A multi-channel ultrasonic flowmeter transducer drive circuit and control method thereof

Abstract

The invention belongs to the technical field of electronic circuits, and relates to a multi-channel ultrasonic flowmeter transducer drive circuit and a control method thereof. The driving circuit includes a PWM driving signal generating circuit, a current limiting resistor connected to the PWM driving signal generating circuit, an ultrasonic transducer driving circuit connected to the current limiting resistor, and a power supply circuit providing power for the ultrasonic transducer driving circuit. The PWM driving signal generation circuit outputs the PWM signal generated by the same PWM timer through multiple GPIO ports in time-sharing, and each GPIO port controls an ultrasonic transducer driving circuit through a current limiting resistor to generate an ultrasonic transducer driving signal, and then controls a Ultrasonic transducers emit ultrasonic waves. Multiple GPIO ports are connected to multiple ultrasonic transducer drive circuits in one-to-one correspondence, and multiple ultrasonic transducer drive circuits are connected to multiple ultrasonic transducers in one-to-one correspondence, thereby realizing the multi-channel ultrasonic flowmeter transducer control.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and relates to an ultrasonic transducer driving circuit, in particular to a multi-channel ultrasonic flowmeter transducer driving circuit and a control method thereof. Background technique [0002] In recent years, with the development of ultrasonic measurement technology, various measuring instruments based on ultrasonic technology have also been developed rapidly, such as ultrasonic water meters, ultrasonic gas flow meters, ultrasonic heat meters, etc. In some applications that require high measurement accuracy, the measurement technology based on ultrasonic time difference method is the first choice, and increasing the output channel of ultrasonic measurement can also greatly improve the measurement accuracy. The most widely used in the domestic market are two-channel, four-channel, and six-channel ultrasonic flowmeters based on the ultrasonic time-of-flight method. [0003] In th...

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Problems solved by technology

The disadvantages of this method are: 1) Using one PWM drive signal to drive multiple transducer drive circuits at the same time requires a higher drive capability for the GPIO that outputs the PWM signal

When the number of transducers increases, the corresponding transducer drive circuit increases. When the drive current required by the increased ultrasonic transducer drive circuit exceeds the maximum drive current that the GPIO that outputs the PWM signal can provide, it must be An additional drive circuit is added between the GPIO and the drive circuit of the ultrasonic transducer to enhance the drive capability of the GPIO, and the added drive circuit will lead to increased hardware costs and reduced system reliability; 2) general ultrasonic drive circuit power supplies are relatively low High DC power supply, such as 24V, 36V is more commonly used

When an analog switch is used to switch this type of DC power supply, it will cause a large switching noise in the circuit system, and it will also cause large interference in the adjacent output channels of the analog switch, which means that the isolation of the output channel of the analog switch is relatively high. High requirements; 3) Any analog switch has on-resistance. When the on-resistance is large, the on-resistance will consume part of the power supply energy that needs to be applied to the ultrasonic transducer, thereby affecting the sound of the ultrasonic transducer

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