcc
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19. OBSTACLE AVOIDER
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