Latest Simple LDR Projects for Engineering Students

The term LDR is known by many names such as a light-dependent resistor, photoresistor, photoconductor, the photocell. The term photocell is most widely used in datasheets as well as instruction sheets for domestic gear. The light-dependent resistor is a low-cost photosensitive element and was used in photographic light meters as well as in various applications like flame detectors, card readers smoke detectors, burglar detectors, and lighting control in street lamps. This article discusses bout LDR projects for engineering students.

LDR Projects

Project work for students helps to enhance technical skills in engineering. There are various branches in which students can develop the projects. In our daily life, we may observe various sensors based projects such as LDR based automatic lighting system at outdoors, Ultrasonic sensor-based automatic water tank system, PIR sensor-based automatic door system, heat sens

-]or based automatic cooler or fan or air conditioning system, and so on. Here a few innovative LDR sensor-based projects for engineering students with a brief description are discussed below.

Security System Controlled by an Electronic Eye

The main aim of this project is to design a security system controlled by an electronic eye. This project uses a photo-sensing arrangement so, it uses a 14 stage ripple carry binary counter to detect the intensity of light using a light-dependent resistor. The o/p of the LDR makes a relay to give an alert for necessary action. This project mainly uses an LDR sensor.

When the light falls on the LDR, its resistance extremely falls which leads to activating an alarm to the user. This project is suitable for providing a friendly security system for lockers, cash boxes which can be found where security is required like banks, shopping malls, jeweler shops.

The circuit of this security system is placed in the locker or cash box in such a way that, when the burglar unlocks the locker and using a torch it finds the valuable things. When the light drops on the LDR then it gives an indication to the ripple counter.

The circuit is placed inside the cash box in such a way that, when the burglar opens the locker and uses a torchlight to find the valuables, the light falls on the circuit which contains an electronic eye (LDR) and gives a signal to the ripple counter. This activates the alarm and specifies a robbery attempt. Here, a lamp is used to specify the theft when the light drops on the light-dependent resistor.

Furthermore, this project can be developed by using GSM technology and 8051 microcontrollers. In case of robbery, a GSM modem can be connected to the microcontroller to send an SMS to the operator.

Dusk to Dawn Lighting Switch

The dusk to dawn lighting switch project is used where the light will continue on only from sunrise to sunset (dusk to dawn).

Nowadays, the electricity cost is very high and it is advisable to use electricity carefully. The applications of this project mainly include where more electricity is required in the night time like highways, complexes, colleges, parks, and industries. The proposed system gives a solution for these applications and automatically the lights will be on at sunset and turn off at sunrise. So, conserving money, energy, human interference is also excluded.

This project uses an LDR which senses the change in light intensity and also o/p changes accordingly. The o/p of the light-dependent resistor is fed to an IC 555 timer in astable mode, which turns on the light during sunset and turns off during sunrise. Here 555 timer is used to control the load using a TRIAC

Time Programmed Sun Tracking Solar Panel

This project uses a solar panel which is fixed to a stepper motor to track the sun so that full sunlight is made incident upon the solar panel at any time of the day. This is best compared to the light detecting method that may not always be correct.

The solar panel is used to convert solar energy to electrical energy is very famous, but due to the moving of the sun from east to west, the solar panel may not be able to produce ideal energy. To overcome this problem, this project is implemented to track the sun using a solar panel.

The movement of the solar panel is done by connecting a stepper motor so that the panel keeps its face always vertical to the sun to produce maximum energy. This is attained by using a pre-programmed microcontroller to send stepped pulses in periodical time breaks for 12 hours for the motor to switch the mounted panel. Here solar panel rotates in one direction & then comes back to the start point.

This project uses an 8051 family microcontroller and the motor is motivated by an interfacing an integrated circuit as the microcontroller is not capable of controlling the requirements of the power of the motor. Furthermore, this project can be developed by using a real-time clock to track the sun. This helps in keeping the necessary position of the solar panel even if the power is disturbed for some time.

Security Alarm System by Photo Electric Sensor

This project is used to avoid robberies in public areas like banks, jewelry shops, malls, etc. This project uses a photo-sensing arrangement and light depending sensor that detects the intensity of light and produces an alarm for representing robbery and also turns on the lights.

When light falls on the LDR, its resistance extremely decreases, which leads to causing an alarm to alert the operator. This project is suitable for providing security for public areas. The circuit of this security system is placed in the locker or cash box in such a way that, when the burglar unlocks the locker and using a torch it finds the valuable things. When the light drops on the LDR then it gives an indication to the ripple counter.

Furthermore, this project can be developed by using a GSM technology and also a microcontroller. In case of robbery, a GSM modem can be connected to the microcontroller to send an SMS to the operator.

This is all about LDR projects which include Furthermore, any technical help regarding this topic or electrical and new electronics project ideas, you can feel free to give feedback by posting your queries in the comments section below. Here is a question for you, what are the applications of the LDR sensor?