TRANSMITTER OF ULTRASONIC WAVE

摘要

PURPOSE:To increase the accuracy for measurement of distance, by differentiating the pulse signal to be applied to an ultrasonic wave transducer and thus obtaining the sharp leading edge and trailing edge of the ultrasonic pulse. CONSTITUTION:The output pulse of a monostable multivibrator 2 which is triggered by the signal given from a start pulse generating circuit 1 is applied to multiplier 4. Thus the burst signals of a series of ultrasonic frequency signals are delivered from a carrier frequency oscillating source 3. On the other hand, the output pulse of a monostable multivibrator 5 which is driven by the terminal of the output pulse of the vibrator 2 is applied to an adder circuit 6. Then a reverse phase signal of 1/4-3/4 wavelength of a frequency is applied to the final pulse of the burst signal sent from the multiplier 4. This signal is differentiated by a differentiating circuit 7 and applied to an ultrasonic wave transducer 9 via a power amplifying circuit 8. Thus both the leading edge and trailing edge of the ultrasonic pulse become sharp to increase the accuracy for the measurement of distance.