Engineering Projects | Ultrasonic Parking Sonar

Ultrasonic Parking Sonar

This circuit electronic is an ultrasonic parking sonar. Based on an ultrasonic amplifier from an article seen on a 1982 magazine, it was once installed on the rear bumper of my Volvo Station Wagon. It served very well for many years. Connecting it to the reverse gear lights, it switches on automatically and shows you the distance to the nearest obstacle (according to his beam) on a led scale. When the last led lights, a buzzer is also activated telling you to stop

Feautures:

• automatic switch on on rear gear


• led-bargraph display


• audible bleep on last led


• "good old" design style, no microcontrollers!
  
  

It works on the sonar principle, sending an ultrasound burst and listening for first echo. The burst generated by the oscillator built around U4D (you must set the frequency using TR2 to have 40 kHz or the maximum sensitivity), U4E buffers the output and U4F boost the signal doubling the voltage span across the TX piezo transducer .