CN218916441U - Low-power consumption ultrasonic flowmeter - Google Patents

Abstract

The utility model provides a low-power consumption ultrasonic flowmeter, which relates to the technical field of flow detection and comprises the following components: the ultrasonic receiving and transmitting driving chip is connected with at least one group of ultrasonic receiving and transmitting modules, each group of ultrasonic receiving and transmitting modules comprises a transducer, the transducer is connected with an ultrasonic sending driving pin of the ultrasonic receiving and transmitting driving chip, and the transducer is connected with an echo receiving pin of the ultrasonic receiving and transmitting driving chip through a signal processing module; the control chip is respectively connected with the ultrasonic wave receiving and transmitting driving chip and a power supply battery, the power supply battery is used for supplying power to the control chip, the control chip is used for periodically waking up to supply power to the ultrasonic wave receiving and transmitting driving chip, and a low-speed clock is provided for controlling the ultrasonic wave receiving and transmitting driving chip to drive the ultrasonic wave receiving and transmitting module to carry out periodic flow measurement and receiving the flow measurement result of the ultrasonic wave receiving and transmitting driving chip. The utility model reduces the power consumption of the ultrasonic flowmeter and enhances the anti-interference capability.

Description

Low-power consumption ultrasonic flowmeter

Technical Field

The utility model relates to the technical field of flow detection, in particular to a low-power consumption ultrasonic flowmeter.

Background

An ultrasonic flowmeter is a meter for measuring flow by detecting the action of fluid flow on an ultrasonic beam (or ultrasonic pulse), and consists of an ultrasonic transducer, an electronic circuit and a flow display and accumulation system. The ultrasonic wave transmitting transducer converts the electric energy into ultrasonic energy and transmits the ultrasonic energy into the fluid to be measured, and the ultrasonic wave signal received by the receiver is amplified by the electronic circuit and converted into an electric signal representing the flow rate to be supplied to the display and integrating instrument for display and integration. Thus, the detection and display of the flow rate are realized.

At present, domestic ultrasonic flow meters are more in products and lower in cost, but the overall performance is not high, and foreign ultrasonic flow meters are better in precision, performance and the like, but are high in price, so that a large number of applications in industry are limited. While the conventional ultrasonic flowmeter performs primary fluid flow rate measurement in a fixed period, the measurement interval time should approach infinity in theory to accurately reflect the fluid flow rate, the smaller the measurement period is, the larger the power consumption is, which is the first factor to be considered for battery-powered flowmeters.

Therefore, there is a need to develop a new low-power consumption ultrasonic flowmeter to make up for the shortages of the existing detection technology and reduce the power consumption of the ultrasonic flowmeter.

Disclosure of Invention

Aiming at the problems in the prior art, the utility model provides a low-power consumption ultrasonic flowmeter, which comprises:

the ultrasonic transceiver driving chip is connected with at least one group of ultrasonic transceiver modules, each group of ultrasonic transceiver modules comprises a transducer, the transducer is connected with an ultrasonic transmission driving pin of the ultrasonic transceiver driving chip, and the transducer is connected with an echo receiving pin of the ultrasonic transceiver driving chip through a signal processing module;

the control chip is respectively connected with the ultrasonic wave receiving and transmitting driving chip and a power supply battery, the power supply battery is used for supplying power to the control chip, the control chip is used for periodically waking up to supply power to the ultrasonic wave receiving and transmitting driving chip, and a low-speed clock is provided to control the ultrasonic wave receiving and transmitting driving chip to drive the ultrasonic wave receiving and transmitting module to carry out periodic flow measurement, and the flow measurement result of the ultrasonic wave receiving and transmitting driving chip is received.

Preferably, the signal processing module includes:

the input end of the filtering unit is connected with the transducer;

and the input end of the amplifying unit is connected with the output end of the filtering unit, and the output end of the amplifying unit is connected with the corresponding echo receiving pin.

Preferably, the filtering unit includes:

one end of the first resistor is connected with the transducer, the other end of the first resistor is connected with one end of a first capacitor, and the other end of the first capacitor is grounded;

one end of the second capacitor is connected with the first resistor and the first capacitor respectively;

and one end of the second resistor is respectively connected with the other end of the second capacitor and the input end of the amplifying unit, and the other end of the second resistor is grounded.

Preferably, the amplifying unit includes:

one end of the third resistor is connected with the output end of the filtering unit, and the other end of the third resistor is connected with the non-inverting input end of an operational amplifier;

one end of the fourth resistor is grounded, and the other end of the fourth resistor is connected with the inverting input end of the operational amplifier;

one end of the fifth resistor is connected with the other end of the fourth resistor, and the other end of the fifth resistor is connected with the output end of the operational amplifier;

and the output end of the operational amplifier is connected with the echo receiving pin.

Preferably, the flow measuring device further comprises a display module, wherein the display module is connected with the control chip and is used for displaying the flow measuring result.

Preferably, the low-power consumption ultrasonic flowmeter further comprises a communication module connected with the control chip, and the communication module is used for transmitting the flow measurement result received by the control chip to an external master station.

Preferably, the ultrasonic transceiver modules of the low-power-consumption ultrasonic flowmeter are two groups, and the ultrasonic transmission driving pins and the echo receiving pins are correspondingly two.

Preferably, the low-power consumption ultrasonic flowmeter further comprises a temperature measuring component, and the temperature measuring component is connected with the ultrasonic receiving and transmitting driving chip.

Preferably, the low-power consumption ultrasonic flowmeter further comprises: the control chip is connected with the ultrasonic wave receiving and transmitting driving chip through the first PMOS tube and supplies power for the ultrasonic wave receiving and transmitting driving chip through the first PMOS tube.

Preferably, the low-power consumption ultrasonic flowmeter further comprises:

the grid electrode of the second PMOS tube is connected with the control chip, the source electrode of the second PMOS tube is connected with the power supply battery, and the drain electrode of the second PMOS tube is connected with the anode of a capacitor;

the grid electrode of the third PMOS tube is connected with a power supply output selection pin of the communication module, the source electrode of the third PMOS tube is connected with a voltage stabilizing output pin of the communication module, the drain electrode of the third PMOS tube is connected with the positive electrode of the capacitor, and the negative electrode of the capacitor is grounded;

the drain electrode of the second PMOS tube is also connected with the source electrode of the first PMOS tube, the grid electrode of the first PMOS tube is connected with the control chip, and the drain electrode of the first PMOS tube is connected with the ultrasonic wave receiving and transmitting driving chip.

The technical scheme has the following advantages or beneficial effects:

1) The circuit structure is simple;

2) The ultrasonic flowmeter has low power consumption;

3) The ultrasonic flowmeter has strong anti-interference capability and can process tiny signals.

Drawings

FIG. 1 is a block diagram of a low power ultrasonic flow meter unit in accordance with a preferred embodiment of the present utility model;

FIG. 2 is a circuit diagram of a low power ultrasonic flow meter filter unit in accordance with a preferred embodiment of the present utility model;

FIG. 3 is a circuit diagram of an amplifying unit of a low power ultrasonic flowmeter according to a preferred embodiment of the present utility model;

FIG. 4 is a schematic diagram showing the circuit connection of the first PMOS transistor, the second PMOS transistor and the third PMOS transistor according to the preferred embodiment of the present utility model.

Detailed Description

The utility model will now be described in detail with reference to the drawings and specific examples. The present utility model is not limited to the embodiment, and other embodiments may fall within the scope of the present utility model as long as they conform to the gist of the present utility model.

In accordance with the foregoing problems with the prior art, the present utility model provides a low power consumption ultrasonic flow meter, as shown in fig. 1, which specifically comprises:

the ultrasonic wave receiving and transmitting driving chip 1 is connected with at least one group of ultrasonic wave receiving and transmitting modules 2, each group of ultrasonic wave receiving and transmitting modules 2 comprises a transducer 21, the transducer 21 is connected with an ultrasonic wave sending driving pin of the ultrasonic wave receiving and transmitting driving chip 1, and the transducer 21 is connected with an echo receiving pin of the ultrasonic wave receiving and transmitting driving chip 1 through a signal processing module 3.

The control chip 4 is respectively connected with the ultrasonic wave receiving and transmitting driving chip 1 and a power supply battery 5, the power supply battery 5 is used for supplying power to the control chip 4, the control chip 4 is used for periodically waking up to supply power to the ultrasonic wave receiving and transmitting driving chip 1, and a low-speed clock is provided for controlling the ultrasonic wave receiving and transmitting driving chip 1 to drive the ultrasonic wave receiving and transmitting module 2 to carry out periodic flow measurement and receiving the flow measurement result of the ultrasonic wave receiving and transmitting driving chip 1.

Preferably, in this embodiment, the control chip 4 is a single chip microcomputer of the type MSP430F4152, and the MSP430F4152 is a 16-bit ultra-low power micro control processor, and has a 16KB flash memory, a 512B random access memory, a 10-bit analog-to-digital converter, a 10-bit universal serial communication interface, an analog comparator, 56I/O ports, and an LCD driver.

Preferably, in this embodiment, the ultrasonic transceiver driving chip 1 selects an MS1030 ultrasonic measuring chip, and the MS1030 is a high-precision measuring circuit for ultrasonic flow, which has the characteristics of high precision, high stability and high efficiency; the measuring precision is up to 15PS, the measuring range is very wide, the offset programmable range of the internal comparator is +/-127 mV under the condition of the first wave mode, and the comparison bias voltage of +/-64 mV is additionally increased; the maximum of 8 echo pulses are measured in one direction, a forward and backward flow automatic measurement mode is embedded, and after measurement is completed, 8 echo pulse values of forward flow and backward flow and the sum of 8 echo pulses are provided with independent result registers.

Specifically, in the present embodiment, the control chip 4 has five low power consumption modes: LPM0, LPM1, LPM2, LPM3, LPM4, wherein mode LPM4 only retains RAM contents, the master and slave clocks all stop to enter deep sleep, with the lowest power consumption, but this mode can only be awakened by external interrupts; the measurement must be periodically performed, and a timer is required to wake up, so that only the mode LPM3 can be used, the macro instruction LPM3 is executed to enter the LPM3 sleep mode, the auxiliary clock of the mode is still working, and the timer normally counts up to the set time to interrupt the wake-up MSP430F4152; the control chip 4 has a configuration function on the ultrasonic wave receiving and transmitting driving chip 1, the ultrasonic wave flight time difference measurement is started, the control chip 4 can wake up the ultrasonic wave receiving and transmitting driving chip 1 periodically under the mode LPM3, the control chip 4 provides a low-speed clock for the ultrasonic wave receiving and transmitting driving chip 1, when the ultrasonic wave receiving and transmitting driving chip 1 receives the low-speed clock from the control chip 4, the internal circuit of the ultrasonic wave receiving and transmitting driving chip 1 starts to overturn, the ultrasonic wave receiving and transmitting driving chip 1 starts to drive the ultrasonic wave receiving and transmitting module 2 to transmit and receive ultrasonic wave pulses, and then the ultrasonic wave receiving and transmitting driving chip 1 transmits a measurement result to the control chip 4.

In a preferred embodiment of the present utility model, as shown in fig. 1, the signal processing module includes:

the input end of the filtering unit 31 is connected with the transducer 21;

the input end of the amplifying unit 32 is connected with the output end of the filtering unit 31, and the output end of the amplifying unit 32 is connected with the corresponding echo receiving pin.

In a preferred embodiment of the present utility model, as shown in fig. 2, the filtering unit 31 includes:

one end of the first resistor R1 is connected with the transducer, the other end of the first resistor R1 is connected with one end of a first capacitor C1, and the other end of the first capacitor C1 is grounded;

one end of the second capacitor C2 is connected with the first resistor R1 and the first capacitor C1 respectively;

and one end of the second resistor R2 is respectively connected with the other end of the second capacitor C2 and the input end of the amplifying unit 32, and the other end of the second resistor R2 is grounded.

In a preferred embodiment of the present utility model, as shown in fig. 3, the amplifying unit includes:

one end of the third resistor R3 is connected with the output end of the filtering unit 31, and the other end of the third resistor R3 is connected with the non-inverting input end of an operational amplifier U1;

one end of the fourth resistor R4 is grounded, and the other end of the fourth resistor R4 is connected with the inverting input end of the operational amplifier U1;

one end of the fifth resistor R5 is connected with the other end of the fourth resistor R4, and the other end of the fifth resistor R5 is connected with the output end of the operational amplifier U1;

the output end of the operational amplifier U1 is connected with an echo receiving pin.

In the preferred embodiment of the present utility model, the ultrasonic transceiver modules 2 are two groups, and the ultrasonic transmission driving pins and the echo receiving pins are correspondingly two.

Specifically, in the present embodiment, the ultrasonic transceiver module 2 includes an upstream transducer 211 and a downstream transducer 212.

Preferably, in this embodiment, the filtering unit 31 selects a second-order passive bandpass filter, which can filter the ultrasonic wave received signal, suppress high-frequency noise and low-frequency noise in the signal, and play an anti-aliasing role, where the value of the first resistor R1 is 1kΩ, the value of the first capacitor C1 is 32pf, the value of the second resistor R2 is 150 Ω, the value of the second capacitor C2 is 5nf, the center frequency of the filter is 1MHz, the lower limit frequency is 200kHz, and the upper limit frequency is 5MHz;

preferably, in the embodiment, the operational amplifier U1 in the amplifying unit 32 is a MAX4128 chip, and the MAX4128 chip has the characteristics of dual-path, high bandwidth, low power consumption, single power supply, full swing input/output, etc., and the working current is smaller, the power supply range is from 2.7V to 6.5V, and the gain bandwidth of 25MHz, the value of the fourth resistor R4 is 5.1kΩ, the value of the fifth resistor R5 is 51kΩ, and the amplification factor of the amplifying unit 32 is 10 times;

specifically, in this embodiment, the ultrasonic transceiver driving chip 1 has two measurement modes, the first measurement mode is a first wave measurement mode, a threshold voltage is formed by the sum of a bias voltage (-128 mV-126 mV) of the first wave comparator and a bias voltage (-128-124 mV) of the built-in comparator to detect a first safe echo pulse, and then the flight time of the echo is determined according to the position of the first wave, and the pulse width of the first wave is measured and maintained at the same time; after the first wave measurement is completed, the bias voltage of the first wave comparator is automatically reset, and the bias voltage of the built-in comparator is used as threshold voltage to measure the subsequent echo pulse; the second measurement mode is an embedded forward and backward flow automatic measurement mode, and the measurement mode not only can improve the measurement speed, but also can greatly reduce the measurement power consumption; after the control chip 4 configures the measuring mode of the ultrasonic transceiver driving chip 1, the ultrasonic transceiver driving chip 1 directly drives the upstream transducer 21 in the ultrasonic transceiver module 2 to transmit ultrasonic waves, the upstream transducer 211 transmits a certain number of ultrasonic pulses, the downstream transducer 212 receives echo pulses, the received echo pulses are filtered by the filtering unit 31 and amplified by the amplifying unit 32, and the received ultrasonic pulses are transmitted back to the ultrasonic transceiver driving chip 1, which is a downstream measuring process; in the countercurrent measurement process, the ultrasonic wave receiving and transmitting driving chip 1 drives the downstream transducer 212 in the ultrasonic wave receiving and transmitting module 2 to transmit a certain amount of ultrasonic waves, the upstream transducer 211 of the ultrasonic wave receiving and transmitting module 2 receives echo pulses, the echo pulses are filtered by the filtering unit and amplified by the amplifying unit, and the received ultrasonic waves are transmitted back to the ultrasonic wave receiving and transmitting driving chip 1;

in a preferred embodiment of the present utility model, as shown in fig. 1, the flow meter further includes a display module 6, wherein the display module 6 is connected to the control chip 4, and the display module 6 is used for displaying the flow measurement result.

Preferably, in the present embodiment, the display module 6 is a segment LCD module;

specifically, in this embodiment, the display module 6 is connected to the control chip 4, and only when the display key is pressed, the control chip 4 converts the flow measurement result measured by the ultrasonic transceiver driving chip 1 into a corresponding segment code and transmits the segment code to the LCD driving pin, and the LCD driving pin drives the lighting display module 6.

In the preferred embodiment of the present utility model, as shown in fig. 1, the device further comprises a communication module 7 connected to the control chip 4, where the communication module 7 is configured to transmit the flow measurement result received by the control chip 4 to an external master station.

Preferably, in this embodiment, the communication module 7 selects a TSS721 interface chip, where the TSS721 interface chip meets international EN1434-3 standard, is in a nonpolar connection, has an operating temperature of-25 ℃ to 85 ℃, has a power failure prevention function, supports remote power supply, and can provide a 3.3v voltage stabilizing source and a half duplex serial port communication rate of 9600bps at the highest;

specifically, in the present embodiment, the communication module 7 may supply a 3.3V regulated power when the bus configuration is valid.

In the preferred embodiment of the present utility model, as shown in fig. 1, the present utility model further comprises a temperature measuring component 8, and the temperature measuring component is connected to the ultrasonic transceiver driving chip 1.

Preferably, in this embodiment, the temperature measuring component 8 may measure temperature by using a PT1000 temperature sensor;

specifically, in the present embodiment, after the ultrasonic transceiver driving chip 1 measures the fluid temperature through the PT1000, the measured temperature value is transmitted to the control chip 4.

In a preferred embodiment of the present utility model, as shown in fig. 1, the method further comprises: the control chip 4 is connected with the ultrasonic wave receiving and transmitting driving chip 1 through the first PMOS tube 9 and supplies power to the ultrasonic wave receiving and transmitting driving chip 1 through the first PMOS tube 9.

Specifically, in this embodiment, in a measurement period, the micro control chip 4 turns on the first PMOS transistor to supply power to the ultrasonic transceiver driver chip 1 when measurement is required, and after measurement is completed, the micro control chip 4 turns off the first PMOS transistor to stop supplying power to the ultrasonic transceiver driver chip 1.

In a preferred embodiment of the present utility model, as shown in fig. 1 and 4, the method further comprises:

the grid electrode of the second PMOS tube 10 is connected with the control chip, the source electrode of the second PMOS tube 10 is connected with the power supply battery 5, and the drain electrode of the second PMOS tube 10 is connected with the anode of a capacitor 12;

the grid electrode of the third PMOS tube 11 is connected with a power supply output selection pin of the communication module 7, the source electrode of the third PMOS tube 11 is connected with a voltage stabilizing output pin of the communication module 7, the drain electrode of the third POMS tube 11 is connected with the positive electrode of the capacitor 12, and the negative electrode of the capacitor 12 is grounded;

the drain electrode of the second PMOS tube 10 is also connected with the source electrode of the first PMOS tube 9, the grid electrode of the first PMOS tube 9 is connected with the control chip 4, and the drain electrode of the first PMOS tube 9 is connected with the ultrasonic wave receiving and transmitting driving chip 1.

Specifically, in this embodiment, in a measurement period, the measurement time is much smaller than the sleep time of the control chip 4, and in the sleep time of the control chip 4, the ultrasonic transceiver driving chip 1 is not powered, no quiescent current is generated inside, and the communication module 7 opens the third PMOS transistor 10 to store the electric energy in the capacitor 12. The communication module 7 may obtain power from the MBUS bus and provide the power to the regulated input pin VDD, and control the third PMOS transistor 11 to charge the capacitor through the power supply output select pin VS. The first PMOS transistor 9 is a switch for controlling the power supply to the ultrasonic transceiver driver chip 1, and is turned on when the measurement is needed, and the communication module 7 does not have electric energy to charge the capacitor 12 when the MBUS bus is invalid, so that the second PMOS transistor 10 is turned on while the first PMOS transistor 9 is turned on, so as to conduct the power supply line between the power supply battery 5 and the ultrasonic transceiver driver chip 1.

The foregoing description is only illustrative of the preferred embodiments of the present utility model and is not to be construed as limiting the scope of the utility model, and it will be appreciated by those skilled in the art that equivalent substitutions and obvious variations may be made using the description and drawings, and are intended to be included within the scope of the present utility model.

Claims (10)

1. A low power ultrasonic flow meter, comprising:

the ultrasonic transceiver driving chip is connected with at least one group of ultrasonic transceiver modules, each group of ultrasonic transceiver modules comprises a transducer, the transducer is connected with an ultrasonic transmission driving pin of the ultrasonic transceiver driving chip, and the transducer is connected with an echo receiving pin of the ultrasonic transceiver driving chip through a signal processing module;

the control chip is respectively connected with the ultrasonic wave receiving and transmitting driving chip and a power supply battery, the power supply battery is used for supplying power to the control chip, the control chip is used for periodically waking up to supply power to the ultrasonic wave receiving and transmitting driving chip, and a low-speed clock is provided to control the ultrasonic wave receiving and transmitting driving chip to drive the ultrasonic wave receiving and transmitting module to carry out periodic flow measurement, and the flow measurement result of the ultrasonic wave receiving and transmitting driving chip is received.

2. The low power consumption ultrasonic flow meter of claim 1, wherein the signal processing module comprises:

the input end of the filtering unit is connected with the transducer;

and the input end of the amplifying unit is connected with the output end of the filtering unit, and the output end of the amplifying unit is connected with the corresponding echo receiving pin.

3. The low power consumption ultrasonic flow meter of claim 2, wherein the filtering unit comprises:

one end of the first resistor is connected with the transducer, the other end of the first resistor is connected with one end of a first capacitor, and the other end of the first capacitor is grounded;

one end of the second capacitor is connected with the first resistor and the first capacitor respectively;

and one end of the second resistor is respectively connected with the other end of the second capacitor and the input end of the amplifying unit, and the other end of the second resistor is grounded.

4. The low power consumption ultrasonic flow meter of claim 2, wherein the amplifying unit comprises:

one end of the third resistor is connected with the output end of the filtering unit, and the other end of the third resistor is connected with the non-inverting input end of an operational amplifier;

one end of the fourth resistor is grounded, and the other end of the fourth resistor is connected with the inverting input end of the operational amplifier;

one end of the fifth resistor is connected with the other end of the fourth resistor, and the other end of the fifth resistor is connected with the output end of the operational amplifier;

and the output end of the operational amplifier is connected with the echo receiving pin.

5. The low power consumption ultrasonic flow meter of claim 1, further comprising a display module coupled to the control chip, the display module configured to display the flow measurement.

6. The low power consumption ultrasonic flow meter of claim 1, further comprising a communication module coupled to the control chip, the communication module configured to transmit the flow measurement received by the control chip to an external master station.

7. The low power consumption ultrasonic flow meter of claim 1, wherein the ultrasonic transceiver modules are in two groups, and the ultrasonic transmission driving pin and the echo receiving pin are respectively two.

8. The low power consumption ultrasonic flow meter of claim 1, further comprising a temperature measurement component coupled to the ultrasonic transceiver driver chip.

9. The low power consumption ultrasonic flow meter of claim 6, further comprising: the control chip is connected with the ultrasonic wave receiving and transmitting driving chip through the first PMOS tube and supplies power for the ultrasonic wave receiving and transmitting driving chip through the first PMOS tube.

10. The low power consumption ultrasonic flow meter of claim 9, further comprising:

the grid electrode of the second PMOS tube is connected with the control chip, the source electrode of the second PMOS tube is connected with the power supply battery, and the drain electrode of the second PMOS tube is connected with the anode of a capacitor;

the grid electrode of the third PMOS tube is connected with the power supply output selection pin of the communication module, the source electrode of the third PMOS tube is connected with the voltage stabilizing output pin of the communication module, the drain electrode of the third PMOS tube is connected with the positive electrode of the capacitor, and the negative electrode of the capacitor is grounded;

the drain electrode of the second PMOS tube is also connected with the source electrode of the first PMOS tube, the grid electrode of the first PMOS tube is connected with the control chip, and the drain electrode of the first PMOS tube is connected with the ultrasonic wave receiving and transmitting driving chip.

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