IR Motion Detector alarm

This type of motion detector uses the same basic concept as the active infrared motion detector. An interruption in a 5 kHz modulated pulsating beam that is transmitted by an infrared diode and received by an infrared transistor sets off the alarm.

IR Motion Detector alarm - img1

For our project, we decided to construct an active infrared motion detector. Originally, we wanted to build both an IR and an ultrasonic detector, but we decided that an ultrasonic detector would require too much time for a three week project. The circuit on the left is the transmitter circuit that establishes a 5 kHz modulated infrared beam. As you can see from the schematic of the receiver circuit, a resonance-tuned narrowband amplifier reduces the detector`s sensitivity to stray light. C1 and L1 in IC2A`s feedback loop cause the op amp to pass only those frequencies at or near the LED`s 5 kHz modulation rate. IC2B`s output increases when the received signal is sufficient to drop the negative voltage across C2 below the reference set by R2. The output of this circuit is then attached to some load resistance, which can be an alarm or, for demonstration purposes, an LED. However, we also decided that just building an IR motion detector would probably be a trivial exercise. So, we decided to expand on the concept by building an ambient light ignoring motion detector.


Recommended videos

  • How to make a Motion Detection Alarm using PIR Sensor
    Duration: 8:12.
  • Laser Light Security Alarm Circuit
    Duration: 0:45.
  • How to make an infrared Entry


    KRCRTV.COM at dispensariesSome of the safety protocols include color cameras in all rooms of dispensaries, along with burglary and fire systems. Outdoor commercial cultivation will not be allowed, and employees would need to wear ident
     28 April 2017
  • Security Sales & Integration
    Security Sales & Integration This was follow-up to a Vision 20/20 workshop on smoke that I attended and reported on in 2015. Further back on the topic, CPSC had conducted a national survey in 1992 on the functionality of smoke . The prin
     27 April 2017
  • RT
    RT BeijingThe probe will also look into possible lost jobs, skills, and investment in national , Ross said. Wilbur Ross said production in the US is now down to the level of 1952, and the country imports 55 percent of its needs, the high
     27 April 2017
  • police
    BBC News
    BBC News robot attacked by drunk man - police on the 5ft (150cm) tall robot, which is known as K5, sounded after it was knocked down, said Knightscope. A company employee went outside to stall the man until Mountain View police could arr
     26 April 2017
  • signs prevent eak-ins?You've probably walked past your neighbor's yard and wondered if those fake security signs they're sporting actually work as deterrents. Can you just slap a home company's sticker on your window and keep po
     26 April 2017
    KABC-TV The video shows two men knocking at the door of the home in the 14000 block of Davana Terrace on April 7. When no one answers, the walk into the backyard, smash the glass back door and ransack the home as the blare. They made off wit
     26 April 2017
  • Tips For Vacation Homes & Extended TravelNeighbors, and notifying your local police department that you will be gone still remain the best way to keep your home safe. Get free real-time news alerts from the Newport Beach-C
     25 April 2017
  • Security Sales & Integration
    The city adopted enhanced call verification (ECV), plus sharply reduced permit fees for alarm systems and hiked fines for false alarms.
     14 April 2017
  • Bravo (blog)
    Bravo (blog) In Stores?If you didn't steal anything and the goes off, that means you're carrying or wearing an item with a tag that somehow didn't get deactivated by a cashier. Anti-theft systems have been around for decades, and can o
     13 April 2017