Ultrasonic and Infrasonic Devices

Electronics Infoline Web

Ultrasonic Range Finder EDN

http://www.web-ee.com/Schematics/Ultrasonic Range Finder/Ultrasonic.htm

http://circuitos.tripod.cl/schem/r72.gif

http://www.web-ee.com/Schematics/Ultrasonic%20Range%20Finder/Ultrasonic.htm

http://www.geocities.com/robobix/US.html

http://www.web-ee.com/Schematics/Ultrasonic%20Range%20Finder%20II/UltrasonicRangefinderII.htm

with alarm system

http://www.4qdtec.com/ultra.html

http://www.web-ee.com/Schematics/Ultrasonic Range Finder II/UltrasonicRangefinderII.htm

An ultrasonic sonar that shows distances from obstacles with both a LED bar graph display and an alarm buzzer.

http://www.riccibitti.com/sonar.htm