Temperature Based Fan Controller can be used for reducing the power consumption & also to assist people who are disabled and are unable to control the speed of fan.It may also be used for monitoring changes in environment.
This paper presents an innovative prototype design of electric fan with smart characteristics. This electric fan uses a microcontroller to produce an automation function. It also has a unique double feature designs, such as using 2 fans, 2 Light Emitting Diodes (LED) and 2 sensors. This is to ensure the cooling process operates more efficiently and effectively, especially for a large space application and in hot weather due to global warming. By applying the circuit, it offers a better life for human. It is really practical for senior citizens to make their life simpler. The circuit is also suitable for disabled people who have difficulty to switch on the fan manually. Lastly, the circuit can be manipulated by diversifying its function as a detector, where it can produce an alarm signal when emergency case occurs such as the house or premise is on fire.
Temperature Based Fan Controller can be used for reducing the power consumption & also to assist people who are disabled and are unable to control the speed of fan.It may also be used for monitoring changes in environment.
This paper presents an innovative prototype design of electric fan with smart characteristics. This electric fan uses a microcontroller to produce an automation function. It also has a unique double feature designs, such as using 2 fans, 2 Light Emitting Diodes (LED) and 2 sensors. This is to ensure the cooling process operates more efficiently and effectively, especially for a large space application and in hot weather due to global warming. By applying the circuit, it offers a better life for human. It is really practical for senior citizens to make their life simpler. The circuit is also suitable for disabled people who have difficulty to switch on the fan manually. Lastly, the circuit can be manipulated by diversifying its function as a detector, where it can produce an alarm signal when emergency case occurs such as the house or premise is on fire.
The transducer whose resistance varies because of the environmental effects such type of transducer is known as the resistive transducer. The change in resistance is measured by the ac or dc measuring devices. The resistive transducer is used for measuring the physical quantities like temperature, displacement, vibration etc.
The measurement of the physical quantity is quite difficult. The resistive transducer converts the physical quantities into variable resistance which is easily measured by the meters. The process of variation in resistance is widely used in the industrial applications.
The resistive transducer can work both as the primary as well as the secondary transducer. The primary transducer changes the physical quantities into a mechanical signal, and secondary transducer directly transforms it into an electrical signal.
Working Principle of Resistive Transducer
The resistive transducer element works on the principle that the resistance of the element is directly proportional to the length of the conductor and inversely proportional to the area of the conductor. equation-1
Where R – resistance in ohms.
A – cross-section area of the conductor in meter square.
L – Length of the conductor in meter square.
ρ – the resistivity of the conductor in materials in ohm meter.
The resistive transducer is designed by considering the variation of the length, area and resistivity of the metal.
Applications of Resistive Transducer
The following are the applications of the resistive transducer.
Potentiometer – The translation and rotatory potentiometer are the examples of the resistive transducers. The resistance of their conductor varies with the variation in their lengths which is used for the measurement of displacement.
Strain gauges – The resistance of their semiconductor material changes when the strain occurs on it. This property of metals is used for the measurement of the pressure, force-displacement etc.
Resistance Thermometer – The resistance of the metals changes because of changes in temperature. This property of conductor is used for measuring the temperature.
Thermistor – It works on the principle that the temperature coefficient of the thermistor material varies with the temperature. The thermistor has the negative temperature coefficient. The Negative temperature coefficient means the temperature is inversely proportional to resistance.
LINEAR POTENTIOMETER Potentiometers are electrical devices which are a form of variable resistance.
It consists of a sliding contact which moves over the length of a resistance element. This sliding contact connects to a plunger, which links to the object whose displacement is to be measured.
Referring to the electrical circuit shown here, An input voltage Xt is applied across the whole resistance element, at points A and C. The output voltage, Xi , is measured between the sliding contact at point B and the end of the resistance element at point C. A linear relationship exists between the input voltage Xt, output voltage Xi and the distance BC.
ANGULAR POTENTIOMETER Rotary or angular potentiometers measure angular displacement .
This project proposes automatic detection of human and energy saving room architecture to reduce standby power consumption and to make the temperature of the room easily controllable with an IR sensor and Lm35 temperature sensor using air conditioner . The proposed auto-detection of human done using the IR sensor to indicate the entering or exit ofthe persons. Microcontroller continuously monitors the infrared receiver. When any object pass throughthe IR receiver then the IR rays falling on the receiver are obstructed, this obstruction is sensed by the microcontroller ATMEGA16.When the temperature of the room is varied then the lm35 temperature sensor converts this temperature change into voltage which is then sensed by the microcontroller ATMEGA16 .
In such cases our project is aimed at starting one ac among both depending upon the temperature value at a particular room .If the temperature on the particular room is above certain range then the AC in that room will start up and during this time the AC in the other room will remain switched off. When the temperature goes below 25 degree in the room where AC is already on will be switched off automatically. Then if the temperature on the other room during the time is above 30degree then the AC in that room will start up and vice versa .The second feature of our project is aimed at switching of the AC automatically when there is absence of human beings in a particular room .The entire scheme is designed using number of ATMEGA16 microcontrollers , temperature sensors , digital counter ,IR sensors , relay etc.
This project will solve the day-to-day problem where AC’s do not start up due to low voltage generally in rural areas .This will start the AC depending upon the temperature label in a room by sharing the load .Also this project can be extended for controlling the temperature in more rooms in an apartment.
This Presentation can be used by the Students of Engineering who Deals with the Subject INDUSTRIAL INSTRUMENTATION and use it for Refrence (Anyways you Guys will Copy Paste or Download it) ;)
DESIGN OF TEMPERATURE BASED FAN SPEED CONTROL and MONITORING USING ARDUINORatnesh Kumar chaurasia
This practical temperature controller controls the temperature of any device according to its requirement for any industrial application, it also has a feature of remote speed control.
esistance thermometers, also called resistance temperature detectors (RTDs), are sensors used to measure temperature. Many RTD elements consist of a length of fine wire wrapped around a ceramic or glass core but other constructions are also used. The RTD wire is a pure material, typically platinum, nickel, or copper. The material has an accurate resistance/temperature relationship which is used to provide an indication of temperature. As RTD elements are fragile, they are often housed in protective probes.
Resistance thermometers are constructed in a number of forms and offer greater stability, accuracy and repeatability in some cases than thermocouples. While thermocouples use the Seebeck effect to generate a voltage, resistance thermometers use electrical resistance and require a power source to operate. The resistance ideally varies nearly linearly with temperature per the Callendar–Van Dusen equation.
The platinum detecting wire needs to be kept free of contamination to remain stable. A platinum wire or film is supported on a former in such a way that it gets minimal differential expansion or other strains from its former, yet is reasonably resistant to vibration. RTD assemblies made from iron or copper are also used in some applications. Commercial platinum grades exhibit a temperature coefficient of resistance 0.00385/°C (0.385%/°C) (European Fundamental Interval).[7] The sensor is usually made to have a resistance of 100 Ω at 0 °C. This is defined in BS EN 60751:1996 (taken from IEC 60751:1995). The American Fundamental Interval is 0.00392/°C,[8] based on using a purer grade of platinum than the European standard. The American standard is from the Scientific Apparatus Manufacturers Association (SAMA), who are no longer in this standards field. As a result, the "American standard" is hardly the standard even in the US.
Lead-wire resistance can also be a factor; adopting three- and four-wire, instead of two-wire, connections can eliminate connection-lead resistance effects from measurements (see below); three-wire connection is sufficient for most purposes and is an almost universal industrial practice. Four-wire connections are used for the most precise applications.
Introduction of SCADA, Architecture of SCADA, Software and hardware architecture, Components of a SCADA system, Functions of SCADA, Alarms and events, alarm logging, comparision between scada and DCS
DC MOTOR SPEED CONTROL USING ON-OFF CONTROLLER BY PIC16F877A MICROCONTROLLERTridib Bose
This presentation consists the speed control of a dc motor using hardware (microcontroller) by changing the reference voltages logically and minimising errors.
The transducer whose resistance varies because of the environmental effects such type of transducer is known as the resistive transducer. The change in resistance is measured by the ac or dc measuring devices. The resistive transducer is used for measuring the physical quantities like temperature, displacement, vibration etc.
The measurement of the physical quantity is quite difficult. The resistive transducer converts the physical quantities into variable resistance which is easily measured by the meters. The process of variation in resistance is widely used in the industrial applications.
The resistive transducer can work both as the primary as well as the secondary transducer. The primary transducer changes the physical quantities into a mechanical signal, and secondary transducer directly transforms it into an electrical signal.
Working Principle of Resistive Transducer
The resistive transducer element works on the principle that the resistance of the element is directly proportional to the length of the conductor and inversely proportional to the area of the conductor. equation-1
Where R – resistance in ohms.
A – cross-section area of the conductor in meter square.
L – Length of the conductor in meter square.
ρ – the resistivity of the conductor in materials in ohm meter.
The resistive transducer is designed by considering the variation of the length, area and resistivity of the metal.
Applications of Resistive Transducer
The following are the applications of the resistive transducer.
Potentiometer – The translation and rotatory potentiometer are the examples of the resistive transducers. The resistance of their conductor varies with the variation in their lengths which is used for the measurement of displacement.
Strain gauges – The resistance of their semiconductor material changes when the strain occurs on it. This property of metals is used for the measurement of the pressure, force-displacement etc.
Resistance Thermometer – The resistance of the metals changes because of changes in temperature. This property of conductor is used for measuring the temperature.
Thermistor – It works on the principle that the temperature coefficient of the thermistor material varies with the temperature. The thermistor has the negative temperature coefficient. The Negative temperature coefficient means the temperature is inversely proportional to resistance.
LINEAR POTENTIOMETER Potentiometers are electrical devices which are a form of variable resistance.
It consists of a sliding contact which moves over the length of a resistance element. This sliding contact connects to a plunger, which links to the object whose displacement is to be measured.
Referring to the electrical circuit shown here, An input voltage Xt is applied across the whole resistance element, at points A and C. The output voltage, Xi , is measured between the sliding contact at point B and the end of the resistance element at point C. A linear relationship exists between the input voltage Xt, output voltage Xi and the distance BC.
ANGULAR POTENTIOMETER Rotary or angular potentiometers measure angular displacement .
This project proposes automatic detection of human and energy saving room architecture to reduce standby power consumption and to make the temperature of the room easily controllable with an IR sensor and Lm35 temperature sensor using air conditioner . The proposed auto-detection of human done using the IR sensor to indicate the entering or exit ofthe persons. Microcontroller continuously monitors the infrared receiver. When any object pass throughthe IR receiver then the IR rays falling on the receiver are obstructed, this obstruction is sensed by the microcontroller ATMEGA16.When the temperature of the room is varied then the lm35 temperature sensor converts this temperature change into voltage which is then sensed by the microcontroller ATMEGA16 .
In such cases our project is aimed at starting one ac among both depending upon the temperature value at a particular room .If the temperature on the particular room is above certain range then the AC in that room will start up and during this time the AC in the other room will remain switched off. When the temperature goes below 25 degree in the room where AC is already on will be switched off automatically. Then if the temperature on the other room during the time is above 30degree then the AC in that room will start up and vice versa .The second feature of our project is aimed at switching of the AC automatically when there is absence of human beings in a particular room .The entire scheme is designed using number of ATMEGA16 microcontrollers , temperature sensors , digital counter ,IR sensors , relay etc.
This project will solve the day-to-day problem where AC’s do not start up due to low voltage generally in rural areas .This will start the AC depending upon the temperature label in a room by sharing the load .Also this project can be extended for controlling the temperature in more rooms in an apartment.
This Presentation can be used by the Students of Engineering who Deals with the Subject INDUSTRIAL INSTRUMENTATION and use it for Refrence (Anyways you Guys will Copy Paste or Download it) ;)
DESIGN OF TEMPERATURE BASED FAN SPEED CONTROL and MONITORING USING ARDUINORatnesh Kumar chaurasia
This practical temperature controller controls the temperature of any device according to its requirement for any industrial application, it also has a feature of remote speed control.
esistance thermometers, also called resistance temperature detectors (RTDs), are sensors used to measure temperature. Many RTD elements consist of a length of fine wire wrapped around a ceramic or glass core but other constructions are also used. The RTD wire is a pure material, typically platinum, nickel, or copper. The material has an accurate resistance/temperature relationship which is used to provide an indication of temperature. As RTD elements are fragile, they are often housed in protective probes.
Resistance thermometers are constructed in a number of forms and offer greater stability, accuracy and repeatability in some cases than thermocouples. While thermocouples use the Seebeck effect to generate a voltage, resistance thermometers use electrical resistance and require a power source to operate. The resistance ideally varies nearly linearly with temperature per the Callendar–Van Dusen equation.
The platinum detecting wire needs to be kept free of contamination to remain stable. A platinum wire or film is supported on a former in such a way that it gets minimal differential expansion or other strains from its former, yet is reasonably resistant to vibration. RTD assemblies made from iron or copper are also used in some applications. Commercial platinum grades exhibit a temperature coefficient of resistance 0.00385/°C (0.385%/°C) (European Fundamental Interval).[7] The sensor is usually made to have a resistance of 100 Ω at 0 °C. This is defined in BS EN 60751:1996 (taken from IEC 60751:1995). The American Fundamental Interval is 0.00392/°C,[8] based on using a purer grade of platinum than the European standard. The American standard is from the Scientific Apparatus Manufacturers Association (SAMA), who are no longer in this standards field. As a result, the "American standard" is hardly the standard even in the US.
Lead-wire resistance can also be a factor; adopting three- and four-wire, instead of two-wire, connections can eliminate connection-lead resistance effects from measurements (see below); three-wire connection is sufficient for most purposes and is an almost universal industrial practice. Four-wire connections are used for the most precise applications.
Introduction of SCADA, Architecture of SCADA, Software and hardware architecture, Components of a SCADA system, Functions of SCADA, Alarms and events, alarm logging, comparision between scada and DCS
DC MOTOR SPEED CONTROL USING ON-OFF CONTROLLER BY PIC16F877A MICROCONTROLLERTridib Bose
This presentation consists the speed control of a dc motor using hardware (microcontroller) by changing the reference voltages logically and minimising errors.
final Year Projects, Final Year Projects in Chennai, Software Projects, Embedded Projects, Microcontrollers Projects, DSP Projects, VLSI Projects, Matlab Projects, Java Projects, .NET Projects, IEEE Projects, IEEE 2009 Projects, IEEE 2009 Projects, Software, IEEE 2009 Projects, Embedded, Software IEEE 2009 Projects, Embedded IEEE 2009 Projects, Final Year Project Titles, Final Year Project Reports, Final Year Project Review, Robotics Projects, Mechanical Projects, Electrical Projects, Power Electronics Projects, Power System Projects, Model Projects, Java Projects, J2EE Projects, Engineering Projects, Student Projects, Engineering College Projects, MCA Projects, BE Projects, BTech Projects, ME Projects, MTech Projects, Wireless Networks Projects, Network Security Projects, Networking Projects, final year projects, ieee projects, student projects, college projects, ieee projects in chennai, java projects, software ieee projects, embedded ieee projects, "ieee2009projects", "final year projects", "ieee projects", "Engineering Projects", "Final Year Projects in Chennai", "Final year Projects at Chennai", Java Projects, ASP.NET Projects, VB.NET Projects, C# Projects, Visual C++ Projects, Matlab Projects, NS2 Projects, C Projects, Microcontroller Projects, ATMEL Projects, PIC Projects, ARM Projects, DSP Projects, VLSI Projects, FPGA Projects, CPLD Projects, Power Electronics Projects, Electrical Projects, Robotics Projects, Solor Projects, MEMS Projects, J2EE Projects, J2ME Projects, AJAX Projects, Structs Projects, EJB Projects, Real Time Projects, Live Projects, Student Projects, Engineering Projects, MCA Projects, MBA Projects, College Projects, BE Projects, BTech Projects, ME Projects, MTech Projects, M.Sc Projects, Final Year Java Projects, Final Year ASP.NET Projects, Final Year VB.NET Projects, Final Year C# Projects, Final Year Visual C++ Projects, Final Year Matlab Projects, Final Year NS2 Projects, Final Year C Projects, Final Year Microcontroller Projects, Final Year ATMEL Projects, Final Year PIC Projects, Final Year ARM Projects, Final Year DSP Projects, Final Year VLSI Projects, Final Year FPGA Projects, Final Year CPLD Projects, Final Year Power Electronics Projects, Final Year Electrical Projects, Final Year Robotics Projects, Final Year Solor Projects, Final Year MEMS Projects, Final Year J2EE Projects, Final Year J2ME Projects, Final Year AJAX Projects, Final Year Structs Projects, Final Year EJB Projects, Final Year Real Time Projects, Final Year Live Projects, Final Year Student Projects, Final Year Engineering Projects, Final Year MCA Projects, Final Year MBA Projects, Final Year College Projects, Final Year BE Projects, Final Year BTech Projects, Final Year ME Projects, Final Year MTech Projects, Final Year M.Sc Projects, IEEE Java Projects, ASP.NET Projects, VB.NET Projects, C# Projects, Visual C++ Projects, Matlab Projects, NS2 Projects, C Projects, Microcontroller Projects, ATMEL Projects, PIC Projects, ARM Projects, DSP Projects, VLSI Projects, FPGA Projects, CPLD Projects, Power Electronics Projects, Electrical Projects, Robotics Projects, Solor Projects, MEMS Projects, J2EE Projects, J2ME Projects, AJAX Projects, Structs Projects, EJB Projects, Real Time Projects, Live Projects, Student Projects, Engineering Projects, MCA Projects, MBA Projects, College Projects, BE Projects, BTech Projects, ME Projects, MTech Projects, M.Sc Projects, IEEE 2009 Java Projects, IEEE 2009 ASP.NET Projects, IEEE 2009 VB.NET Projects, IEEE 2009 C# Projects, IEEE 2009 Visual C++ Projects, IEEE 2009 Matlab Projects, IEEE 2009 NS2 Projects, IEEE 2009 C Projects, IEEE 2009 Microcontroller Projects, IEEE 2009 ATMEL Projects, IEEE 2009 PIC Projects, IEEE 2009 ARM Projects, IEEE 2009 DSP Projects, IEEE 2009 VLSI Projects, IEEE 2009 FPGA Projects, IEEE 2009 CPLD Projects, IEEE 2009 Power Electronics Projects, IEEE 2009 Electrical Projects, IEEE 2009 Robotics Projects, IEEE 2009 Solor Projects, IEEE 2009 MEMS Projects, IEEE 2009 J2EE P
Arm cortex ( lpc 2148 ) based motor speed control Uday Wankar
The project is designed to control the speed of a DC and AC motor using an ARM7 LPC2148 processor. The speed of motor is directly proportional to the voltage applied across its terminals. Hence, if voltage across motor terminal is varied, then speed can also be varied. This project uses the above principle to control the speed of the motor by varying the duty cycle of the pulses applied to it, popularly known as PWM control. The project uses input button interfaced to the processor, which are used to control the speed of motor. Pulse Width Modulation is generated at the output by the microcontroller as per the program. The program is written in Embedded C.
The average voltage given or the average current flowing through the motor will change depending on the duty cycle, ON and OFF time of the pulses, so the speed of the motor will change. A motor driver IC is interfaced to the ARM7 LPC2148 processor board for receiving PWM signals and delivering desired output for speed control. Further the project can be enhanced by using power electronic devices such as IGBTs to achieve speed control higher capacity industrial motors.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
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.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
3. WORKING PRINCIPLE
The working principle of this programmable ac power control
using PIC microcontroller device is very simple, its works on the
principle of firing angle change of thyristor. The output power can
be checked with the brightness or intensity of the lamp. AC power
could be changed from 1% to 100% when ac power is changed
then the brightness of output lamp is automatically changed.
Zero crossing detection is very important, especially in power
control circuits employing thyristors.The PIC 16F877A detects the
zero crossing using the RB0/INT external interrupt function. In
phase angle control, a gate pulse is sent to the triac. This is
sent at a time between one zero crossing and the next. After
a certain time, the gating signal is given to the triac and it
turns on. The triac then stays on until the current through it
becomes zero (natural line commutation). How long the triac
is on, is, in turn, determined by the delay time between the
zero-crossing and the applying of the triac gating signal.
4. PIC DEVELOPMENT BOARD
With this board we can develop and prototype with PIC (40 pin)
microcontrollers. The board have User buttons and status LEDs. The
bridge rectifire allow this board to be powered with both AC and DC
power supply adapters.
Features
1. PIC Development Board for Microchip any 40 PIN PIC Series like.
16FXXX, 18FXXX (EX. 16F877A - 40 PIN).
2. ICSP Socket for Programming through PICKIT2 or PICKIT3
3. On board Regulated Power Supply 5v,12v supplies
4. Easy to test with Burg Connecters wires
5. An RS232 Serial Port
6. 7 Segment Multiplexed Display
7. DC Power Supply Connector(12v Ac or Dc)
8. READY INTERFACE For LCD display 2linex6Character
9. 24Cxx (I2C) (EEPROM)
10. RTC (DS1307)
11. 4 LED array
13. 4 Interrupt Switches
14. ADC Interface Support
6. PICKIT 2 PROGRAMMER
PICkit 2 Debug Express allows in-circuit debugging on selected
PICmicro microcontroller units (MCUs). In-circuit debugging allows the
designer to run, examine, and modify the program while the PICmicro
MCU is embedded in the hardware, thereby assisting the designer in
debugging the firmware and hardware together. Debug Express interacts
with MPLAB IDE software.
7. K- TYPE THERMOCOUPLE
Features
Working voltage: DC 5V
Operating Current: 50mA
Temperature measuring range: -2°C to 800 °C [Test
procedure for 2-800 °C]
Temperature measurement accuracy: ± 1.5 °C
Temperature resolution: 0.25 °C
The output mode: SPI digital signal
Storage temperature: -20 ~ 80 °C
Type-K Thermocouple (Chromel/Alumel) Type K
thermocouples usually work in most applications as they are
nickel based and exhibit good corrosion resistance. It is the most
common sensor calibration type providing the widest operating
temperature range.
8. 16x2 LCD DISPLAY
LCD (Liquid Crystal Display) screen is an
electronic display module and find a wide range of
applications. A 16x2 LCD display is very basic module and is
very commonly used in various devices and circuits. These
modules are preferred over seven segments and other multi
segment LEDs.
9. Power Supply
The 220V- 50Hz ac voltage is stepped down using a 12-0-12V
transformer and then fed to a bridge rectifier. The output will
contain dc components as well as ac components. A filter
capacitor is used to produce a pure dc supply and is applied to a
7805 voltage regulator IC. Thus the circuit will produce a 5V
supply to power up the other circuits and the PIC
microcontroller,
10. Zero Crossing Detector
A Zero Crossing Detector Circuit is used to track the changing in the sine
waveform from positive to negative or vice versa while it crosses Zero voltage.
The supply from ac source is rectified using a bridge rectifier and then applied
to an optocoupler 4N25. The optocoupler have an led which when turned ON, it
activates the transistor. When the transistor is turned on, the 5V supply passes to
the ground. In other words, during the zero point of sine wave, a HIGH output is
produced which will be fed to the microcontroller.
11. TRIAC Firing Angle Control Circuit
TRIAC, from triode for alternating current, is a generic trademark for a three
terminal electronic component that conducts current in either direction when
triggered. The triac acts as a switch which allows AC supply to pass through it
when a gate signal is applied. Here the microcontroller generates PWM signal
that is applied to the gate terminal of traic BT136 using triac driven optocoupler
MOC3021. The optocoupler not only drives the triac but also isolates the
microcontroller from the AC circuitry.
13. .
Thermocouple Compensation
The Thermocouple voltage difference is amplified with an
LM358 in non-inverting amplifier configuration. It is
configured for significant gain in order to get the µV
reading into the 0-5V scale readable with an
microcontroller analog input.
The second op amp in the LM358 is used to buffer the
reading - really unnecessary in this configuration as the
microcontroller analog input presents a fairly high
impedence load.
14. Applications
• Temperature controllers are used in ovens and in heat-treating applications
within furnaces, ceramic kilns, boilers, and heat exchangers.
• Temperature control in the plastics industry is common on portable chillers,
hoppers and dryers
• Temperature controllers are used in the healthcare industry to increase the
accuracy of temperature control. Common equipment using temperature
controllers includes laboratory and test equipment, autoclaves, incubators,
refrigeration equipment.
• Common food processing applications involving temperature controllers
include brewing, blending, sterilization, and cooking and baking ovens.