The document describes the 555 timer integrated circuit. It consists of two voltage comparators, a bistable flip-flop, a discharge transistor, and a resistor divider network. It can be configured as an astable multivibrator to generate a continuous train of pulses or as a monostable multivibrator to generate a single pulse in response to a trigger. The 555 timer is used in a variety of applications including timing, pulse generation, and pulse width modulation. Key parameters like frequency and duty cycle depend on external resistor and capacitor values.
This ppt provides a brief overview on thyristors commonly known as SCRs. V- I characteristics curve, triggering methods, protection methods, series and parallel operations of SCRs, applications are discussed in this slide.
This ppt provides a brief overview on thyristors commonly known as SCRs. V- I characteristics curve, triggering methods, protection methods, series and parallel operations of SCRs, applications are discussed in this slide.
The full basics of Electrical Components can be seen in the link http://bit.ly/2PIOIQM
A switch in an electronic device is used to interrupt the flow of electricity or electric current. Electrical switches are binary devices, they can be either completely off or completely on. In simple English, a switch is an electronic device that is used to break or make the electronic circuit.
1.Introduction
The 555 IC was designed in 1971 by Hans Camenzind under contract to SigNetics Corporation.
555 timer is a highly stable circuit used to generate time delays, or Oscillations.
A single 555 timer can provide time delay ranging from microseconds to hours.
It operates from a wide range of power supplies ranging from + 5 Volts to + 18 Volts supply voltage.
2.Pin Configuration
3.Working of Pin
4.555 Integral circuit
5.Operating modes of IC
6. Bistable Mode
In bistable (also called Schmitt trigger) mode, the 555 timer acts as a basic flip-flop.
The trigger and reset inputs (pins 2 and 4 respectively on a 555) are held high via pull-up resistors while the threshold input (pin 6) is simply floating.
Thus configured, pulling the trigger momentarily to ground acts as a 'set' and transitions the output pin (pin 3) to Vcc (high state).
Pulling the reset input to ground acts as a 'reset' and transitions the output pin to ground (low state). No timing capacitors
Pin 5 (control voltage) is connected to ground via a small-value capacitor (usually 0.01 to 0.1 μF). Pin 7 (discharge) is left floating
7.Monostable Mode
Pulse generator circuit which the period is calculated from RC network and connected to external of 555 timer
Stable when the output logic LOW (logic = 0)
When a pulse is trigger at pin 2 (normally negative trigger pulse), timer output will change to HIGH (+Vs) for a while and change to LOW (stable condition). The condition will continue LOW until pulse is trigger again.
The timing period is triggered (started) when trigger input (555 pin 2) is less than 1/3 Vs, this makes the output high (+Vs) and the capacitor C1 starts to charge through resistor R1. Once the time period has started further trigger pulses are ignored.
The threshold input (555 pin 6) monitors the voltage across C1 and when this reaches 2/3 Vs the time period over and the output becomes LOW,
At the same time discharge (555 pin 7) is connected to 0V, discharging the capacitor ready for the next trigger.
8.Astable Mode
Astable multivibrators are also known as Free-running Multivibrator.
Astable do not need trigger pulse for external to change the output.
The period for LOW and HIGH can be calculated based on resistor and capacitor value that connected at outside of timer.
9.Applications
Schmitt trigger
PPM
PWM
Linear Ramp generator
Precision Timing
Pulse Generation
Time Delay Generation
Sequential Timing
Used as a quad timer
10. Conclusion
Hence 555 IC timer can produce very accurate and stable time delays, from microseconds to hours. It can be used with supply voltage varying from 5 to 18 V. Timer can be used in monostable mode of operation or astable mode of operation. Its various applications include waveform generator, missing pulse detector, frequency divider, pulse width modulator, burglar alarm, FSK generator, ramp generator, pulse position modulator etc.
The complete list of thyristor family members include diac (bidirectional diode thyristor), triac (bidirectional triode thyristor), SCR (silicon controlled rectifier), Shockley diode, SCS (silicon controlled switch), SBS (silicon bilateral switch), SUS (silicon unilateral switch) also known as complementary SCR or CSCR, LASCR (light activated SCR), LAS (light activated switch) and LASCS (light activated SCS).
The full basics of Electrical Components can be seen in the link http://bit.ly/2PIOIQM
A switch in an electronic device is used to interrupt the flow of electricity or electric current. Electrical switches are binary devices, they can be either completely off or completely on. In simple English, a switch is an electronic device that is used to break or make the electronic circuit.
1.Introduction
The 555 IC was designed in 1971 by Hans Camenzind under contract to SigNetics Corporation.
555 timer is a highly stable circuit used to generate time delays, or Oscillations.
A single 555 timer can provide time delay ranging from microseconds to hours.
It operates from a wide range of power supplies ranging from + 5 Volts to + 18 Volts supply voltage.
2.Pin Configuration
3.Working of Pin
4.555 Integral circuit
5.Operating modes of IC
6. Bistable Mode
In bistable (also called Schmitt trigger) mode, the 555 timer acts as a basic flip-flop.
The trigger and reset inputs (pins 2 and 4 respectively on a 555) are held high via pull-up resistors while the threshold input (pin 6) is simply floating.
Thus configured, pulling the trigger momentarily to ground acts as a 'set' and transitions the output pin (pin 3) to Vcc (high state).
Pulling the reset input to ground acts as a 'reset' and transitions the output pin to ground (low state). No timing capacitors
Pin 5 (control voltage) is connected to ground via a small-value capacitor (usually 0.01 to 0.1 μF). Pin 7 (discharge) is left floating
7.Monostable Mode
Pulse generator circuit which the period is calculated from RC network and connected to external of 555 timer
Stable when the output logic LOW (logic = 0)
When a pulse is trigger at pin 2 (normally negative trigger pulse), timer output will change to HIGH (+Vs) for a while and change to LOW (stable condition). The condition will continue LOW until pulse is trigger again.
The timing period is triggered (started) when trigger input (555 pin 2) is less than 1/3 Vs, this makes the output high (+Vs) and the capacitor C1 starts to charge through resistor R1. Once the time period has started further trigger pulses are ignored.
The threshold input (555 pin 6) monitors the voltage across C1 and when this reaches 2/3 Vs the time period over and the output becomes LOW,
At the same time discharge (555 pin 7) is connected to 0V, discharging the capacitor ready for the next trigger.
8.Astable Mode
Astable multivibrators are also known as Free-running Multivibrator.
Astable do not need trigger pulse for external to change the output.
The period for LOW and HIGH can be calculated based on resistor and capacitor value that connected at outside of timer.
9.Applications
Schmitt trigger
PPM
PWM
Linear Ramp generator
Precision Timing
Pulse Generation
Time Delay Generation
Sequential Timing
Used as a quad timer
10. Conclusion
Hence 555 IC timer can produce very accurate and stable time delays, from microseconds to hours. It can be used with supply voltage varying from 5 to 18 V. Timer can be used in monostable mode of operation or astable mode of operation. Its various applications include waveform generator, missing pulse detector, frequency divider, pulse width modulator, burglar alarm, FSK generator, ramp generator, pulse position modulator etc.
The complete list of thyristor family members include diac (bidirectional diode thyristor), triac (bidirectional triode thyristor), SCR (silicon controlled rectifier), Shockley diode, SCS (silicon controlled switch), SBS (silicon bilateral switch), SUS (silicon unilateral switch) also known as complementary SCR or CSCR, LASCR (light activated SCR), LAS (light activated switch) and LASCS (light activated SCS).
Fully automated railway engine ( to be extended)gaurav ahuja
Self created Android app controls the speed and direction of DC motor based train engine through Bluetooth communication with microcontroller ATMEGA328 arduino.
The schematic presented here is a project of an LED flasher circuit using 555 timer IC. 555 is a famous timer IC
manufactured in 8 pin dip package. In this circuit the IC is used in a flip flop flasher mode. The circuit is using 24 LEDsand will blink each set of 12 LEDs one by one.
Functional block, characteristics of 555 Timer and its PWM application – IC-566 voltage controlled oscillator IC; 565-phase locked loop IC, AD633 Analog multiplier ICs.
SIMULATION OF AN ELECTRONIC DICE CIRCUIT USING LEDs IN PROTEUS SOFTWARE VaishaliVaishali14
The following content consists of the brief details about the topic
INTRODUCTION
CONCEPT OF ASTABLE MULTI VIBRATOR
CONCEPT OF DECADE COUNTER IC4017
CIRCUIT EXPLANATION
CIRCUIT DIAGRAM
VIDEO OF CIRCUIT WORKING
WORKING OF CIRCUIT
INFERENCE
REFERENCE
IC 555 TIMER Introduction, Modes & Application.pptxanindyapal288
Pin 1. – Ground, The ground pin connects the 555 timer to the negative (0v) supply rail.
• Pin 2. – Trigger, The negative input to comparator No 1. A negative pulse on this pin “sets” the internal Flip-flop when the voltage drops below 1/3Vcc causing the output to switch from a “LOW” to a “HIGH” state.
• Pin 3. – Output, The output pin can drive any TTL circuit and is capable of sourcing or sinking up to 200mA of current at an output voltage equal to approximately Vcc – 1.5V so small speakers, LEDs or motors can be connected directly to the output.
• Pin 4. – Reset, This pin is used to “reset” the internal Flip-flop controlling the state of the output, pin 3. This is an active-low input and is generally connected to a logic “1” level when not used to prevent any unwanted resetting of the output.
• Pin 5. – Control Voltage, This pin controls the timing of the 555 by overriding the 2/3Vcc level of the voltage divider network. By applying a voltage to this pin the width of the output signal can be varied independently of the RC timing network. When not used it is connected to ground via a 10nF capacitor to eliminate any noise.
• Pin 6. – Threshold, The positive input to comparator No 2. This pin is used to reset the Flip-flop when the voltage applied to it exceeds 2/3Vcc causing the output to switch from “HIGH” to “LOW” state. This pin connects directly to the RC timing circuit.
• Pin 7. – Discharge, The discharge pin is connected directly to the Collector of an internal NPN transistor which is used to “discharge” the timing capacitor to ground when the output at pin 3 switches “LOW”.
• Pin 8. – Supply +Vcc, This is the power supply pin and for general purpose TTL 555 timers is between 4.5V and 15V.
Simple Automatic Water Level Controller by using ic 555 timer.PRASHANTH RAO
It is a very simple project.present situation all are facing water problems.to over come that water wasteges we are made this project.It is very easy to do and low cost.the cost in between 200 to 300.without human involving it will work.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
2. What is the 555 timer?
• The 555 timer is one of the most remarkable integrated
circuits ever developed. It comes in a single or dual
package and even low power cmos versions exist -
ICM7555.
• Common part numbers are LM555, NE555, LM556,
NE556. The 555 timer consists of two voltage
comparators, a bi-stable flip flop, a discharge transistor,
and a resistor divider network.
4. – The voltage divider (blue) has three equal 5K resistors.
It divides the input voltage (Vcc) into three equal
parts.
– The two comparators (red) are op-amps that compare
the voltages at their inputs and saturate depending
upon which is greater.
• The Threshold Comparator saturates when the voltage at the
Threshold pin (pin 6) is greater than (2/3)Vcc.
• The Trigger Comparator saturates when the voltage at the
Trigger pin (pin 2) is less than (1/3)Vcc
Inside the 555 Timer
5. – The flip-flop (green) is a bi-stable device. It generates two
values, a “high” value equal to Vcc and a “low” value equal to
0V.
• When the Threshold comparator saturates, the flip flop is Reset (R) and
it outputs a low signal at pin 3.
• When the Trigger comparator saturates, the flip flop is Set (S) and it
outputs a high signal at pin 3.
– The transistor (purple) is being used as a switch, it connects pin
7 (discharge) to ground when it is closed.
• When Q is low, Qbar is high. This closes the transistor switch and
attaches pin 7 to ground.
• When Q is high, Qbar is low. This open the switch and pin 7 is no
longer grounded
6. What are the 555 timer
applications?
• Applications include
– precision timing,
– pulse generation,
– sequential timing,
– time delay generation and pulse width modulation
(PWM).
8. • Pin Functions - 8 pin package
• Ground (Pin 1)
• Not surprising this pin is connected directly to ground.
• Trigger (Pin 2)
• This pin is the input to the lower comparator and is used to set the latch, which in
turn causes the output to go high.
• Output (Pin 3)
• Output high is about 1.7V less than supply. Output high is capable of Isource up to
200mA while output low is capable of Isink up to 200mA.
• Reset (Pin 4)
• This is used to reset the latch and return the output to a low state. The reset is an
overriding function. When not used connect to V+.
9. • Control (Pin 5)
• Allows access to the 2/3V+ voltage divider point when the 555 timer is
used in voltage control mode. When not used connect to ground through a
0.01 uF capacitor.
• Threshold (Pin 6)
• This is an input to the upper comparator.
• Discharge (Pin 7)
• This is the open collector to Q14 in figure 4 below.
• V+ (Pin 8)
• This connects to Vcc and the Philips databook states the ICM7555 cmos
version operates 3V - 16V DC while the NE555 version is 3V - 16V DC.
Note comments about effective supply filtering and bypassing this pin
below under "General considerations with using a 555 timer"
10. Types of 555-Timer Circuits
• Astable Multivibrator
puts out a continuous
sequence of pulses
5V
Ra
C
0.01uF
LED
NE555
2
5
3
7
6
4
81
TR
CV
Q
DIS
THR
R
VCCGND
Rb
5V
12
1K
0.01uF
C
R
LED
NE555
2
5
3
7
6
4
81
TR
CV
Q
DIS
THR
R
VCCGND
Monostable Multivibrator (or one-
shot) puts out one pulse each time
the switch is connected
11. • Monostable Multivibrator (One Shot)
+V
-V
-
+
+V
-V
-
+
R
S
Q
Q
3
4
1
7
2
6
8
R
R
R
Control Flip-FlopTrigger Comparator
Threshold Comparator
Output
ResetVcc
Trigger
Monstable Multivibrator
One-Shot
C
Ra
cc
2
V
3
cc
1
V
3
12. Behavior of the Monostable Multivibrator
• The monostable multivibrator is constructed by adding an
external capacitor and resistor to a 555 timer.
• The circuit generates a single pulse of desired duration
when it receives a trigger signal, hence it is also called a
one-shot.
• The time constant of the
resistor-capacitor
combination determines
the length of the pulse.
13. – Used to generate a clean pulse of the correct height
and duration for a digital system
– Used to turn circuits or external components on or off
for a specific length of time.
– Used to generate delays.
– Can be cascaded to create a variety of sequential
timing pulses. These pulses can allow you to time and
sequence a number of related operations.
Uses of the Monostable Multivibrator
14. Astable Pulse-Train Generator (Multivibrator)
+V
-V
-
+
+V
-V
-
+
R
S
Q
Q
3
4
1
7
2
6
8
R
R
R
Control Flip-FlopTrigger Comparator
Threshold Comparator
Output
Vcc
Astable Pulse-Train Generator
C
R1
R2
15. Behavior of the Astable Multivibrator
• The astable multivibrator is simply an oscillator. The astable
multivibrator generates a continuous stream of rectangular off-on
pulses that switch between two voltage levels.
• The frequency of the pulses and their duty cycle are dependent
upon the RC network values.
• The capacitor C charges through the series resistors R1 and R2
with a time constant
(R1 + R2)C.
• The capacitor discharges
through R2 with a time
constant of R2C
16. – Flashing LED’s
– Pulse Width Modulation
– Pulse Position Modulation
– Periodic Timers
Uses of the Astable Multivibrator
17. Flashing LED’s
• 40 LED bicycle light with 20 LEDs flashing
alternately at 4.7Hz
18. Understanding the Astable Mode Circuit
• 555-Timers, like op-amps can be configured in different ways to
create different circuits. We will now look into how this one
creates a train of equal pulses, as shown at the output.
19. First we must examine how capacitors charge
• Capacitor C1 is charged up by current flowing
through R1
• As the capacitor charges up, its voltage increases
and the current charging it decreases, resulting in
the charging rate shown
VV V
R1
1k
U2
TOPEN=0
12
C1
1uF
U1
TCLOSE =0
1 2
0
V1
10V
I
V V
R
V
k
C A P A C I T O R C A P A C I T O R
=
−
=
−1
1
1 0
1
T i me
0 s 1 ms 2 ms 3 ms 4 ms 5 ms 6 ms 7 ms 8 ms 9 ms 1 0 ms
V( U2 : 1 ) V( R1 : 2 ) V( V1 : + )
0 V
2 V
4 V
6 V
8 V
1 0 V
Ca p a c i t o r Vo l t a g e
20. Capacitor Charging Equations
• Capacitor Current
• Capacitor Voltage
• Where the time constant
Ti me
0 s 1 ms 2 ms 3 ms 4 ms 5 ms 6 ms 7 ms 8 ms 9 ms 1 0 ms
I ( R1 ) I ( C1 )
0 A
2 mA
4 mA
6 mA
8 mA
1 0 mA
Ca p a c i t o r a n d Re s i s t o r Cu r r e n t
T i me
0 s 1 ms 2 ms 3 ms 4 ms 5 ms 6 ms 7 ms 8 ms 9 ms 1 0 ms
V( U2 : 1 ) V( R1 : 2 ) V( V1 : + )
0 V
2 V
4 V
6 V
8 V
1 0 V
Ca p a c i t o r Vo l t a g e
I I eo
t
=
−
τ
V V eo
t
= −
−
1 τ
τ = = ⋅ =R C R C m s1 1 1
21. Understanding the equations
• Note that the voltage rises to a little above 6V
in 1ms.
T i me
0 s 1 ms 2 ms 3 ms 4 ms 5 ms 6 ms 7 ms 8 ms 9 ms 1 0 ms
V( U2 : 1 ) V( R1 : 2 ) V( V1 : + )
0 V
2 V
4 V
6 V
8 V
1 0 V
Ca p a c i t o r Vo l t a g e
( ) .1 6 3 21
− =−
e
22. Capacitor Charging and Discharging
• There is a good description of capacitor charging
and its use in 555 timer circuits at
http://www.uoguelph.ca/~antoon/gadgets/555/555.html
23. 555 Timer
• At the beginning of the
cycle, C1 is charged through
resistors R1 and R2. The
charging time constant is
• The voltage reaches
(2/3)Vcc in a time
1)21(693.01arg CRRTt ech +==
1)21(arg CRRech +=τ
24. 555 Timer
• When the voltage on the
capacitor reaches (2/3)Vcc,
a switch (the transistor) is
closed (grounded) at pin 7.
• The capacitor is discharged
to (1/3)Vcc through R2 to
ground, at which time the
switch is opened and the
cycle starts over. 1)2(arg CRedisch =τ
1)2(693.02arg CRTt edisch ==
25. 555 Timer
• The frequency is then given by
f
R R C R R C
=
+ ⋅
=
+ ⋅
1
0 6 9 3 1 2 2 1
1 4 4
1 2 2 1. ( )
.
( )
26. Output voltage high
turns off upper LED
and turns on lower
LED
Capacitor is charging through Ra and Rb
Output is high for
0.693(Ra+Rb)C
555 Animation
http://www.williamson-labs.com/pu-aa-555-timer_slow.htm
27. Output is low
so the upper
LED is on and
the lower LED
is off
Capacitor is discharging
through Rb
Output is low for
0.693(Rb)C
555 Animation
28. PWM: Pulse Width Modulation
• Signal is compared to a sawtooth wave
producing a pulse width proportional to
amplitude
29. What Can Be Done With PWM?
• Question: What happens if voltages like the
ones above are connected to a light bulb?
Answer: The longer the duty cycle, the longer
the light bulb is on and the brighter the light.
Low
Duty Cycle
Medium
Duty Cycle
High
Duty Cycle
30. What Can Be Done With PWM?
• Average power can be controlled
• Average flows can also be controlled by fully opening and
closing a valve with some duty cycle