To make a laser-guided door opener. It can be termed as an automatic door opener as it requires no manual force and works automatically. As the name indicates the door opening operation is done with the help of a laser. The objective of the kit Laser Guided Door Opener is to design a type of door arrangement which can be open using Laser guided torch and can be close using a Microswitch.
In the kit Laser Guided Door Opener the LDR detects the light intensity and generates an analog voltage. This variation is monitored by forming a potential divider circuit. This analog variation is converted into digital form using a dual op-amp IC LM358. The op-amp is used as a comparator in the inverting mode to do so. In this operation, we set a reference voltage with the preset which is connected to pin 5 of IC. If the analog voltage from the sensor is less than Vref than the output is logical high on pin 7 else it is low. The analog input is connected to the pin 6. The output from the LM358 drives the motor driver IC l293D which in turn drives the DC motor to open the door. The output from pin number 2 of LM358 is connected through a switch to the motor driver. As the switch is pressed the signal is fed to the motor driver L293D to drive the motor to close the door.