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Need to be more specific on what you want to do. A ultrasonic trancducer and LM311 voltage comparator really doesn't tell us much about what you want the circuit to do. The more details you give, the more likely you will find help with your circuit. Most people won't go to the trouble of posting, ley alone digging up a circuit, if you are more then likely to state that it's not what you wanted.
Joey, plug the leads of the transducer into a breadboard. Plug the LM311 in. Connect the rows of the 311 and the transducer appropriately. You may need some additional components but nothing will happen until you hook up a battery.
Harvey, it'll show you the distance upside down. You'll need to use a phased transflux inducer to invert the signal 360° As for the car battery, make sure you install a high capacity fuse between the two posts and install a choke in series with a 555 timer attached to that resistor.
And on my own ranging ideas, anyone have a (preferred) parts supplier suggestion for an inexpensive ~10cm - ~10m and a ~1m - ~50m ranging circuit module? I'd like to put 1-wire solutions in at the fore/aft of my vehicle to serve different purposes.
I.e. parking for the first, possible collision alert for the 2nd (fast delta).