ADCP emission sound source level adjustable circuit and method

Abstract

The invention provides an ADCP emission sound source level adjustable circuit and method. The method comprises a step of outputting positive voltage and negative voltage in a set range, wherein the absolute value of the outputted positive voltage is equal to the absolute value of the outputted negative voltage, and a step of driving a transducer according to the outputted positive voltage and negative voltage so as to realize the emission of signals of different intensities. According to the circuit and the method, through taking outputted positive and negative voltage values in the set range as the input end voltage of a driving unit, the driving voltage of the transducer is changed, and the sound source level adjustment of the transducer is realized. The disadvantages brought by changing an emission duty ratio are solved, the energy saving can be realized, unnecessary expenses on the hardware can be reduced, and the complexity of system design is reduced.

Description

technical field [0001] The invention relates to the field of water flow velocity measurement, in particular to an ADCP emitting sound source level adjustable circuit and method. Background technique [0002] ADCP, Acoustic Doppler Velocity Profiler, is a device developed based on the principle of Acoustic Doppler to measure the velocity of water body. Among them, the sound source level is an important indicator of the work of the transducer, and its size is used to measure the energy of the signal that the transducer can emit. The larger the transmitted signal, the larger the corresponding echo signal. And we don't need such a large echo signal all the time. For example, when measuring the bottom, the echo signal itself is very large, and it is often necessary to attenuate the signal when the receiving circuit processes it, so the transducer does not need such a large sound source level; for example, when measuring relatively shallow water flow, Because of the short dista...

AI Technical Summary

Problems solved by technology

At this time, if the sound source level cannot be adjusted, on the one hand, it will cause unnecessary loss of energy, and on the other hand, it will bring unnecessary troubles to the receiving circuit amplification processing circuit (because the echo intensity difference between the bottom speed measurement and the water flow speed measurement is 40-50dB )

In the previous technologies, most of the sound source level was changed by changing the duty cycle of the transmitted signal during transmission. The disadvantages of this change are that the adjustable range of changing the duty cycle is small, and it also increases the complexity of the system design, and we generally use D Class A power amplifier is used as the drive circuit of the transducer, and Class D power amplifier is easy to cause waveform distortion when changing the duty cycle (Class A power amplifier is too inefficient, so it is not used)

On the other hand, it is to increase the adjustable gain range in the receiving circuit, which brings unnecessary expenditure to the hardware and unnecessary waste of energy.

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