cr0sh
Member
All - how does one go about designing a single-element ultrasonic sensor; that is, one that you pulse the sensor, then switch it to receive (after a short wait to settle the transducer), and it receives the echo (and you do your speed-of-sound calc to measure the distance)?
I've seen plenty of circuits on-line showing how to build a dual-element device (much like the Parallax PING, with transmitter and receiver elements), but I have never seen a circuit for a single transducer, other than the how-to articles for scavenging Polaroid camera sensors.
Now, I have several Polaroid cameras with the ultrasonic sensors, waiting to go under the knife (several Sun 660s and Spectras); I do plan on using them for robotics work in the future. I also have, though, several 24K "ultrasonic" transducers that I want to use, and rather than use them in pairs, I would like to build a similar single transducer system.
I understand that to properly pulse the transducer, you have to set up a dual-ended push-pull type amplifier, but how do you disconnect/reconnect the receive portion of the circuit? I am guessing some kind of transistor/fet switch or something similar, of course, but having never seen such a circuit - I am not sure what can be done here.
Does any one have ideas? Have you seen such a circuit? Have any links? Once again, I would want to use this in a robotics system, so TTL-levels for i/o would be ideal...
I've seen plenty of circuits on-line showing how to build a dual-element device (much like the Parallax PING, with transmitter and receiver elements), but I have never seen a circuit for a single transducer, other than the how-to articles for scavenging Polaroid camera sensors.
Now, I have several Polaroid cameras with the ultrasonic sensors, waiting to go under the knife (several Sun 660s and Spectras); I do plan on using them for robotics work in the future. I also have, though, several 24K "ultrasonic" transducers that I want to use, and rather than use them in pairs, I would like to build a similar single transducer system.
I understand that to properly pulse the transducer, you have to set up a dual-ended push-pull type amplifier, but how do you disconnect/reconnect the receive portion of the circuit? I am guessing some kind of transistor/fet switch or something similar, of course, but having never seen such a circuit - I am not sure what can be done here.
Does any one have ideas? Have you seen such a circuit? Have any links? Once again, I would want to use this in a robotics system, so TTL-levels for i/o would be ideal...