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 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...