Ultrasonic Range & Imager


Posted on Feb 5, 2014

This is the electronic schematic of the homebuilt SONAR. Only one piezoelectric transducer is used for both transmit & receive. This transducer is switched from TX to RX via the four 4016 switches. A high gain amplifier stage & rectifier translates the received echoes into voltage pulses. The timing is controlled by the PIC12C508 8-pin microcontro


Ultrasonic Range & Imager
Click here to download the full size of the above Circuit.

ller as it is shown in the following figure: The SONAR system is connected to an analog input of a 68HC11 prototype board. The echoes are sampled at about 18KHz, with 8 bit resolution. The captured data looks like this: The starting decay is due to the residual transducer oscillation. This decay limits the minimum range of the SONAR to about 50 cm. The peak around sample 230 is due to a wall echo. The wall was located 2. 5m away from the SONAR. The next graph shows the echo of a close obstacle (me :) Two successive scans are shown: Then, the SONAR was mechanically scanned with the help of an stepper motor controlled by the 68HC11. The transmitted beam was also focused through a paper horn. The results were: With the use of this lens the beam divergence was greatly reduced, but another problem arises: a notable fraction of the ultrasonic power is reflected back, causing undesired echoes that can be misinterpreted in the short range. The following graph shows the results obtained with the lens. The close echoes in the left are in fact back echoes. In the other hand, the distant echoes are a lot better resolved.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Motion-detection Digital Camera circuit
    voltage frequency synthesizer PLL
    5v regulated solar cell power supply circuit diagram
    arduino How to make a clean amplified microphone analog to digital conversion
    All Transmitter & Receiver schematics
    user-customizable PTT/FSK API of MMTTY
    555 organ circuit
    Variable on-off times circuit using two 555 timers
    Combinatorial and Sequential Circuits
    AC-coupled differential amplifier PGA202
    Simple Valve MW Transmitter circuit 30W



    Top