INTERFACE CIRCUIT FOR AN ECHO RANGING SYSTEM

INTERFACE CIRCUIT FOR USE IN AN ECHO RANGING SYSTEM An interface circuit for use in connecting a high frequency piezoelectric transducer to an input stage of an echo ranging system is described. The circuit includes first, second and third control transistors which are selectively switched by a state controller to control the operation of the circuit. The first transistor is controlled to generate a coherent acoustical pulse at a first predetermined time. The second transistor is controlled to damp the transducer output at a second predetermined time following the first predetermined time. The third transistor serves to clamp the input stage of the echo ranging system to ground until the pulse signal has been effectively transmitted. This operation insures the transducer is in a condition to immediately receive an echo pulse despite the proximity of the transducer to the target whose range is being measured. 2995/0000-16:10