Ultrasonic set using pulse echo principle - has ultrasonic transmitter sending pulses into object of analysis e.g. internal body organ

摘要

The field-effect transistor (4) is controlled by a sawtooth generator (7) which is, in turn, pulsed by the transmitting pulse. The field-effect transistor can be connected in parallel to the input of the receiver amplifier (5) as part of a voltage divider (3, 4) forming the damping element. The receiver amplifier has connected to its output a processing unit (6) for the echo pulses, e.g. an oscillograph tube to record the pulses. Varying degrees of damping for the ultrasonic pulses are adjusted by means of the damping element acting as a variable resistance. This arrangement provides a solution to the problem of providing an optimum absorption compensation with minimum outlay and without using an amplifier level control.