Engineers Garage

  • Projects and Tutorials
    • Electronic Projects
      • 8051
      • Arduino
      • ARM
      • AVR
      • PIC
      • Raspberry pi
      • STM32
    • Tutorials
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Products News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • Digi-Key Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • EE Resources
    • DesignFast
    • LEAP Awards
    • Oscilloscope Product Finder
    • White Papers
    • Webinars
  • EE Learning Center
    • Design Guides
      • WiFi & the IOT Design Guide
      • Microcontrollers Design Guide
      • State of the Art Inductors Design Guide
  • Women in Engineering

Window and Door Guard with Light Sensor

By Ashutosh Bhatt

The circuit described here can be used as burglar alarm or can be used as an indicator that door or window is open.

Now the summer time is coming and we all are going to use AC in our home and offices. AC functions efficiently, only when doors and windows are closed properly. If any of the door or window is left open then effect of AC cannot be felt. So we have described a circuit here that will give an alarm when door or window is left open.

Another application when you can use this circuit, in your cupboard or lockers. When light fall on the sensor it will give an alarm indicating that somebody is trying to steal your valuable thing. And will also give an alarm when any unwanted person is trying to open door and window. 

[[wysiwyg_imageupload:11701:]]

Fig. 1: Prototype of Window and Door Guard with Light Sensor Circuit on Breadboard 


This circuit is based on 4093 IC, Reed switch and LDR as a sensor with few more components.

 

4093 is a Quad 2 input NAND schmitt triggers IC. It comes in 14 pin Dual inline package. Important feature of IC is when there is no external component schmitt action will be provided to each input pin. It can be used in astable and monostable multivibrator application and in high noise environment system.

NAND gate will give output as high when any of the input logic signal goes low or both the input signal become low. And if both the logic signals applied are high then we will receive low output.

CD4093 contain 4 individual gate in a single IC. In this pin1 and 2 is for input and pin 3 is for output. Similarly pin 5 and 6 is input and pin 4 is for output. In this circuit we are utilizing all four gates of CD4093 IC.

Working of circuit is very simple when all doors and windows are close then pin 1 and 2 of IC1 is at high state therefore out pin 3 will be low, therefore no sound will be heard. As soon as when somebody left the door or window open than capacitor C1 charges through resistor R1 and after some delay input pin 1 and 2 of N1 become low. This will trigger the pin 5 and 6 of N2 and output pin 4 becomes high. Which in turn enable the gate N3 and buzzer starts sounding. In this circuit N4 is used as an inverting buffer. And capacitor C2 and resistor R3 is used to set the astable frequency.

Now when there is no light falls on LDR its resistance is high therefore pin 12 and 13 both are high and pin 11 of N4 is low so no buzzer will sound. But as soon as light falls on LDR its resistance become low and pin 12 of N4 goes low to enable the buzzer. You can set the sensitivity of LDR with the help of variable resistor VR1. If you want to remove this section you can do so by just removing the LDR and replace it with 10K resistor.

If you want to protect more than one door or window then just add more number of switches in parallel with switch S1.

Circuit Diagrams

Window-and-Door-Gaurd

Project Components

  • Capacitor
  • LDR
  • Resistor

Project Video


Filed Under: Electronic Projects
Tagged With: light sensor
 

Questions related to this article?
👉Ask and discuss on EDAboard.com and Electro-Tech-Online.com forums.



Tell Us What You Think!! Cancel reply

You must be logged in to post a comment.

HAVE A QUESTION?

Have a technical question about an article or other engineering questions? Check out our engineering forums EDABoard.com and Electro-Tech-Online.com where you can get those questions asked and answered by your peers!


Featured Tutorials

  • Introduction to Brain Waves & its Types (Part 1/13)
  • Understanding NeuroSky EEG Chip in Detail (Part 2/13)
  • Performing Experiments with Brainwaves (Part 3/13)
  • Amplification of EEG Signal and Interfacing with Arduino (Part 4/13)
  • Controlling Led brightness using Meditation and attention level (Part 5/13)
  • Control Motor’s Speed using Meditation and Attention Level of Brain (Part 6/13)

Stay Up To Date

Newsletter Signup

Sign up and receive our weekly newsletter for latest Tech articles, Electronics Projects, Tutorial series and other insightful tech content.

EE Training Center Classrooms

EE Classrooms

Recent Articles

  • What are the battery-selection criteria for low-power design?
  • Key factors to optimize power consumption in an embedded device
  • EdgeLock A5000 Secure Authenticator
  • How to interface a DS18B20 temperature sensor with MicroPython’s Onewire driver
  • Introduction to Brain Waves & its Types (Part 1/13)

Most Popular

5G 555 timer circuit 8051 ai Arduino atmega16 automotive avr bluetooth dc motor display Electronic Part Electronic Parts Fujitsu ic infineontechnologies integratedcircuit Intel IoT ir lcd led maximintegratedproducts microchip microchiptechnology Microchip Technology microcontroller microcontrollers mosfet motor powermanagement Raspberry Pi remote renesaselectronics renesaselectronicscorporation Research samsung semiconductor sensor software STMicroelectronics switch Technology vishayintertechnology wireless

RSS EDABOARD.com Discussions

  • Slope compensation ramp calculation for UCC38084
  • Parts storage / inventory best practices and organization
  • Unusual gap shape of ETD59 ferrite core?
  • Vco cadencd
  • WH-LTE-7S1 GSM module and SIM card problem

RSS Electro-Tech-Online.com Discussions

  • HV Diodes
  • intro to PI
  • surge arresters
  • NOR gate oscillator in LTspice not working
  • Very logical explanation on low calue C3
Engineers Garage
  • Analog IC TIps
  • Connector Tips
  • DesignFast
  • EDABoard Forums
  • EE World Online
  • Electro-Tech-Online Forums
  • Microcontroller Tips
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips
  • 5G Technology World
  • About Us
  • Contact Us
  • Advertise

Copyright © 2022 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy | Advertising | About Us

Search Engineers Garage

  • Projects and Tutorials
    • Electronic Projects
      • 8051
      • Arduino
      • ARM
      • AVR
      • PIC
      • Raspberry pi
      • STM32
    • Tutorials
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Products News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • Digi-Key Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • EE Resources
    • DesignFast
    • LEAP Awards
    • Oscilloscope Product Finder
    • White Papers
    • Webinars
  • EE Learning Center
    • Design Guides
      • WiFi & the IOT Design Guide
      • Microcontrollers Design Guide
      • State of the Art Inductors Design Guide
  • Women in Engineering