A low-noise switched circuit for multichannel ultrasonic signal reception

Abstract

The utility model relates to ultrasonic sensor technical field discloses a kind of low-noise switch switching circuit for multichannel ultrasonic wave signal reception, including two groups of multistage transducer receiving circuit isolated physically, for realizing the signal reception of two mutually excited ultrasonic sensor;The multistage transducer receiving circuit includes the first stage transducer receiving circuit and the second stage transducer receiving circuit connected;The first stage transducer receiving circuit includes several transducer receiving signal channels connected in parallel, and several transducer receiving signal channels are connected into a multiple-select one switch;The second stage transducer receiving circuit includes at least two parallelly connected noise reduction channels, one of which is grounded, the other is connected with output, and two noise reduction channels are connected into a two-way switch.The purpose is to adopt the mode of three-level switch series connection, to adopt the mode of disconnecting protection and grounding when switch is opened, to minimize the influence on the selection signal.

Description

Technical Field

[0001] This utility model relates to the field of ultrasonic sensor technology, and in particular to a low-noise switching circuit for receiving multi-channel ultrasonic signals. Background Technology

[0002] In products such as ultrasonic flow meters, ultrasonic anemometers, and ultrasonic level gauges, multi-channel measurement methods are used to increase measurement accuracy. During channel switching, the ultrasonic echo signal amplitude is small (mV level), and the echo signal is often affected by noise, thus affecting the measurement accuracy.

[0003] Conventional multi-channel switching circuits, such as Figure 1 As shown, a parallel multi-channel switch method is used, with only one switch turned on at a time. The problem with this method is that distributed capacitance, inductance, and other factors between channels can interfere with the signal of the selected channel, thus affecting the measurement accuracy.

[0004] Patent CN212463164U discloses a programmable multi-channel switching output device for an ultrasonic power amplifier, which solves the problem that ultrasonic power amplifiers only have a single channel and are difficult to apply in research such as ultrasonic guided wave synthetic aperture total focusing imaging, which requires the transmitter source to be able to quickly switch between multiple power channels in a time-division manner. Its solution mainly targets the output channel, which is different from the switching of the receiving channel of the ultrasonic sensor. Utility Model Content

[0005] To address the existing problems, this utility model provides a low-noise switching circuit for multi-channel ultrasonic signal reception. It aims to minimize the impact on the gating signal by using a three-stage series switch and employing disconnection protection and grounding when the switch is open.

[0006] To achieve the above objectives, the present invention provides the following technical solution.

[0007] A low-noise switching circuit for receiving multi-channel ultrasonic signals includes two physically isolated multi-stage transducer receiving circuits for receiving signals from two mutually excited ultrasonic sensors. The multi-stage transducer receiving circuit includes a first-stage transducer receiving circuit and a second-stage transducer receiving circuit connected in series. The first-stage transducer receiving circuit includes several transducer receiving signal channels connected in parallel, and these channels are connected to a multiplexer switch. The second-stage transducer receiving circuit includes at least two parallel noise reduction channels, one of which is grounded, and the other is connected to the output terminal. The two noise reduction channels are connected to a two-to-one switch.

[0008] As a further improvement of this utility model, both the first-stage transducer receiving circuit and the second-stage transducer receiving circuit include a controller input interface and an enable coupling interface, which are respectively used to receive a multi-select switch signal from the controller and to realize ground control coupling between the two sets of different multi-stage transducer receiving circuits.

[0009] As a further improvement of this utility model, the enable coupling interface of the first stage transducer receiving circuit of a multi-stage transducer receiving circuit is connected to the enable coupling interface circuit of the second stage transducer receiving circuit of another multi-stage transducer receiving circuit.

[0010] As a further improvement of this utility model, it also includes a third-stage transducer receiving circuit; the third-stage transducer receiving circuit is connected to the second-stage transducer receiving circuit; the third-stage transducer receiving circuit includes two parallel output channels, and the two output channels are respectively connected to the second-stage transducer receiving circuits of two different multi-stage transducer receiving circuits.

[0011] As a further improvement of this utility model, the third-stage transducer receiving circuit also includes a controller input interface and an output coupling interface, which are used to receive a multi-select switch signal from the controller and to realize output control coupling between the two sets of multi-stage transducer receiving circuits, respectively.

[0012] As a further improvement of this utility model, the output coupling interface is connected to the enable coupling interface circuit of the first stage transducer receiving circuit of two different multi-stage transducer receiving circuits.

[0013] As a further improvement of this utility model, the third-stage transducer receiving circuit also includes a grounding interface for protective grounding.

[0014] As a further improvement of this utility model, the physical isolation is achieved by placing two sets of multi-stage transducer receiving circuits in different electronic devices.

[0015] As a further improvement of this utility model, the isolation between the two sets of multi-stage transducer receiving circuits is better than -60dB.

[0016] As a further improvement of this utility model, both the multiple-choice switch and the two-choice switch are digital switches.

[0017] This utility model has the following beneficial effects: By using two physically isolated multi-stage transducer receiving circuits, mutual interference during the signal reception process of two mutually excited ultrasonic sensors can be effectively avoided, improving the accuracy and stability of signal reception. The first-stage transducer receiving circuit has several parallel transducer signal channels, which can be flexibly selected via a multiplexer switch to meet signal reception requirements under different conditions. The second-stage transducer receiving circuit has at least two parallel noise reduction channels; one is grounded to eliminate some noise, and the other is connected to the output terminal to further optimize the output signal. A two-to-one switch reduces the impact of noise on ultrasonic signal reception, improving signal quality.

[0018] Preferably, the controller input interface facilitates the reception of multi-select switch signals from the controller, enabling precise control of the on / off states of switches in each stage of the transducer receiving circuit, and achieving flexible regulation of the signal reception process. The enable coupling interface enables grounding control coupling between the two sets of multi-stage transducer receiving circuits, helping to unify and coordinate the grounding states of the two circuits, optimize the grounding effect, further reduce noise interference, and improve the stability and reliability of the entire circuit.

[0019] Preferably, this connection method enables the first stage of one circuit to establish a connection with the second stage of another circuit in terms of enabling coupling, which can more effectively realize the collaborative work between the two circuits, optimize the grounding control coupling effect, enhance the overall anti-interference capability of the circuit, and ensure the accuracy and stability of signal reception.

[0020] Preferably, a third-stage transducer receiving circuit is added and connected to the second-stage transducer receiving circuit, with its two output channels respectively connected to the second stage of two different multi-stage transducer receiving circuits, further enriching the signal processing and output paths. This structure allows for more detailed integration and optimization of the signals processed by the first two stages, helping to improve signal quality and output stability, and meeting more complex ultrasonic signal reception requirements.

[0021] Preferably, the controller input interface of the third-stage transducer receiving circuit can receive controller signals to achieve precise control of the switches in the third-stage circuit, and further flexibly adjust the signal processing and output process. The output coupling interface realizes output control coupling between the two sets of multi-stage transducer receiving circuits, which enables the two sets of circuits to work together better in the output stage, optimize the output signal, and improve the performance and stability of the entire circuit system.

[0022] Preferably, the output coupling interface is connected to the enable coupling interface circuit of the first-stage transducer receiving circuit of two different multi-stage transducer receiving circuits. This connection method establishes a closer connection between each stage of the circuit, which can more comprehensively coordinate the working state of the entire circuit system, and perform unified optimization from the initial stage of signal reception to the output stage, effectively improving the circuit's anti-interference capability and signal processing effect.

[0023] Preferably, the grounding interface is used for protective grounding. When abnormal conditions such as overvoltage or overcurrent occur in the circuit, it can conduct the current to the ground, avoid damage to the electronic components in the circuit, ensure the safe and stable operation of the circuit, and extend the service life of the circuit.

[0024] Preferably, placing the two sets of multi-stage transducer receiving circuits in different electronic devices to achieve physical isolation can minimize electromagnetic interference and thermal interference between the two sets of circuits, provide a relatively independent and stable working environment for each set of circuits, and further improve the accuracy and reliability of signal reception. This is especially suitable for multi-channel ultrasonic signal reception scenarios with high signal quality requirements.

[0025] Preferably, the isolation between the two sets of multi-stage transducer receiving circuits is better than -60dB, indicating that the two sets of circuits have high isolation performance, which can effectively prevent signal leakage and mutual interference, and ensure that each set of circuits independently and accurately receives and processes its corresponding ultrasonic sensor signals, thereby improving the performance and stability of the entire multi-channel ultrasonic signal receiving system.

[0026] Optionally, a digital switch can be used, which has a simple structure and can quickly and accurately open and close the channel. Attached Figure Description

[0027] The accompanying drawings described herein are for illustrative purposes only and do not limit the scope of this invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings: Figure 1 A schematic diagram of a circuit for two mutually excitable ultrasonic sensors; Figure 2 A schematic diagram of the receiving signal channels of two mutually excited ultrasonic sensors that are not physically isolated; Figure 3 A schematic diagram of the receiving signal channel switch for two mutually excited ultrasonic sensors that are not physically isolated; Figure 4 This is a schematic diagram of the secondary structure of a low-noise switching circuit for multi-channel ultrasonic signal reception as described in Example 1. Figure 5 This is a schematic diagram of a three-stage structure of a low-noise switching circuit for multi-channel ultrasonic signal reception as described in Example 2. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0029] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0030] Unless otherwise defined below, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] In traditional switching methods, such as Figure 1 As shown, assuming the excitation voltage is 24V, circuit A's CH_A1 channel transmits the signal, and circuit B's CH_B1 channel receives the signal. The isolation between the channels is -60dB (attenuation by 1000 times). Since both the ultrasonic transmitting and receiving circuits are connected to the sensor, the interference signal coupled from the CH_A1 channel to the CH_B1 channel is 24 / 1000 = 24mV. This signal is almost identical in amplitude to the sensor's received signal and is unavoidable. Moreover, as... Figure 2 and Figure 3 As shown, in the traditional switching method, the A group circuit and the B group circuit are set in the same chip or module, and the isolation is even less than -60dB. Under the same excitation voltage, the signal interference is stronger.

[0032] Example 1 like Figure 4 As shown, a low-noise switching circuit for multi-channel ultrasonic signal reception includes two physically isolated sets of multi-stage transducer receiving circuits, set A and set B, for receiving signals from two mutually excited ultrasonic sensors.

[0033] The multi-stage transducer receiving circuit includes a first-stage transducer receiving circuit and a second-stage transducer receiving circuit connected in series. The first-stage transducer receiving circuit includes several transducer receiving signal channels connected in parallel, and these channels are connected to a multiplexer switch. The second-stage transducer receiving circuit includes at least two parallel noise reduction channels, one of which is grounded, and the other is connected to the output terminal. The two noise reduction channels are connected to a two-to-one switch. Specifically, as shown... Figure 4 As shown, the A-group multi-stage transducer receiving circuit includes a first-stage transducer receiving circuit U1 and a second-stage transducer receiving circuit U3. U1 is a multiplexer switch for channels CH_A1 to CH_An, and U2 is a two-way switch for channels A_K0 (ground) and A_K1. The B-group multi-stage transducer receiving circuit includes a first-stage transducer receiving circuit U2 and a second-stage transducer receiving circuit U4. U2 is a multiplexer switch for channels CH_B1 to CH_Bn, and U4 is a two-way switch for channels B_K0 (ground) to B_K1.

[0034] Both the first-stage transducer receiving circuit and the second-stage transducer receiving circuit include a controller input interface and an enable coupling interface, used to receive a multiple-choice switch signal from the controller and to achieve grounding control coupling between the two sets of multi-stage transducer receiving circuits, respectively. Specifically, the controller input interface of the first-stage transducer receiving circuit U1 is A2, and the enable coupling interface is EN_1. The controller input interface of the second-stage transducer receiving circuit U3 is A_C1, and the enable coupling interface is A_C0. The controller input interface of the first-stage transducer receiving circuit U2 is B2, and the enable coupling interface is EN_2. The controller input interface of the second-stage transducer receiving circuit U4 is B_C1, and the enable coupling interface is B_C0.

[0035] The enable coupling interface of the first stage transducer receiving circuit of one multi-stage transducer receiving circuit is connected to the enable coupling interface circuit of the second stage transducer receiving circuit of another multi-stage transducer receiving circuit. Specifically, EN_1 is connected to B_C1, and A_C0 is connected to EN_2.

[0036] The physical isolation is achieved by placing the two sets of multi-stage transducer receiving circuits in different electronic devices. Preferably, the isolation between the two sets of multi-stage transducer receiving circuits is better than -60dB.

[0037] Both the multiple-choice switch and the two-choice switch are digital switches.

[0038] Example 2 The difference between this embodiment and Embodiment 1 is that: 1) It also includes a third-stage transducer receiving circuit; the third-stage transducer receiving circuit is connected to the second-stage transducer receiving circuit; the third-stage transducer receiving circuit includes two parallel output channels, and the two output channels are respectively connected to the second-stage transducer receiving circuits of two different multi-stage transducer receiving circuits.

[0039] 2) The third-stage transducer receiving circuit also includes a controller input interface and an output coupling interface, which are used to receive the multi-select switch signal from the controller and to realize the output control coupling between the two sets of multi-stage transducer receiving circuits, respectively.

[0040] 3) The output coupling interface is connected to the enable coupling interface circuit of the first stage transducer receiving circuit of the two sets of different multi-stage transducer receiving circuits respectively.

[0041] like Figure 5 As shown, U1 and U2 are the first-stage transducer receiving circuits used for signal selection. U1 and U2 are multiplex switches and are equipped with EN enable coupling interfaces.

[0042] Because the ultrasonic transmission signal power is relatively high, in order to reduce the impact of ultrasonic transmission on the receiving channel, groups A (CH_A1-CH_An) and groups B (CH_B-CH_Bn) are physically separated to reduce the coupling between channels. When selecting group A signals, the group A enable signal EN_1 should be turned on, and the group B enable signal EN_2 should be turned off to further reduce the coupling between channels.

[0043] U3 and U4 form the second-stage transducer receiving circuit, specifically a two-to-one switch, one of which must be connected to GND (level reference terminal). As can be seen from the diagram, the control signals (A_C0, A_C1) of U3 are logically coupled with the enable signal EN_2 of U2. When EN_2 is turned on (enabled), A_K0 must be energized, connecting the irrelevant signal to GND.

[0044] The control signals (B_C0, B_C1) of U4 are logically coupled with the enable signal EN_2 of U2. When EN_1 is turned on (enabled), B_K0 must be engaged to connect the irrelevant signal to GND.

[0045] After the two-stage channel switching described above, the output signal is not directly short-circuited but enters the third-stage transducer receiving circuit for another switching selection, further reducing the influence of signals between channels and improving the flexibility of signal selection. U5 is the third-stage transducer receiving circuit, specifically the third-stage channel selection switch, which is a two-to-one switch. The control signals (N_C0, N_C1) of U5 are logically coupled with the enable signals EN_1 of U1 and EN_2 of U2. When EN_1 is turned on (enabled), N_K0 is engaged and N_K1 is turned off. When EN_2 is turned on (enabled), N_K1 is engaged and N_K0 is disengaged.

[0046] Optionally, the third-stage transducer receiving circuit further includes a grounding interface for protective grounding.

[0047] The above embodiments are merely one of the implementation methods for achieving the technical solution of this utility model. The scope of protection claimed by this utility model is not limited to this embodiment, but also includes any variations, substitutions, and other implementation methods that are easily conceived by those skilled in the art within the scope of the technology disclosed in this utility model. Although embodiments of this utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this utility model. The scope of this utility model is defined by the appended claims and their equivalents.

Claims

1. A low-noise switching circuit for multi-channel ultrasonic signal reception, characterized in that, The system includes two physically isolated multi-stage transducer receiving circuits for receiving signals from two mutually excited ultrasonic sensors. Each multi-stage transducer receiving circuit includes a first-stage transducer receiving circuit and a second-stage transducer receiving circuit connected in series. The first-stage transducer receiving circuit includes several transducer receiving signal channels connected in parallel, and these channels are connected to a multiplexer switch. The second-stage transducer receiving circuit includes at least two parallel noise reduction channels, one of which is grounded, and the other is connected to the output terminal. The two noise reduction channels are connected to a two-to-one switch.

2. The low-noise switching circuit for multi-channel ultrasonic signal reception according to claim 1, characterized in that, Both the first-stage transducer receiving circuit and the second-stage transducer receiving circuit include a controller input interface and an enable coupling interface, which are used to receive a multi-select switch signal from the controller and to realize ground control coupling between the two sets of multi-stage transducer receiving circuits, respectively.

3. A low-noise switching circuit for multi-channel ultrasonic signal reception according to claim 2, characterized in that, The enable coupling interface of the first stage transducer receiving circuit of a multi-stage transducer receiving circuit is connected to the enable coupling interface circuit of the second stage transducer receiving circuit of another multi-stage transducer receiving circuit.

4. A low-noise switching circuit for multi-channel ultrasonic signal reception according to claim 1, characterized in that, It also includes a third-stage transducer receiving circuit; the third-stage transducer receiving circuit is connected to the second-stage transducer receiving circuit; the third-stage transducer receiving circuit includes two parallel output channels, and the two output channels are respectively connected to the second-stage transducer receiving circuits of two different multi-stage transducer receiving circuits.

5. A low-noise switching circuit for multi-channel ultrasonic signal reception according to claim 4, characterized in that, The third-stage transducer receiving circuit also includes a controller input interface and an output coupling interface, which are used to receive a multi-select switch signal from the controller and to realize output control coupling between the two sets of multi-stage transducer receiving circuits, respectively.

6. A low-noise switching circuit for multi-channel ultrasonic signal reception according to claim 5, characterized in that, The output coupling interface is connected to the enable coupling interface circuit of the first stage transducer receiving circuit of two different multi-stage transducer receiving circuits.

7. A low-noise switching circuit for multi-channel ultrasonic signal reception according to claim 5, characterized in that, The third-stage transducer receiving circuit also includes a grounding interface for protective grounding.

8. A low-noise switching circuit for multi-channel ultrasonic signal reception according to claim 1, characterized in that, The physical isolation is achieved by placing two sets of multi-stage transducer receiving circuits in different electronic devices.

9. A low-noise switching circuit for multi-channel ultrasonic signal reception according to claim 8, characterized in that, The isolation between the two sets of multi-stage transducer receiving circuits is better than -60dB.

10. A low-noise switching circuit for multi-channel ultrasonic signal reception according to claim 9, characterized in that, Both the multiple-choice switch and the two-choice switch are digital switches.

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