Patent ID: 10739453

Abstract:
The invention relates to an ultrasonic measuring system (10), in particular for measuring distance and/or as a parking aid in vehicles, having an electroacoustic ultrasonic transducer (12) which has a oscillating element (14), does not have a voltage converter, can be alternately operated as an ultrasonic transmitter and an ultrasonic receiver and has a signal connection (16), which is used either as an input or as an output of the ultrasonic transducer (12), and an earth connection (18) which is connected to earth, and a control and evaluation unit (20) for exciting the oscillating element (14) of the ultrasonic transducer (12) to emit ultrasonic waves for operating the ultrasonic transducer (12) during a transmission interval for the purpose of subsequently deactivating the excitation of the oscillating element (14) and attenuating the latter during a decay phase and for receiving and processing ultrasonic waves in a reception interval. The control and evaluation unit (20) has a bridge circuit (28) which is connected to a DC supply voltage (80) and has controllable switches (30 to 40) and a charge storage capacitance (42), the polarity of which can be reversed and which is intended to alternately output a positive and a negative excitation voltage for the signal connection (16) of the ultrasonic transducer (12) during the transmission interval. The control and evaluation unit (20) outputs a voltage pulse of substantially 0 V at the end of the transmission interval for the signal connection (16) of the ultrasonic transducer (12).