Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Post: #1

Post: #2
Ultrasonic motion detectors emit and receive ultrasonic sound energy in a region of interest.Object motion within the region of interest and in the range of the ultrasonic motion sensor is detected and an alarm signal is produced.The range of these detectors differs from the designed range whenever the actual atmospheric sound propogation conditions vary from the atmospheric conditions assumed in the design .Ultrasonic motion detectors are commonly used for automatic door openers and security alarms. ultrasonic beams are easily blocked by thin materials, including paper and as a result False triggering is easly caused by reflections from blowing curtains, pets, and flying insects.

Circuit description
The circuit uses a matched pair of 40 kHz transducer elements to detect movement up to 22 feet away. Crystal locked circuit for maximum stability. An LED is switched on for movement indication. The transmitter sends out a steady ultrasonic signal at 40kHz( wavelength ~= 6 mm).
The reflected sound is detected by ultrasonic receiver. The
signal is then amplified by amplifiers.An amplifier is selfbiasing. The time constant of the first amplifier is set to let the 40kHz signal through. Between
the first & second amplifier there is a negative peak
detector consisting two diodes which follows the envelope of
the 40kHz signal. If there is no movement the envelope is
just a straight line. The time constant ofsecond amplifier is much slower so that it will follow this envelope. When
there is no movement neither diodes can conduct. If the signal falls or rises the diodes conducts which the output to go high. A low pass filter screens out unwanted spurious signals. Specific details about the circuit are available in this link:

Important Note..!

If you are not satisfied with above reply ,..Please


So that we will collect data for you and will made reply to the request....OR try below "QUICK REPLY" box to add a reply to this page
Popular Searches: motion analysis seminar topics, ultrasonic algae control, ultrasonic motion detector ppt download, motion sensors, arrythmia detector matlab, ultrasonic movement detector project synopsis, viola jones detector,

Quick Reply
Type your reply to this message here.

Image Verification
Image Verification
(case insensitive)
Please enter the text within the image on the left in to the text box below. This process is used to prevent automated posts.

Possibly Related Threads...
Thread: Author Replies: Views: Last Post
Last Post: Guest
  ultrasonic blind helper [email protected] 2 2,639 13-02-2013 08:33 PM
Last Post: Guest
  wireless speed control of dc motor using fire detector sushree sangeeta mohanty 1 875 21-11-2012 01:14 PM
Last Post: seminar details
  ultrasonic alarm for visually impaired Guest 1 791 19-07-2012 07:25 PM
Last Post: Guest
  mobile detector project ppt 1 845 15-03-2012 11:38 AM
Last Post: seminar paper
Question Alive Human Detector junkyardworker 1 529 09-03-2012 12:45 PM
Last Post: seminar paper
  Accident avoiding system using ultrasonic device MRSARAVANA 1 860 09-03-2012 11:51 AM
Last Post: seminar paper
  Temperature detector and controller using microcontroller 8051 Teju Ghadge 1 1,259 08-03-2012 12:36 PM
Last Post: seminar paper
  mobile phone sniffers/detector/bug akin999 2 1,247 04-03-2012 09:13 AM
Last Post: Guest
  Alive human detector project smit barot 0 382 24-02-2012 02:54 PM
Last Post: smit barot