LDR-experimentation.pdf
pg. 1
COVENTRY UNIVERSITY
Faculty Of Engineering & Computing
AAEE
Light Depended Resistors (LDRs)
Introduction
The light dependent resistor, LDR, is known by many other names such as photoresistor,
photoconductor, photoconductive cell, or simply the photocell. These devices were discovered by an
English electrical engineer Willoughby Smith back in 1873. Smith’s main line of work in 1848 was the
laying of underwater telegraph cables. He developed a method of testing an underwater cable as it
was being laid. One of the insulation materials used for the cable was selenium. Upon investigation
of the properties of the selenium insulator he discovered that the conductivity properties of the
material were affected by light. He published his findings in 1873.
Since then many variants of photoconductive devices have been made. Other LDRs have been made
using materials including cadmium sulphide, lead sulphide, and the more commonly used
semiconductor materials including germanium, silicon and gallium arsenide.
The most popular material used in making LDRs is cadmium sulphide (CdS).
The LDR finds many uses as a low cost photo sensitive element and was used for many years in
photographic light meters as well as in other applications such as lighting controls for street lamps
etc.
Basic structure of an LDR
There are many ways in which light dependent resistors can be manufactured. Essentially the LDR
consists of a resistive material sensitive to light. The photo resistive element comprises section of the
material with contacts at either end. Although many of the materials used for light dependent
resistors are semiconductors, when used as a photo resistor, they are used only as a resistive and
they are purely passive.
A typical structure for a light dependent or photo resistor uses an active semiconductor layer that is
deposited on an insulating substrate. The semiconductor is normally lightly doped to enable it to have
the required level of conductivity. Contacts are then placed either side of the exposed area.
Fig 1 (a,b,c) Close-Up of an LDR (a) Cadmium sulphate (b) and LDR symbol (c)
(a)
(b)
(c)
pg. 2
In many instances the area between the contacts is in the form of a zig zag, or interdigital pattern.
This maximises the exposed area and by keeping the distance between the contacts small it enhances
the gain (see Fig.1 (a).
Although other devices such as photodiodes or photo-transistors can also be used for light sensing
applications, LDRs are a particularly convenient electronic component to use. They provide large
change in resistance for changes in light level. They are of comparatively speaking of a lower cost as
compared to other light responding devices.
How an LDR works
It is relatively easy to understand the basics of how an LDR works without delving into complicated
explanations. It is first necessary to understand that an electrical ...
Measuring the amount of current drawn by a load in LDR circuit when in light ...SumitDutta58
This is a full Project Report with Demonstration available for measurement of Electric Current for Measurement and Instrument students, for a brief Idea and source for "How to Approach" for an LDR Experiment.
The document describes an experiment to study how the current flowing through a light dependent resistor (LDR) varies with changes in the power and distance of an incandescent light source. The LDR's resistance decreases when exposed to light, increasing the current. The experiment found that the current increased as the light source's power increased or its distance from the LDR decreased. Common applications of LDRs include camera light meters, photocopying machines, and automatic lighting controls.
AUTOMATIC LIGHT CONTROL BY USING MICROCONTROLLER BASED LDRNathan Mathis
This document describes a project on automatic light control using a microcontroller-based light dependent resistor (LDR) by two students at Daffodil International University in Bangladesh. It was submitted in partial fulfillment of their Bachelor of Science degree in electrical and electronics engineering. The project involved designing a circuit to automatically control lights based on ambient light levels detected by an LDR. Key components of the circuit included an LDR, microcontroller, transistor, relay, and other electronic components. The aim was to develop an energy efficient automatic lighting system that eliminates the need for manual operation.
The document describes a shadow intruder alarm circuit that uses a light dependent resistor (LDR). The circuit can detect movement of a person near it based on changes in light/shadow falling on the LDR, and trigger an alarm. It has applications for security at shops, warehouses, and homes. The circuit works by sounding an alarm when the LDR resistance increases due to a shadow blocking light on it. This allows the circuit to detect intruders without needing an aligned light beam. The document provides details on the components used in the circuit like the LDR, transistor, resistors, capacitors, and relay. It also gives background information on LDRs and their applications in security and other devices.
The document describes an electronic letter box circuit that uses a light dependent resistor (LDR) to detect when a letter is placed inside the box. The circuit uses a 555 timer IC connected as a comparator. It also includes an LDR, LEDs, resistors, a variable resistor, battery, and switch. When light falls on the LDR, its resistance decreases, causing the 555 output to trigger one LED. But when a letter blocks the light, the LDR resistance increases, causing the 555 to trigger a different LED to indicate a letter is present. The circuit uses few components and little power, making it suitable for portable use in a letter box.
The document describes a circuit project using an LDR (light dependent resistor) on a breadboard that acts as a dark sensor. The circuit uses two transistors, an LED, an LDR, resistors, a battery, and a buzzer. When light falls on the LDR, the LED and buzzer turn off, and when light is blocked from the LDR, the LED glows and buzzer sounds. The document provides details on the components used, breadboard connections, circuit diagrams, and the working of the circuit.
A Measurements Project on Light Detection sensorsvrohith 9
The main aim of this project is to saving system with LDR this is to save the power. We want to save power automatically instead of doing manual. So it’s easy to cost effectiveness. This saved power can be used in some other cases. So in villages, towns etc. we can design intelligent systems for the usage of light or we can also use this to reduce the electricity bill of our home. This project can also be used for security of the houses, banks, etc.
Automatic street light using ldr and relayShivam Raidas
The circuit uses an LDR, operational amplifier IC CA3140, and other components to automatically control street lights. The LDR's resistance varies with light intensity, affecting the voltage inputs to the IC. During the day when the LDR resistance is low, the IC output is low and the transistor cuts off, turning off lights. At night when the LDR resistance increases, the IC output goes high, turning on the transistor and lights. A relay is used to control higher power street lights since it can isolate the small IC signal from the larger street light loads.
Measuring the amount of current drawn by a load in LDR circuit when in light ...SumitDutta58
This is a full Project Report with Demonstration available for measurement of Electric Current for Measurement and Instrument students, for a brief Idea and source for "How to Approach" for an LDR Experiment.
The document describes an experiment to study how the current flowing through a light dependent resistor (LDR) varies with changes in the power and distance of an incandescent light source. The LDR's resistance decreases when exposed to light, increasing the current. The experiment found that the current increased as the light source's power increased or its distance from the LDR decreased. Common applications of LDRs include camera light meters, photocopying machines, and automatic lighting controls.
AUTOMATIC LIGHT CONTROL BY USING MICROCONTROLLER BASED LDRNathan Mathis
This document describes a project on automatic light control using a microcontroller-based light dependent resistor (LDR) by two students at Daffodil International University in Bangladesh. It was submitted in partial fulfillment of their Bachelor of Science degree in electrical and electronics engineering. The project involved designing a circuit to automatically control lights based on ambient light levels detected by an LDR. Key components of the circuit included an LDR, microcontroller, transistor, relay, and other electronic components. The aim was to develop an energy efficient automatic lighting system that eliminates the need for manual operation.
The document describes a shadow intruder alarm circuit that uses a light dependent resistor (LDR). The circuit can detect movement of a person near it based on changes in light/shadow falling on the LDR, and trigger an alarm. It has applications for security at shops, warehouses, and homes. The circuit works by sounding an alarm when the LDR resistance increases due to a shadow blocking light on it. This allows the circuit to detect intruders without needing an aligned light beam. The document provides details on the components used in the circuit like the LDR, transistor, resistors, capacitors, and relay. It also gives background information on LDRs and their applications in security and other devices.
The document describes an electronic letter box circuit that uses a light dependent resistor (LDR) to detect when a letter is placed inside the box. The circuit uses a 555 timer IC connected as a comparator. It also includes an LDR, LEDs, resistors, a variable resistor, battery, and switch. When light falls on the LDR, its resistance decreases, causing the 555 output to trigger one LED. But when a letter blocks the light, the LDR resistance increases, causing the 555 to trigger a different LED to indicate a letter is present. The circuit uses few components and little power, making it suitable for portable use in a letter box.
The document describes a circuit project using an LDR (light dependent resistor) on a breadboard that acts as a dark sensor. The circuit uses two transistors, an LED, an LDR, resistors, a battery, and a buzzer. When light falls on the LDR, the LED and buzzer turn off, and when light is blocked from the LDR, the LED glows and buzzer sounds. The document provides details on the components used, breadboard connections, circuit diagrams, and the working of the circuit.
A Measurements Project on Light Detection sensorsvrohith 9
The main aim of this project is to saving system with LDR this is to save the power. We want to save power automatically instead of doing manual. So it’s easy to cost effectiveness. This saved power can be used in some other cases. So in villages, towns etc. we can design intelligent systems for the usage of light or we can also use this to reduce the electricity bill of our home. This project can also be used for security of the houses, banks, etc.
Automatic street light using ldr and relayShivam Raidas
The circuit uses an LDR, operational amplifier IC CA3140, and other components to automatically control street lights. The LDR's resistance varies with light intensity, affecting the voltage inputs to the IC. During the day when the LDR resistance is low, the IC output is low and the transistor cuts off, turning off lights. At night when the LDR resistance increases, the IC output goes high, turning on the transistor and lights. A relay is used to control higher power street lights since it can isolate the small IC signal from the larger street light loads.
This document describes the circuit diagram and components of a 100 watt inverter. It uses an IC CD4047 and MOSFET IRF540. The CD4047 produces two out-of-phase pulse trains that control the gates of the MOSFETs, allowing current to alternately flow through the top and bottom halves of the transformer primary. This converts the DC battery power to an AC output. The circuit is simple and low-cost. Resistors prevent the IC from being loaded by the MOSFETs. The document also provides details on the operation and specifications of key components like resistors, capacitors, and the CD4047 IC.
This document provides instructions for an embedded systems lab experiment involving controlling LED lights using a light dependent resistor (LDR) sensor and a PIC18F4550 microcontroller. The objectives are to learn how to design embedded systems circuits, initialize a microcontroller, and program the PIC18F4550 to control LEDs based on light intensity readings from the LDR sensor. Students will write a program to read analog voltage values from the LDR, map those values to 3 modes of LED operation, and switch the LEDs accordingly. They will test their designed circuit and program, and answer questions about varying the light intensity, measuring resistances and voltages for each mode.
The document discusses the working of a light dependent resistor (LDR) and designing a circuit to demonstrate its varying resistance. It begins by introducing LDRs and explaining that their resistivity decreases when light is absorbed. It then describes building a circuit using an LDR, resistor, battery, LED, and breadboard. The circuit works by changing the LDR's resistance based on light intensity, which controls current flow through the LED. Finally, applications of LDRs include light sensors for street lamps, alarms, and automatic controls that require detecting light levels.
This document discusses the components used in an automatic street light control circuit using a light dependent resistor (LDR). It includes:
1) An overview of the LDR and how its resistance changes with light intensity, allowing it to act as a switch.
2) Details of the other components - a triac, diac, resistors, capacitors - and how they work together in the circuit. When light falls on the LDR, it prevents the triac from triggering, turning off the street light. In darkness, the triac is triggered, turning on the light.
3) The procedure, observations and results of testing the automatic street light control circuit using an LDR. The circuit successfully
To measure the intensity of light using LDR sensor by calibrating voltage wit...Ankita Tiwari
The document describes an experiment to measure light intensity using an LDR sensor calibrated with LabVIEW. An Arduino board reads the voltage across the LDR and LabVIEW converts it to lux using equations relating resistance, voltage and light intensity. LabVIEW establishes a front panel and block diagram to communicate with the Arduino, send new delay interval values to control motor speed, and clear registers to avoid data overflow. The experiment successfully measured light intensity by calibrating LDR voltage to lux in LabVIEW.
This document describes an automatic street light system that uses a light dependent resistor (LDR) and transistor to automatically switch a street light on and off. The main components are an LDR, transistor, resistors, LED, battery and PCB board. The LDR senses light levels and changes its resistance accordingly. When it gets dark, the LDR's resistance increases which turns on the transistor and lights. During the day when light hits the LDR, its resistance decreases and the lights switch off. The system provides energy savings, low cost operation, and automated control of street lights based on light levels.
Synopsis of solar tracker and charging monitorTarun Arora
This document provides an overview and objectives of a minor project on developing a solar tracker and charging monitor system. The solar tracker uses light dependent resistors and a motor driver IC to adjust a solar panel to maintain optimal sunlight exposure throughout the day. The charging monitor uses an LED voltmeter IC to indicate the charge level of a solar power battery. The project will involve designing and implementing the circuitry on a PCB board, including ICs, resistors, capacitors, and other components to achieve the solar tracking and battery monitoring functions.
This document provides an overview of infrared technology and its applications in sensing and remote controls. It describes the basic components of an infrared detection system, including infrared sources like LEDs, transmission media, optical components, infrared detectors, and signal processing. It then discusses the specific components used in an example infrared obstacle detection circuit, including an IR LED, photodiode, op-amp, and potentiometer for threshold adjustment. The circuit detects objects by measuring changes in received infrared light intensity.
This document describes the design and development of a light intensity meter circuit. The circuit uses a light dependent resistor, voltage divider network, operational amplifiers, analog to digital conversion, and a priority encoder to measure light levels. The output is displayed on a 7-segment display. Key components include an LM324 op-amp, LDR light sensor, 74LS147 priority encoder, and 74LS48 BCD to 7-segment decoder. The circuit aims to provide an inexpensive and accurate way to measure light intensity with a range of 0-2000 lux.
“Microcontroller Based Substation Monitoring system with gsm modem”.Priya Rachakonda
• The system is used for transmitting the message to predefined number about the
status of electrical parameters such as voltage, current, temperature etc., to improve
the quality of power.
• Studied about the protection, monitoring and control of a power system.
components.pptx good for used componentsThyaguThyag
The document provides information about several different sensors:
- Ultrasonic sensors transmit ultrasonic waves and detect their reflection to measure distance. The HC-SR04 module can measure distances from 2-200 cm.
- Infrared sensors detect infrared light for proximity detection. They have an IR LED transmitter and photodiode receiver.
- LDR sensors have a resistance that decreases with increasing light intensity, allowing them to be used in light-sensing circuits.
- The DHT11 sensor measures both temperature and humidity using a thermistor and capacitive humidity sensor.
- Alcohol sensors like the MQ3 use a metal oxide semiconductor to detect alcohol concentrations between 25-500 ppm based on changes in resistance
This document describes how to build an automatic light switch using a Wheatstone bridge circuit. The circuit uses an LDR, transistor, op-amp, potentiometer, and resistors. An LDR's resistance decreases with light, allowing it to control the circuit. The Wheatstone bridge compares the voltage drop across the LDR and resistor arms. When light hits the LDR, its lower resistance unbalances the bridge, triggering the op-amp and transistor to power an LED, functioning as an automatic light switch. Applications include street lights, light meters, and automatic room lighting.
This document discusses basic electronic components, their functions, and how to construct simple circuits using a breadboard. It defines components like LEDs, resistors, light-dependent resistors, transistors, and batteries. It provides examples of these components' symbols and evaluates readers' understanding through multiple choice and identification questions. The objectives are to understand basic circuits, build simple circuits using a breadboard, and appreciate breadboarding's importance for temporarily constructing electronic circuits.
This document provides instructions for an experiment using a Wheatstone bridge circuit with a light dependent resistor to detect light intensity changes. The objectives are to design, construct, and test the Wheatstone bridge light detector circuit. The circuit diagram shows a Wheatstone bridge using a light dependent resistor, resistors, potentiometer, transistor, and relay. When light falls on the light dependent resistor, its resistance decreases, causing the transistor to turn on and illuminate an LED, showing that light was detected. Students are to write a laboratory report explaining Wheatstone bridge theory, discussing circuit fabrication and testing, and preparing a presentation on the project.
An LDR, or light dependent resistor, is a light-sensitive device whose resistivity decreases with increasing intensity of light. It is made from semiconductor materials with a high resistance. When light photons having greater energy than the material's band gap fall on the device, electrons in the valence band are excited to the conduction band, increasing the number of charge carriers and reducing resistance. LDRs are classified as intrinsic, made of pure semiconductors, or extrinsic, made with impurity dopants that decrease the required photon energy. An LDR can be used in a circuit with a transistor so that light turning the LDR on will activate the transistor and power an LED.
This document presents a high-efficiency LED driving circuit based on a buck converter topology. The circuit is designed to operate under a wide input voltage range of 85V to 265V and drive a series of high-power LEDs. The operation principles and power loss factors of the circuit are analyzed in detail. A prototype is designed and tested to drive 16 series-connected LUMILEDS LEDs, achieving an efficiency of 92% at 350mA output current. Experimental results show the circuit achieves over 90% efficiency under variable input and output voltages, validating the design.
IoT Based Infrared Remote Controlled AC Fan Regulatorijtsrd
This document describes the design and implementation of an infrared remote controlled AC fan regulator. The regulator uses various electronic components like an IR sensor, monostable multi vibrator, decade counter, transformer, comparator, opto-isolator and TRIAC. It allows users to control an AC fan using any infrared remote control. When a button on the remote is pressed, it transmits an infrared light signal that is received by the IR sensor. The fan speed then increases smoothly through 10 different speed levels. The circuit was simulated and experimentally tested, and worked satisfactorily to remotely control the fan speed.
This document describes an automatic street light control circuit using an LDR that turns lights on and off based on light levels. The circuit uses an LDR, resistors, capacitors, a transistor, and relay. When it gets dark, the resistance of the LDR decreases which causes the transistor to turn on and activate the relay, powering the street lights. When it gets light again, the LDR's resistance increases and the lights turn off. The circuit provides automatic light control with low power consumption.
Automatic street light circuit using ldrSmartxProKits
This document describes an automatic street light circuit that uses an LDR (light dependent resistor) and comparator IC LM393. The LDR detects light levels and the LM393 comparator determines whether the street light should be on or off. When light falls on the LDR, it conducts and the street light stays off. When no light falls on the LDR, it does not conduct and the street light glows continuously until light is detected again. The circuit operates on a 5V DC supply and uses readily available, low-cost components like the LDR to detect light changes and automatically control the street light.
please write a short essay to address the following questions. Lengt.docxDIPESH30
please write a short essay to address the following questions. Length: 500 word count to the minimum.
“Blogs, Twitter, Facebook, and a host of other news and social-media sites have allowed average citizens to become newsmakers. Is this a good or bad thing? Is the increase in citizen journalism leading to inaccuracies in reporting? Or can we trust that Americans will “consider the source” and verify any questionable information they read on a blog?”
Requirements:
1.Word count: 500.
2.Submissions must be in Word format (doc, docx) or Rich Text format (rtf). Attached file sent to my email will not be graded.
3.VeriCite has been activated to prevent plagiarism and no credit will be issued if Similarity Index points to 20% or higher.
.
please write a diary entry from the perspective of a French Revoluti.docxDIPESH30
please write a diary entry from the perspective of a French Revolutionary of the Third Estate (bourgeoisie, worker, or peasant), a member of the First Estate (clergy) or a member of the Second Estate (nobles). Your entry should have a well established mood, or writing that evokes certain feelings or emotions in readers through words and descriptions. Some examples of mood through setting, diction, and tone can be found
HERE
.
In addition, your journal should incorporate at least
THREE
of the following vocabulary terms:
Louis XVI
Estates-General
National Assembly
Tennis Court Oath
estate (First, Second, Third)
The Enlightenment
Great Fear
.
More Related Content
Similar to LDR-experimentation.pdfpg. 1 COVENTRY UNIVERSITY .docx
This document describes the circuit diagram and components of a 100 watt inverter. It uses an IC CD4047 and MOSFET IRF540. The CD4047 produces two out-of-phase pulse trains that control the gates of the MOSFETs, allowing current to alternately flow through the top and bottom halves of the transformer primary. This converts the DC battery power to an AC output. The circuit is simple and low-cost. Resistors prevent the IC from being loaded by the MOSFETs. The document also provides details on the operation and specifications of key components like resistors, capacitors, and the CD4047 IC.
This document provides instructions for an embedded systems lab experiment involving controlling LED lights using a light dependent resistor (LDR) sensor and a PIC18F4550 microcontroller. The objectives are to learn how to design embedded systems circuits, initialize a microcontroller, and program the PIC18F4550 to control LEDs based on light intensity readings from the LDR sensor. Students will write a program to read analog voltage values from the LDR, map those values to 3 modes of LED operation, and switch the LEDs accordingly. They will test their designed circuit and program, and answer questions about varying the light intensity, measuring resistances and voltages for each mode.
The document discusses the working of a light dependent resistor (LDR) and designing a circuit to demonstrate its varying resistance. It begins by introducing LDRs and explaining that their resistivity decreases when light is absorbed. It then describes building a circuit using an LDR, resistor, battery, LED, and breadboard. The circuit works by changing the LDR's resistance based on light intensity, which controls current flow through the LED. Finally, applications of LDRs include light sensors for street lamps, alarms, and automatic controls that require detecting light levels.
This document discusses the components used in an automatic street light control circuit using a light dependent resistor (LDR). It includes:
1) An overview of the LDR and how its resistance changes with light intensity, allowing it to act as a switch.
2) Details of the other components - a triac, diac, resistors, capacitors - and how they work together in the circuit. When light falls on the LDR, it prevents the triac from triggering, turning off the street light. In darkness, the triac is triggered, turning on the light.
3) The procedure, observations and results of testing the automatic street light control circuit using an LDR. The circuit successfully
To measure the intensity of light using LDR sensor by calibrating voltage wit...Ankita Tiwari
The document describes an experiment to measure light intensity using an LDR sensor calibrated with LabVIEW. An Arduino board reads the voltage across the LDR and LabVIEW converts it to lux using equations relating resistance, voltage and light intensity. LabVIEW establishes a front panel and block diagram to communicate with the Arduino, send new delay interval values to control motor speed, and clear registers to avoid data overflow. The experiment successfully measured light intensity by calibrating LDR voltage to lux in LabVIEW.
This document describes an automatic street light system that uses a light dependent resistor (LDR) and transistor to automatically switch a street light on and off. The main components are an LDR, transistor, resistors, LED, battery and PCB board. The LDR senses light levels and changes its resistance accordingly. When it gets dark, the LDR's resistance increases which turns on the transistor and lights. During the day when light hits the LDR, its resistance decreases and the lights switch off. The system provides energy savings, low cost operation, and automated control of street lights based on light levels.
Synopsis of solar tracker and charging monitorTarun Arora
This document provides an overview and objectives of a minor project on developing a solar tracker and charging monitor system. The solar tracker uses light dependent resistors and a motor driver IC to adjust a solar panel to maintain optimal sunlight exposure throughout the day. The charging monitor uses an LED voltmeter IC to indicate the charge level of a solar power battery. The project will involve designing and implementing the circuitry on a PCB board, including ICs, resistors, capacitors, and other components to achieve the solar tracking and battery monitoring functions.
This document provides an overview of infrared technology and its applications in sensing and remote controls. It describes the basic components of an infrared detection system, including infrared sources like LEDs, transmission media, optical components, infrared detectors, and signal processing. It then discusses the specific components used in an example infrared obstacle detection circuit, including an IR LED, photodiode, op-amp, and potentiometer for threshold adjustment. The circuit detects objects by measuring changes in received infrared light intensity.
This document describes the design and development of a light intensity meter circuit. The circuit uses a light dependent resistor, voltage divider network, operational amplifiers, analog to digital conversion, and a priority encoder to measure light levels. The output is displayed on a 7-segment display. Key components include an LM324 op-amp, LDR light sensor, 74LS147 priority encoder, and 74LS48 BCD to 7-segment decoder. The circuit aims to provide an inexpensive and accurate way to measure light intensity with a range of 0-2000 lux.
“Microcontroller Based Substation Monitoring system with gsm modem”.Priya Rachakonda
• The system is used for transmitting the message to predefined number about the
status of electrical parameters such as voltage, current, temperature etc., to improve
the quality of power.
• Studied about the protection, monitoring and control of a power system.
components.pptx good for used componentsThyaguThyag
The document provides information about several different sensors:
- Ultrasonic sensors transmit ultrasonic waves and detect their reflection to measure distance. The HC-SR04 module can measure distances from 2-200 cm.
- Infrared sensors detect infrared light for proximity detection. They have an IR LED transmitter and photodiode receiver.
- LDR sensors have a resistance that decreases with increasing light intensity, allowing them to be used in light-sensing circuits.
- The DHT11 sensor measures both temperature and humidity using a thermistor and capacitive humidity sensor.
- Alcohol sensors like the MQ3 use a metal oxide semiconductor to detect alcohol concentrations between 25-500 ppm based on changes in resistance
This document describes how to build an automatic light switch using a Wheatstone bridge circuit. The circuit uses an LDR, transistor, op-amp, potentiometer, and resistors. An LDR's resistance decreases with light, allowing it to control the circuit. The Wheatstone bridge compares the voltage drop across the LDR and resistor arms. When light hits the LDR, its lower resistance unbalances the bridge, triggering the op-amp and transistor to power an LED, functioning as an automatic light switch. Applications include street lights, light meters, and automatic room lighting.
This document discusses basic electronic components, their functions, and how to construct simple circuits using a breadboard. It defines components like LEDs, resistors, light-dependent resistors, transistors, and batteries. It provides examples of these components' symbols and evaluates readers' understanding through multiple choice and identification questions. The objectives are to understand basic circuits, build simple circuits using a breadboard, and appreciate breadboarding's importance for temporarily constructing electronic circuits.
This document provides instructions for an experiment using a Wheatstone bridge circuit with a light dependent resistor to detect light intensity changes. The objectives are to design, construct, and test the Wheatstone bridge light detector circuit. The circuit diagram shows a Wheatstone bridge using a light dependent resistor, resistors, potentiometer, transistor, and relay. When light falls on the light dependent resistor, its resistance decreases, causing the transistor to turn on and illuminate an LED, showing that light was detected. Students are to write a laboratory report explaining Wheatstone bridge theory, discussing circuit fabrication and testing, and preparing a presentation on the project.
An LDR, or light dependent resistor, is a light-sensitive device whose resistivity decreases with increasing intensity of light. It is made from semiconductor materials with a high resistance. When light photons having greater energy than the material's band gap fall on the device, electrons in the valence band are excited to the conduction band, increasing the number of charge carriers and reducing resistance. LDRs are classified as intrinsic, made of pure semiconductors, or extrinsic, made with impurity dopants that decrease the required photon energy. An LDR can be used in a circuit with a transistor so that light turning the LDR on will activate the transistor and power an LED.
This document presents a high-efficiency LED driving circuit based on a buck converter topology. The circuit is designed to operate under a wide input voltage range of 85V to 265V and drive a series of high-power LEDs. The operation principles and power loss factors of the circuit are analyzed in detail. A prototype is designed and tested to drive 16 series-connected LUMILEDS LEDs, achieving an efficiency of 92% at 350mA output current. Experimental results show the circuit achieves over 90% efficiency under variable input and output voltages, validating the design.
IoT Based Infrared Remote Controlled AC Fan Regulatorijtsrd
This document describes the design and implementation of an infrared remote controlled AC fan regulator. The regulator uses various electronic components like an IR sensor, monostable multi vibrator, decade counter, transformer, comparator, opto-isolator and TRIAC. It allows users to control an AC fan using any infrared remote control. When a button on the remote is pressed, it transmits an infrared light signal that is received by the IR sensor. The fan speed then increases smoothly through 10 different speed levels. The circuit was simulated and experimentally tested, and worked satisfactorily to remotely control the fan speed.
This document describes an automatic street light control circuit using an LDR that turns lights on and off based on light levels. The circuit uses an LDR, resistors, capacitors, a transistor, and relay. When it gets dark, the resistance of the LDR decreases which causes the transistor to turn on and activate the relay, powering the street lights. When it gets light again, the LDR's resistance increases and the lights turn off. The circuit provides automatic light control with low power consumption.
Automatic street light circuit using ldrSmartxProKits
This document describes an automatic street light circuit that uses an LDR (light dependent resistor) and comparator IC LM393. The LDR detects light levels and the LM393 comparator determines whether the street light should be on or off. When light falls on the LDR, it conducts and the street light stays off. When no light falls on the LDR, it does not conduct and the street light glows continuously until light is detected again. The circuit operates on a 5V DC supply and uses readily available, low-cost components like the LDR to detect light changes and automatically control the street light.
Similar to LDR-experimentation.pdfpg. 1 COVENTRY UNIVERSITY .docx (20)
please write a short essay to address the following questions. Lengt.docxDIPESH30
please write a short essay to address the following questions. Length: 500 word count to the minimum.
“Blogs, Twitter, Facebook, and a host of other news and social-media sites have allowed average citizens to become newsmakers. Is this a good or bad thing? Is the increase in citizen journalism leading to inaccuracies in reporting? Or can we trust that Americans will “consider the source” and verify any questionable information they read on a blog?”
Requirements:
1.Word count: 500.
2.Submissions must be in Word format (doc, docx) or Rich Text format (rtf). Attached file sent to my email will not be graded.
3.VeriCite has been activated to prevent plagiarism and no credit will be issued if Similarity Index points to 20% or higher.
.
please write a diary entry from the perspective of a French Revoluti.docxDIPESH30
please write a diary entry from the perspective of a French Revolutionary of the Third Estate (bourgeoisie, worker, or peasant), a member of the First Estate (clergy) or a member of the Second Estate (nobles). Your entry should have a well established mood, or writing that evokes certain feelings or emotions in readers through words and descriptions. Some examples of mood through setting, diction, and tone can be found
HERE
.
In addition, your journal should incorporate at least
THREE
of the following vocabulary terms:
Louis XVI
Estates-General
National Assembly
Tennis Court Oath
estate (First, Second, Third)
The Enlightenment
Great Fear
.
Please write the definition for these words and provide .docxDIPESH30
Please write the definition for these words and
provide two
examples
for each one
The definition should relate to “linguistic form“ / grammar
See attached file. you have
three hours and an half
to do the assignemnt
.
Please view the filmThomas A. Edison Father of Invention, A .docxDIPESH30
Please view the film:
Thomas A. Edison: Father of Invention
, A & E Television (New York, NY: A & E Television Networks, 1996); Available on the Hagerty Library catalogue at: http://records.library.drexel.edu/record=b2133926~S9
And discuss:
Edison is portrayed rather herocially in this film, what would you do to present a more balanced view of Edison the man and inventor? Based on my lecture, discuss why or why not Edison should be considered the creator of the light bulb?
.
Please watch the clip from the movie The Break Up. Then reflect w.docxDIPESH30
Please watch the clip from the movie "The Break Up." Then reflect who you think is most at fault and why.
Then I would you like to think about a conflict you have had and think about what could have been done differently to resolve it.
Write a one page paper (double spaced)
https://www.youtube.com/watch?v=_bqhVqTuFO4
.
please write a report on Social Media and ERP SystemReport should.docxDIPESH30
please write a report on Social Media and ERP System:
Report should be a detail study on social media, effects of social media on business.Use of ERP Systems in social media and its benefits.During presentatio the students should present the use of ERP Systems in the social media aspect.
pages: 15
font size: 11
spaces: 1.5
please see attached file
due date tomorrow, within 24 hour
.
Please write 200 wordsHow has the healthcare delivery system chang.docxDIPESH30
Please write 200 words
How has the healthcare delivery system changed?
For what types of patients and what types of care does each of the systems deliver? Would a patient have a need for more than one system? When (give examples and explain)?
What are the regulations related to the medical staff? What purpose do these regulations serve?
.
Please view the documentary on Typhoid Mary at httpswww..docxDIPESH30
Please view the documentary on Typhoid Mary at:
https
://
www
.
youtube
.com/watch?v=
Mc
8O9
EnAuLo
And read:
- Priscilla Wald, “Cultures and Carriers: "Typhoid Mary" and the Science of Social Control,”
Social Text
, No. 52/53,
Queer
Transexions
of Race, Nation, and Gender
(Autumn - Winter, 1997), pp. 181-214; Available in the Readings Folder and on JSTOR at:
http
://
www
.
jstor
.
org
/stable/466739
Then discuss:
Wald discusses how the concept of "social control" relates or is exemplified by the Mary
Mallon
ca
se
. Choose one of the aspects of Wald's argument and discuss how it relates to the Typhoid Mary documentary. Do these help us understand the significance the 'Typhoid Mary' case has for the history of medicine, or for the treatment of epidemics today?
.
Please use the two attachments posted to complete work. Detailed in.docxDIPESH30
This document provides instructions and deadlines for two assignments. A discussion is due on December 11th by noon and a paper is due on December 13th by noon. It also lists additional research sources that can be used for part two of the assignment, including journal articles and books on business regulation and international trade theory.
Please use the sources in the outline (see photos)The research.docxDIPESH30
Please use the sources in the outline (see photos)
The research essay is to be 12 pages, typed, double-spaced. 10-12 sources are to be used. It is to be on a social policy area and may focus on Canada, or Canada in comparative perspective.
1.
Discuss the National Child Benefit, introduced in 1997. Has this measure been effective in reducing child poverty? Can this measure be seen as the further extension of neoliberalism, or as a new form of state-provided social investment?
Please make a clear and wordy thesis (highlight this in red) use notions of this thesis throughout the paper please. Clear and concise english as this is a university level paper.
Please include your own ideas as well as recommendations.
if a point is made please provide proof with the sources or readings
Please use APA FORMAT.
Please ensure that the paper follows the format suggested in the outline.
.
Please submit a minimum of five (5) detailed and discussion-provokin.docxDIPESH30
Please submit a minimum of five (5) detailed and discussion-provoking questions based on the recent reading assignments, video clips and the other websites assigned.
Only complete questions will earn credit. Therefore, it is important for you to think carefully about formulating the kinds of questions intended to stimulate conversations. Ask detailed and specific, rather than broad, general questions. Do not ask, for example, ‘When was the first Mission established in California?’ Instead, ask something like ‘What is the ideological agenda behind maintaining figures like Father Junipero Serra as heroic in California textbooks?’
Other examples include:
Does recent news media coverage of the “riots” in Baltimore, Ferguson and other cities promote a message that is pro-police? If not, how does it engender understanding of the root causes of many of the frustrations of local residents?
In the film “Banned in Arizona,” why does Superintendent Tom Horne argue in favor of “individualism” and why does he say that the Mexican American Studies program encourages radical thinking? What, if anything, is radical about the way those courses teach students in Tucson, Arizona?
If the U.S. reinstated a Vietnam War era-like military draft instead of relying upon the current all-volunteer force, would current public support for war change at all? If so, how?
Please consider these guidelines in composing your questions:
1. Make certain to ask at least one question from each source.
2. Ask questions about things that interest you.
3. Write your questions as though you were asking them to the entire class.
4. Be sure to make specific reference to the readings in each question. Many good questions require at least two sentences.
5. Try and use the questions to critique the author's opinion.
6. These homework questions should attempt to raise larger issues and---when possible---to relate the readings to issues in our current world.
"This week, I want us to think about the concept of
bias
, and its application in the places we consume information. This is tricky territory because even the very presentation of this unit is fraught with bias—my personal bias, or frame of reference. I’m going to ask you to read a collection of articles that I think are important, but they all clearly have a perspective and an agenda that comes from a particular worldview. So let’s get that out in the open. Maybe nothing in your liberal arts education is free from bias, but that does not mean we shy away from considering the information, ideas, arguments and critiques.
What is bias? For the purposes of our consideration, bias is really just about a set of values that can color or distort fair judgment. We can sometimes recognize obvious bias in others, especially when people use overtly discriminatory or offensive language, or have a clear political or ideological perspective that makes everything they present go through that lens. But more than anything else, I want us to think a.
Please think about the various learning activities you engaged in du.docxDIPESH30
Please think about the various learning activities you engaged in during this unit.
write one page summarizing the following:
Multiculturalism plays an important role in many schools today.
How can this be incorporated into everyday lessons related to health, safety, and nutrition?
How has your school (or your children’s school) incorporated multiculturalism into their lesson?
.
Please type out the question and answer it underneath. Each question.docxDIPESH30
Please type out the question and answer it underneath. Each question should be about a page long DOUBLE SPACED and cited.
Please use the articles that I PROVIDE!
Due date is this Sunday the 14th.
First two articles answer the questions 1 & 2 , the last article answers question 3
PLEASE FOLLOW INSTRUCTIONS
.
Please use the following technique-Outline the legal issues t.docxDIPESH30
Please use the following technique:
-
Outline the legal issues that you are going to discuss in your answer
-
Define the legal rules that are relevant to the question
-
Apply the legal rules to the facts of the question
-
Formulate a decision of which party should be successful
The use of headings for each relationship discussed is suggested.
Application of legal principles to the facts is the most important and often the hardest step. I am more interested in how you arrived at your answer, than the actual conclusions that you draw. Having said that, the “kitchen sink approach” is not suggested – i.e. spilling all of your knowledge that is vaguely related to the issue raised into your answer.
Please do not simply say, “Andrew is liable for negligence.” You must go through the analysis for why or why not a particular tort claim will be successful.
Use the language of the question.
Be as comprehensive and thorough as possible when responding to each issue – canvas all possible answers. If you have considered the application of a particular contractual concept, but after analysis, you have decided that it is not applicable, please go through your analysis.
If any possible remedies are available to either party, please identify with supporting reasons.
Assume for each relationship that the matter is being litigated in court,
not
through alternative dispute resolution.
DUE: TUESDAY MARCH 24
th
, 2015 at beginning of class
No midterms will be accepted after this date.
Tort Law Problem
Andrew Black is the owner of Confederation Mall (“Mall”) located in New Minas, Nova Scotia. Mr. Black leases out many retail spaces in the Mall to a wide range of businesses. He prides himself as a local success story. The people of New Minas truly admire his entrepreneurial success.
George Orange, owner of Guppy World, a pet fish store, has been a long-time tenant of Confederation Mall. Colin and Darren work for Mr. Orange. Colin was repairing a ceiling fan when he asked Darren to toss him a screwdriver, as Colin was up on a step-ladder at the time. Darren, standing 15 feet away, underhand tosses the screwdriver to Colin. Darren overshoots the toss and the screwdriver shatters a glass fish tank containing a piranha fish. At the same time a customer, Sally, was walking towards the check-out to purchase fish food, when she slipped on the water from the broken tank, fell to the floor and fractured her wrist. She is also bitten on the ankle by the piranha. When Mr. Orange tried to assist Sally, he smelled a strong smell of alcoholic beverage coming from her mouth. Colin noted that Sally appeared to be staggering slightly before falling.
Sally was transported to the hospital by paramedics. The doctor determines that Sally’s foot needs to be amputated due to the piranha bite and she needs to wear a cast on her wrist for 6-8 weeks due to the fracture.
Word of the piranha bite spreads like wild fire throughout the Mall. Evelyn, who suff.
Please use from these stratagies This homework will be to copyies .docxDIPESH30
This homework assignment involves using different educational strategies to complete copies of student work. Some suggested strategies include revising and reading, quick writes, learning logs, data charts, and authors chair.
PLEASE THOROUGHLY ANSWER THE FOLLOWING FIVE QUESTIONS BELOW IN.docxDIPESH30
PLEASE THOROUGHLY ANSWER THE FOLLOWING
FIVE
QUESTIONS BELOW IN A 500 Word Count Discussion
Contrast the dynamics between dominant cultures and subcultures either in a work setting or in society.
Explain why it is important to understand the impact of culture.
Give an example where you demonstrated your awareness and or openness to understanding a cultural difference.
Explain how these differences underscore the need for understanding diversity.
From the information given, develop guidelines for embracing diversity.
YOU MUST USE ONE CITED SCHOLARLY SOURCE. PROPERLY CITED IN APA FORM WITH AN REFERENCE PAGE ON THE BOTTOM. DO NOT USE WIKIPEDIA, THESAURUS, OR ENCYCLOPEDIA (THESE ARE NOT CITED SCHOLARLY SOURCES)
DO NOT TURN IN A PLAGIARIZED PAPER, WE WILL REPORT YOU.....
THIS PAPER IS DUE TODAY 12/11/2014.... 8 HOURS FROM NOW MAX NO LATER....SERIOUS INQUIRIES ONLY...DO NOT TAKE THIS PAPER IF YOU DO NOT KNOW THE TOPIC.....
.
Please share your thoughts about how well your employer, military .docxDIPESH30
Please share your thoughts about how well your employer, military base, or home responds to environmental concerns. Provide examples of some types.
1.
Issue 4
-
Re-Wilding
a. Explain what re-wilding is and how it became an issue.
b. Outline and discuss three main areas of disagreement between Josh Donlan and Rubenstein et al.
c. Which side do you agree with? Explain your answer.
Your response should be at least 200 words in length. All sources used, must be referenced; paraphrased and quoted material must have accompanying citations.
Put citation under each answer please
1.
Issue 5
-
Military Training and the Environment
a. Explain the history of military training and the environment.
b. Outline and discuss three main areas of disagreement between Benedict Cohen and Jamie Clark.
c. Which side do you agree with? Explain your answer.
Your response should be at least 200 words in length.
All sources used, must be referenced; paraphrased and quoted material must have accompanying citations.
Put citation under each answer please
1.
Issue 6
-
Carbon Emission Restrictions
a. Explain the history of carbon emissions and why the debate over carbon emissions exists.
b. Outline and discuss three main areas of disagreement between Paul Cicio and Eileen Claussen.
c. Which side do you agree with? Explain your answer.
Your response should be at least 200 words in length. All sources used, must be referenced; paraphrased and quoted material must have accompanying citations.
Put citation under each answer please
1.
Explain in your own words the Section 2017 initiative which Jamie Clark describes on. Then describe how you think Benedict Cohen would respond to Jamie Clark's presentation of Section 2017. Your response should be at least 200 words in length. as source material for your response. All sources used, must be referenced; paraphrased and quoted material must have accompanying citations.
Put citation under each answer please
Explain carbon trading, carbon offsets, and cap and trade. How are each similar? How are each different? Your response should be at least 200 words in length. as source material for your response. All sources used, , must be referenced; paraphrased and quoted material must have accompanying citations.
Put citation under each answer please
.
Please select and answer one of the following topics in a well-org.docxDIPESH30
Please select and answer one of the following topics in a well-organized and thoughtful paper (a minimum of 10 pages in
length). Your paper must contain at least five references in addition to the text. CSU requires that students use the APA
style for papers and projects. Therefore, the APA rules for formatting, quoting, paraphrasing, citing, and listing of sources
are to be followed.
1. If your employer's EMS is registered to ISO 14000, review the registration process. What were the most
difficult implementation activities? How long did it take? How easy was it to get worker buy-in and
participation? Cost? Others.
.
Please see the attachment for the actual work that is require. This.docxDIPESH30
Please see the attachment for the actual work that is require. This will be due on Sunday Nov 9, 2014.
THIS ISTHE CASE STUDY ATTACHED IS THE DIRECTIONS ON OW TO COMPLETE THE TASK.
Case Study Analysis
When it comes to planning events how many of us take the proper steps and put in the time and how many of us wait till the last minute to plan our event? What's the outcome of an event that has had the proper planning? Usually, a properly planned event is a huge success, and people leave-taking away information that will help them either improve, grow as a person or be successful at their job. People who try to plan events without taking the proper steps find themselves running into many problems along the way. Before they know it, they are out of time to fix any issues or problems that arise. Running out of time can lead to frustration, panic, and eventually the thought of “what am I going to do". Even though the steps to planning an event can be time-consuming, proper planning can ease frustration and anxiety, and lead to a successful event. Proper planning can eliminate the “What am I going to do” question.
Background
In the case study, Carl Robins did not plan for his event very well. He hired 15 new trainees and wanted to schedule a new hire orientation on June 15
th
. His goal was to have the new hires working by July. Carl had only been at his job for six months, and this was his first recruitment effort, so it is crucial for this event to work in Carl’s favor. Carl was contacted by Monica Carrolls, the soon to be Supervisor of the new hires, on May 15
th
. Monica was following up with Carl on how the planning for his orientation was going. She asked him about physicals, drug tests, the training schedule, orientation, manuals, and policy booklets. Carl told Monica that everything would be fine and ready to go in time for orientation. After Memorial Day, Carl finally decided to start planning for his event. Unfortunately; because Carl did not do any planning after hiring the fifteen new trainees and waited till the last minute to plan his event, he ran into multiple problems. When Carl finally decided to start planning for his event, he found that the training room where he was going to hold his orientation was booked for the whole month of June by a fellow associate named Joe. Joe was from technology services and needed the room for computer terminals. When he went to finalize the paperwork for his event, he found that some of the new hire trainees did not have completed transcripts or applications on file; nor had they gone to the clinic for their physicals and mandatory drug screenings. He then checked the orientation manuals and found that there were only three and that those three had missing pages. By now, Carl is very concerned, his anxiety is at a level high, and he is so frustrated that he sits with his head on his desk with the thought of “What am I going to do”.
Alternatives
At this point, Carl can .
Please see the attachment and look over the LOOK HERE FIRST file b.docxDIPESH30
Please see the attachment and look over the "LOOK HERE FIRST" file before handshaking to make sure you're committed to the assignment. Everything you need is within the zip folder attached. Thanks in advance. I had someone working on this and then they stopped answering me. Please don't be that person.
.
Elevate Your Nonprofit's Online Presence_ A Guide to Effective SEO Strategies...TechSoup
Whether you're new to SEO or looking to refine your existing strategies, this webinar will provide you with actionable insights and practical tips to elevate your nonprofit's online presence.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
This presentation was provided by Racquel Jemison, Ph.D., Christina MacLaughlin, Ph.D., and Paulomi Majumder. Ph.D., all of the American Chemical Society, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
🔥🔥🔥🔥🔥🔥🔥🔥🔥
إضغ بين إيديكم من أقوى الملازم التي صممتها
ملزمة تشريح الجهاز الهيكلي (نظري 3)
💀💀💀💀💀💀💀💀💀💀
تتميز هذهِ الملزمة بعِدة مُميزات :
1- مُترجمة ترجمة تُناسب جميع المستويات
2- تحتوي على 78 رسم توضيحي لكل كلمة موجودة بالملزمة (لكل كلمة !!!!)
#فهم_ماكو_درخ
3- دقة الكتابة والصور عالية جداً جداً جداً
4- هُنالك بعض المعلومات تم توضيحها بشكل تفصيلي جداً (تُعتبر لدى الطالب أو الطالبة بإنها معلومات مُبهمة ومع ذلك تم توضيح هذهِ المعلومات المُبهمة بشكل تفصيلي جداً
5- الملزمة تشرح نفسها ب نفسها بس تكلك تعال اقراني
6- تحتوي الملزمة في اول سلايد على خارطة تتضمن جميع تفرُعات معلومات الجهاز الهيكلي المذكورة في هذهِ الملزمة
واخيراً هذهِ الملزمة حلالٌ عليكم وإتمنى منكم إن تدعولي بالخير والصحة والعافية فقط
كل التوفيق زملائي وزميلاتي ، زميلكم محمد الذهبي 💊💊
🔥🔥🔥🔥🔥🔥🔥🔥🔥
How Barcodes Can Be Leveraged Within Odoo 17Celine George
In this presentation, we will explore how barcodes can be leveraged within Odoo 17 to streamline our manufacturing processes. We will cover the configuration steps, how to utilize barcodes in different manufacturing scenarios, and the overall benefits of implementing this technology.
Level 3 NCEA - NZ: A Nation In the Making 1872 - 1900 SML.pptHenry Hollis
The History of NZ 1870-1900.
Making of a Nation.
From the NZ Wars to Liberals,
Richard Seddon, George Grey,
Social Laboratory, New Zealand,
Confiscations, Kotahitanga, Kingitanga, Parliament, Suffrage, Repudiation, Economic Change, Agriculture, Gold Mining, Timber, Flax, Sheep, Dairying,
Level 3 NCEA - NZ: A Nation In the Making 1872 - 1900 SML.ppt
LDR-experimentation.pdfpg. 1 COVENTRY UNIVERSITY .docx
1. LDR-experimentation.pdf
pg. 1
COVENTRY UNIVERSITY
Faculty Of Engineering & Computing
AAEE
Light Depended Resistors (LDRs)
Introduction
The light dependent resistor, LDR, is known by many other
names such as photoresistor,
photoconductor, photoconductive cell, or simply the photocell.
These devices were discovered by an
English electrical engineer Willoughby Smith back in 1873.
Smith’s main line of work in 1848 was the
laying of underwater telegraph cables. He developed a method
of testing an underwater cable as it
was being laid. One of the insulation materials used for the
cable was selenium. Upon investigation
of the properties of the selenium insulator he discovered that
the conductivity properties of the
material were affected by light. He published his findings in
1873.
Since then many variants of photoconductive devices have been
made. Other LDRs have been made
using materials including cadmium sulphide, lead sulphide, and
the more commonly used
2. semiconductor materials including germanium, silicon and
gallium arsenide.
The most popular material used in making LDRs is cadmium
sulphide (CdS).
The LDR finds many uses as a low cost photo sensitive element
and was used for many years in
photographic light meters as well as in other applications such
as lighting controls for street lamps
etc.
Basic structure of an LDR
There are many ways in which light dependent resistors can be
manufactured. Essentially the LDR
consists of a resistive material sensitive to light. The photo
resistive element comprises section of the
material with contacts at either end. Although many of the
materials used for light dependent
resistors are semiconductors, when used as a photo resistor,
they are used only as a resistive and
they are purely passive.
A typical structure for a light dependent or photo resistor uses
an active semiconductor layer that is
deposited on an insulating substrate. The semiconductor is
normally lightly doped to enable it to have
the required level of conductivity. Contacts are then placed
either side of the exposed area.
Fig 1 (a,b,c) Close-Up of an LDR (a) Cadmium
sulphate (b) and LDR symbol (c)
(a)
(b)
3. (c)
pg. 2
In many instances the area between the contacts is in the form
of a zig zag, or interdigital pattern.
This maximises the exposed area and by keeping the distance
between the contacts small it enhances
the gain (see Fig.1 (a).
Although other devices such as photodiodes or photo-
transistors can also be used for light sensing
applications, LDRs are a particularly convenient electronic
component to use. They provide large
change in resistance for changes in light level. They are of
comparatively speaking of a lower cost as
compared to other light responding devices.
How an LDR works
It is relatively easy to understand the basics of how an LDR
works without delving into complicated
explanations. It is first necessary to understand that an
electrical current consists of the movement of
electrons within a material. Good conductors have a large
number of free electrons that can drift in a
given direction under the action of a potential difference.
Insulators with a high resistance have very
few free electrons, and therefore it is hard to make the them
move and hence a current to flow.
An LDR or is made from a semiconductor material with a high
resistance. It has a high resistance
4. because there are very few electrons that are free and able to
move - the vast majority of the
electrons are locked into the crystal lattice and unable to move.
Therefore in this state there is a high
LDR resistance.
As light falls on the semiconductor, the light photons are
absorbed by the semiconductor lattice and
some of their energy is transferred to the electrons. This gives
some of them sufficient energy to
break free from the crystal lattice so that they can then conduct
electricity. This results in a lowering
of the resistance of the semiconductor and hence the overall
LDR resistance.
The process is progressive, and as more light shines on the LDR
semiconductor, so more electrons
are released to conduct electricity and the resistance falls
further.
LDR summary
LDRs are very useful components that can be used for a variety
of light sensing applications. As the
LDR resistance varies over such a wide range, they are
particularly useful. In order to utilise these
components, it is necessary to know how an LDR works, can
how it could be used as a light sensing
element that could be used for the control of our robotic
vehicle.
Experimentation
In the experimentation that follows we will examine two
different types of LDRs and we will carry out
some measurements that will help to evaluate the operational
parameters and uses of LDRs. Some of
5. the experimentation will involve the interfacing of the device to
our PIC18 microcontroller and
associated peripherals using both Digital and Analogue I/O
interfacing methods.
pg. 3
Apparatus
LDR modules (2 different types supplied)
Torch
5 volt fixed PSU and connecting leads
Digital multimeter (for voltage and resistance measurement)
Breadboard
10k ¼ resistor
Other resistors to be selected by user calculations
Light meter (if available)
For the PIC interface part of the laboratory you will ALSO need
the following:
PC with MPLAB V5.6 or higher and USB port
ICD 3 and USB lead
6. PIC18F4520 Target board
ADC Potentiometers board and IDC10 way connecting cable
PIC18 Prototyping board and 10way ICD connector, 2-way
connecting lead for Port B
10-LED Bargraph display
3 x 270R resistors
Extra LED
Connecting wire links
Task 1 Identifying the resistance variation Versus incident
light
Connect an Ohmmeter across the terminals of one of your
supplied LDR devices. (See diagram Fig.3)
Take a range of measurements of device resistance versus
incident light. Ideally you will need a light
meter for this task. If this is not available use ambient light
readings, as well as a variety of other
readings i.e. fully covering up your device with your finger or
other means and by using your torch to
shine a light on your LDR at from various distances.
Repeat the exercise for the second type of LDR supplied.
Discuss your findings and compare the results/readings from the
two devices.
Compare your results with the data sheet of one of your devices
as supplied in the Appendix.
Fig.3 System setup for Task 1
Fig.2
7. Light meter
pg. 4
Task 2 LDR in a voltage divider arrangement
In Task 1 we investigated the resistive response of the LDRs in
a stand-alone arrangement
examining the resistive changes of the device in response to the
incident light on the device.
In Task 2 will examine the use of an LDR in a Potential Divider
circuit arrangement and investigate its
use in a real light sensing situation when a voltage change
across it, or across the associated part of
the circuit can be used to measure/control an application in
mind.
For this exercise we will connect one of the LDRs to the circuit
configuration shown below in Fig 4 (a
and b). From the previous results from Task1 choose the LDR
that you think is best suited for this.
Resistor Rx has an initial value of 10K. The value of Rx will be
changed later on after you
have identified the operation parameters of the circuits.
Fig. 4 (a and b) Circuit diagram connection for task 2
Procedure
You are going to investigate the behaviour of these two circuits.
Later on you will also need to find
out how to choose a sensible value for resistor Rx in the voltage
8. divider circuit.
Connect the circuit shown in Fig.4 (a). Note that your Vcc
supply voltage is set to +5volt.
Start with a fixed Rx value of 10k . Connect this to the bottom
part of your voltage divider circuit.
Connect a voltmeter across your Rx (10K) resistor. Take a
number of readings of your Vout under a
varying light illumination condition. Create a table and enter
measured voltage values.
The formula for calculating Vout is as follows:
Change Rx to a 5k value take similar measurements as before
and place them in another table.
Compare the two tables, comment on your findings and verify
the above equation.
Repeat the above exercise by swapping the Rx and LDR
positions as shown in Fig.4 (b).
(a) (b)
pg. 5
Considering that our Robotic Vehicle will be using LDRs for
light direction control choose the
appropriate Rx value by calculations and experimentation so
that the LDR provides the appropriate
voltage output level for a recognised logic 1 (between 2.5 and 5
volt) when illuminated at an
accepted distance from the sensor without any interference from
9. ambient light changes/fluctuations
and a logic level 0 (between 0 and 0.7 volts) when LDR is not
illuminated.
Remember that in this instance we will be using two discrete
light levels of Illumination / NO
Illumination that will relate to corresponding logic levels of 1
and 0 that could be recognised by a
digital input Port pin of the micro (use PortC).
Further experimentation
1. In the further experimentation that will follow you will need
to focus upon the interfacing
methods in connecting the potential divider’s output (LDR/Rx
arrangement) to the PIC18
micro’s configured Input Port C0 pin that will sense and
respond to incident light by an
illuminating/flashing an LED on the same Port that has been
configured as output. You will
need to decide upon the potential divider configuration and the
appropriate Rx value
calculated/chosen.
2. For the second part to this LDR/PIC18 interfacing study you
will need to refer back to your
previous ADC experimentation.
Connect the voltage divider’s Vout to the AN0 pin (channel 0)
of Port A as shown in Fig. 5.
Convert the Light dependant varying analogue input to your
ADC and display its digital
representation on output Ports D and B as we have seen in the
10. previous ADC experimentation.
Decide upon the acceptable light threshold levels and flash an
output LED on an output pin of
PortC0.
P. Abatis Doc/LDR V2.0
http://web1.eng.coventry.ac.uk/Panos/Info/Experiments/Micros/
202CDE/LDR%20experimentation.pdf
Fig. 5
Connecting the LDR to
the PIC18 ADC
http://web1.eng.coventry.ac.uk/Panos/Info/Experiments/Micros/
202CDE/LDR%20experimentation.pdf
pg. 6
APPENDIX
pg. 7
11. Light Depended Resistors (LDRs)Basic structure of an LDRHow
an LDR worksLDR summary
lab-details.docx
102SE Activity Led Learning Project
Introduction
In this project we will apply our previous experimental work of
the PIC in connection with the earlier work we undertook on the
light dependent resistor plus we will use the programming
experience and experimental activity to:
1. Develop and refine a project specification
2. Work together as members of a team to undertake a specific
task
3. Design and implement a prototype (sub system component,
system component)
4. Implement test and quality procedures
5. Design suitable container for the cell.
6. Describe a method of communication between the cell and a
central processing unit i.e. a PC.
7. Describea production process, main tasks and processes
together with a schedule of events.
8. Report project outcomes.
Scenario:
You are asked to create part of a prototype light cell that
converts optical pulses into digital electronic pulses in order to
count them. The optical switching rate is very low i.e. pulses
per minute.
Figure 1 Outline of the System
To convert optical pulses into digital pulses there is a need to
12. set up the LDR in conjunction with an electronic module (built
withOPAMPS),the functionality of the LDR setup and electronic
module is shown as per the arrangement shown in figure 2.
Figure 2 Input / Output Characteristic of LDR / Electronic
Module
Report
Each student is required to submit an individual report
(maximum 1500 words). Your report should concentrate on:
1. Design of the LDR and electronic signal conditioner part of
the light cell plus testing 35 %
2. Software Development plus testing 35 %
3. Design of container 10 %
4. Production processes an outline of main processes and
equipment 10%
5. Conclusion 10 %
Submission Date
04/04/14 Moodle 23.55
Important:Very short extracts from published sources may be
included in answers but you should avoid copying significant
amounts of text from other authors. You should note that whilst
the Internet can provide lots of information much of it is not
refereed and should be treated with caution. If you take material
from elsewhere and incorporate it in your answer word-for-
word, you must indicate where you have taken it from. A guide
to academic citation and writing is available at:
http://wwwm.coventry.ac.uk/caw/Pages/CUHarvardreferencestyl
e.asp
RFJ 2013-2014
UNDERGRADUATE RESEARCH PROJECT
Project goal:
Align student career interests with course learning outcomes
(CLOs) as defined in the Course Outline.
13. Students will choose a business manager working in an industry
that interests them and conduct the research below. This will
include two interviews as well as an experiential journal and a 5
page (1500 word) min. reflection paper.
*STUDENT MUST HAVE COMPANY NAME, MANAGER
NAME, WEBSITE, ADDRESS, PHONE NUMBER AND
EMAIL APPROVED BY PROFESSOR HAEGER BEFORE
PROCEEDING IN ORDER TO GET CREDIT FOR THE
ENTIRE PROJECT.
· Please provide the above information and date of first
interview to me in class by the due date above.
· See syllabus above for due dates of each interview transcript
(1) and 5 journal entries (all in one word doc) TO BE
SUBMITTED TO A DROPBOX IN ANGEL. These items
equate to your homework grade for the course. 5+5+5 = 15
points (15% OF YOUR GRADE).
· Final Project PAPER is due as per above syllabus (Also 15%
of your grade).
Problem Definition:
What are managers looking for in a new hire and leader? What
characteristics and competencies are they finding? Do they
match up? How does the manager lead employees?
Studies show that new entrants into the working community
lack expected leadership skills and competencies. This research
is directed toward local businesses to determine what
deficiencies and strengths exist in potential leaders being hired
today. The managers being interviewed can also provide
insights based on the way they choose to lead their employees.
Significance to society/business: New entrants will gain an
understanding of what companies are looking for in a leader.
Businesses will benefit from a richer pool of future applicants.
14. Benefits of the research:
· MCC: insight for student body relative to the work
environment and application of CLO’s to real world.
· Community: Assist students as current workers to become
more effective applicants and leaders.
· Area business: Richer pool of applicants in the future as
students apply what they have learned to their own learning
agenda.
· Researcher: Personal insight into leadership competencies and
skills relative to employer needs.
PROJECT SUMMARY:
A. Student will make contact with a hiring manager.
Student will choose an industry and make contact with a Senior
Manager or Hiring Manager.
The student will meet at least twice with the manager to gather
information. The meetings should be face to face. Student must
offer a copy of their final report to the manager. If you can get
permission it is helpful to record the interview since you will
need to type up a transcript for each.
B. Students will journal personal experiences and thoughts
throughout the project. Five entries are require in ONE word
document submitted to a dropbox in ANGEL. ONE WORD FILE
is accepted. Not five files. You will receive a zero if you
submit five documents.
Experiential Journal:Your journal is about your personal
experience during the project. What are you thinking?
The experiential journal will be five separately DATED entries.
Each entry will be from a different day and express thoughts
regarding a different phase of the project. Entries will be in
15. paragraph form, dated and at least 120 words each. Students
may journal in a free flow manner about the project. The
guidelines below are for students who have not written a journal
before and need a starting point.
· The first entry could be prior to your meetings. Please write
about the company you chose, the manager you will meet with
and a bit about the company itself. Why is this company your
choice?
· The second entry could be prior to your meetings. Please
journal about what you are expecting to find and what you think
you might learn from the experience as well as any other
thoughts you are having.
· The third entry could be after the first meeting. Please journal
about what you personally experienced during your meeting.
Perhaps add what you think will occur at the next meeting.
· The fourth entry could be after the second meeting. Please
journal about what you personally experienced during your
meeting. Add how you feel these meetings will help you with
your paper.
· The fifth entry could be a summary of the entire meeting
experience. Add how you feel this experience will help you in
your life and career.
C. Students will conduct field survey interviews/meetings.
Questions and answers will be typed up and handed in as part of
the project. (transcripts)
Field Interview Protocol:
Students will spend time in class collaborating and developing
rich surveys with which to administer and converse with the
chosen manager.
16. Survey Questions: EXAMPLES
· What knowledge, skills, and abilities is the manager looking
in a leader?
· Does age make a difference when hiring a new leader? Why?
· What are the benefits of having an education when entering
this field?
· Describe the type of person you would most likely place in a
leadership role.
· Is the person above hard to find? Why or why not? What is
missing?
· What can be taught through training?
· In a perfect world describe a new employee whom you would
assign to a leadership role.
· Additional manager comments or insights.
Students are encouraged to add questions as they surface during
the interview to enhance the study. Questions and answers are
typed up in transcript form. Transcripts submitted will be at
least 800 words. Students are encouraged to record the
meetings with permission or take notes.
D. Students will write a synthesis paper at least five pages in
length and a minimum of 1500 words.
Synthesis Paper
Students finalize this project by writing a synthesis paper
relating their field experience and journals to course concepts
and demonstrate the ability to think critically about the
experience by making connections and providing insights about
17. the field. It is suggested that students choose at least four
concepts covered in the course and synthesize them with the
responses from the interviewee. Each connection must conclude
with insights relative to similarities and differences that surface
between the field experience and the course itself. Students are
encouraged to think critically and make suggestions that are
relevant to either improving themselves, the business, or the
leadership. (Students usually see real world examples of what
we are learning in class during this project, however sometimes
they end up in a “what not to do” interview. This is excellent
fodder for a paper on improvements using applicable course
concepts.)
Please relate the significance of this project to your course
work. Select at least four course concepts that surfaced during
your interview. It is a good idea to review the first interview to
identify concepts. If you are low on ideas, the second interview
is a great time to ask more questions!
For Example: If during the interview, the manager talks about
training of employees at length, then this is a good topic for you
to discuss in your paper by connecting it to topics covered in
class and in your text. Share the main idea expressed by the
manager, then refer back to what the course (text, notes) says
about training (i.e., types of training) and then identify what
type the manager may have talked about and give an example of
how the manager carries out this training in the workplace. If
you do this, you have created the synergy intended for this
project!
Format: one inch margins, 11 pts. Double spaced. There should
not be heading except on the cover sheet. Cover sheet will have
your name, my name, the name of the course and the date.
Optional - Rough Drafts are accepted through email if you
would like my feedback up to two weeks before the due date.
18. All parts of this project with be submitted in ANGEL via a
dropbox. A document in WORD format must be attached to the
dropbox. One submission only will be allowed and one file per
dropbox assignment will be accepted.
Earthlink Company
Earthlink Company is a communications network firm based in
Atlanta Georgia. The company serves over one hundred and
fifty businesses worldwide with most of its consumers coming
from the United States. Earthlink operates under two distinct
divisions;EarthLink Consumer Services and Earthlink Business
Services. EarthLink Business Services offers connectivity
services such as the Ethernet, DS3,DSL,T-1, wireless and
MPLS. It also offers wholesale services in the field of network
services and fiber capacity. This company offers services to a
considerably huge population of the United States of America.
EarthLink has a subsidiary in Rochester, NY where they provide
technical support for online and phone services. I had the
opportunity to speak with Tom, the technical special manager
tasked with the responsibility of supervising technicians. He
also handles complains related to technical support.
What knowledge, skills, and abilities is the manager looking for
in a leader?
Tom told me that a leader should help in meeting the
organizational goals. New leaders in EarthLink Company are
expected to delegate duties to the employees in a manner that
will help meet the company’s objectives. Through their strong
career commitment, they should lead by example. With the
constant advancement of technology, leaders should keep up
with innovations by carrying out constant research. Currently,
EarthLink’s biggest challenge is increased competition from
other market players. Therefore, to ensure that their company
remains competitive, leaders must see to it that their company
19. offers the best services. The new leaders must be people who
continuously do research to ensure that the company offers the
best services. Following this, the new leader must encourage
other employees to find any useful information that might lead
to the development of unique services. The leaders must gain
the credibility of the employees and the public in general. A
leader should be in a position to instill confidence among his
employees; this ensures that the employees carry out their
duties without any hesitation. To get a job as a leader in the
EarthLink Company, a person must be very confident in making
decisions. The leader must ensure that they make well informed
decisions that will make the organization more focused on its
goals. As a manager of EarthLink Company, there are set
standards that the leaders must possess in order to qualify.
Through a series of tests, our interview panel will choose the
right person for the leadership position. Additionally, a leader
must possess the ability to make right decisions leading to an
improvement of company performance.
Describe the type of person you would most likely place in a
leadership role.
Apart from being more innovative, they must have motivational
skills. This means that a leader provides the necessary
encouragement to keep employees going. I would choose a
leader who maintains good employee welfare. This is achieved
by providing a good working environment, sufficient
remuneration, strict adherence to work ethics as well as creating
a healthy working environment. Since EarthLink Company
largely engages with young innovative people, the leader must
be very approachable. Another skill that the EarthLink company
leaders should portray is the ability to delegate responsibilities
in their departments. Delegating the duties and responsibilities
in the organization plays a key role in team building. The
employees work as a team and assist each other in income
generating activities. TheEarthLink company has several
20. departments whose success is based on the successful
completion of responsibilities from other departments. For
instance, if the production sector manufactures beverages on
time marketers will be able to carry out their duty as well as the
supplies and logistics. The new leader in Earthlink Company
must have the ability to communicate their responsibilities to
the employees using the right terms. If a leader comes up with
an idea but fails to communicate well to the employees then it
will not be well implemented. The manager needs to pass the
ideas to the employees exactly as it should be implemented so
as to gain the expected results. Earthlink employees should
understand what the leader expects them to do. The leaders
should also learn to accept criticism by listening to the opinions
that their employees have. Leaders also make mistakes and
should be able to accept what their employees do so.
What are the benefits of having an education when entering this
field?
The candidate should have a Bachelor of Science degree. The
education background of a leader is very important since it horn
his/her decision making skills. For example, Earthlink prefers
candidates who have the right educational background which
imparts them with problem solving skills. Anyone intending to
be a leader in this field should be aware of the market
population, company branches, and the firm’s level of
participation in the industry. In addition, they must have a good
grasp of the company’s growth trends and be in a position to
predict its future prospects.
Teacher Comment
This is very interesting! Remember to ask for examples so you
can use them in your paper. I look forward to reading more
about Earthlink!