Ultrasonic Proximity detector

Ultrasonic Proximity detector - CIRCUIT IDEAS ULTRASONIC...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
CIRCUIT IDEAS 88 • DECEMBER 2006 ELECTRONICS FOR YOU WWW.EFYMAG.COM W e the humans can hear sound of up to 20kHz fre- quency only. This proxim- ity detector works at a frequency of 40 kHz. It uses two specially made ultra- sonic transducers: One transducer emits 40kHz sound, while the other receives 40kHz sound and converts it into electrical variation of the same fre- quency. Fig. 1 shows the block diagram of the ultrasonic proximity detector and Fig. 2 shows its circuit. Mount the transducers (transmitter as well as re- ceiver) about 5 cm apart on a piece of ing CMOS decade counter IC4017 (IC1) is used at the output of the amplifier. IC1 divides the input frequency by ’10,’ so the 40kHz signal becomes 4 kHz, which is within the audible range. The 4kHz signals are fed to op-amp IC 741 (IC2), which is wired as an earphone amplifier. This circuit can be used as an elec- tronic guard for the blind. Keep it (along with 9V battery) in their pocket with earphone plugged to their ear. The transducer modules should be di-
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/24/2011 for the course ECE 231 taught by Professor Damodar during the Spring '10 term at IIT Kanpur.

Page1 / 2

Ultrasonic Proximity detector - CIRCUIT IDEAS ULTRASONIC...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online