阅读说明：本技术 一种无延时开关电路、开关及超声波损伤诊断和检测设备 (Non-delay switch circuit, switch and ultrasonic damage diagnosis and detection equipment ) 是由 王奕首 林霆威 邹丽 孙哲 于 2020-12-09 设计创作，主要内容包括：本发明涉及开关电路技术领域,特别涉及一种无延时开关电路、开关及超声波损伤诊断和检测设备,包括压电晶片,所述压电晶片上设置有电路；所述电路包括用于接收激励信号的激励端以及采集传感器信号的接收端；所述激励端通过第一组背靠背二极管与第一桥路的输入端连接；所述第一桥路的输出端与地线连接,其余两端反向加载电压；所述接收端不仅与传感器电性连接,还通过第二组背靠背二极管与第一组背靠背二极管的输出端连接；所述第二组背靠背二极管的输出端与限流单元的输入端连接；所述限流单元的输出端与下级电路连接。本发明提供的无延时开关电路可以实现压电晶片对信号的自发自收,并且可减少压电晶片信号之间的相互干扰,极大简化了整体结构。(The invention relates to the technical field of switch circuits, in particular to a non-delay switch circuit, a switch and ultrasonic damage diagnosis and detection equipment, which comprises a piezoelectric wafer, wherein a circuit is arranged on the piezoelectric wafer; the circuit comprises an excitation end for receiving an excitation signal and a receiving end for acquiring a sensor signal; the excitation end is connected with the input end of the first bridge circuit through a first group of back-to-back diodes; the output end of the first bridge circuit is connected with the ground wire, and voltages are reversely loaded at the other two ends; the receiving end is electrically connected with the sensor and is also connected with the output end of the first group of back-to-back diodes through the second group of back-to-back diodes; the output end of the second group of back-to-back diodes is connected with the input end of the current limiting unit; and the output end of the current limiting unit is connected with the lower-level circuit. The non-delay switch circuit provided by the invention can realize the spontaneous receiving and spontaneous receiving of the piezoelectric wafers to the signals, can reduce the mutual interference among the piezoelectric wafers, and greatly simplifies the whole structure.)

1. A non-delay switch circuit comprises a piezoelectric wafer, and is characterized in that: a circuit is arranged on the piezoelectric wafer; the circuit comprises an excitation end for receiving an excitation signal and a receiving end for acquiring a sensor signal; the excitation end is connected with an input end junction of a first bridge circuit (20) through a first group of back-to-back diodes (10); the other output end which is symmetrical to the input end of the first bridge circuit (20) is connected with a ground wire, and the other two symmetrical end joints are reversely loaded with voltage;

the receiving end is electrically connected with the sensor and is also connected with the output end of the first group of back-to-back diodes (10) through a second group of back-to-back diodes (30); the output end of the second group of back-to-back diodes (30) is connected with the input end of the current limiting unit (40); and the output end of the current limiting unit (40) is connected with a lower-stage circuit.

2. The non-delay switching circuit of claim 1, wherein: the first bridge (20) is reverse loaded with a voltage of + -15V.

3. The non-delay switching circuit of claim 1, wherein: the output end of the current limiting unit (40) is further connected with a third group of back-to-back diodes (50), and the output end of the third group of back-to-back diodes (50) is connected with a ground wire.

4. A non-delay switching circuit according to claim 3, wherein: the first group of back-to-back diodes (10), the second group of back-to-back diodes (30) and the third group of back-to-back diodes (50) are IN40004 IN model number.

5. The non-delay switching circuit of claim 1, wherein: the current limiting unit (40) is a second bridge circuit composed of four diodes.

6. The non-delay switching circuit of claim 5, wherein: the other two symmetrical ends of the first bridge circuit (20) and/or the second bridge circuit are respectively connected with a resistor in series.

7. The non-delay switching circuit of claim 5, wherein: the other two symmetrical ends of the second bridge circuit are oppositely loaded with voltage.

8. A non-delay switch, characterized by: use of a non-delay switching circuit as claimed in any one of claims 1 to 7.

9. An ultrasonic damage diagnosis apparatus characterized in that: a non-delay switch as claimed in claim 8.

10. An ultrasonic inspection apparatus characterized by: use of a non-delay switching circuit as claimed in any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of switch circuits, in particular to a non-delay switch circuit, a switch and ultrasonic damage diagnosis and detection equipment.

Background

The piezoelectric material is a novel intelligent material, and after the piezoelectric material is found to have piezoelectric effect from the curie brother in 1880, the piezoelectric material is rapidly developed along with the continuous improvement of the scientific production process of the material, and the application field of the piezoelectric material is more and more extensive. The piezoelectric material has a piezoelectric effect, namely, an effect of mutual conversion of electric energy and mechanical energy, so that an electric signal is converted into a guided wave signal for detection, and an echo signal of the guided wave is converted into an electric signal for analysis, so that the piezoelectric crystal is also widely applied to the field of sound waves.

The patent name of CN201020678856.1 discloses a vacuum degree detection device of a vacuum heat insulation plate, and the publication date is 2011, 11, 09, and discloses a vacuum degree detection device which is provided with a signal sending device and a signal receiving and processing device; the signal sending device is provided with a vacuum sensor, a built-in single chip microcomputer, a built-in piezoelectric crystal and an electromagnetic relay switch; the signal receiving and processing device is provided with an external piezoelectric crystal, an amplifying circuit, a filter circuit, a following circuit, an external singlechip and a display. The detection and transmission of the vacuum degree of the inner part of the vacuum heat insulation plate are realized. The work of the built-in single chip microcomputer is controlled by the magnetic switch in combination with the single chip microcomputer and a peripheral signal processing circuit, and real-time accurate detection and identification of the numerical value of the vacuum degree of the built-in vacuum heat insulation plate are achieved. The standby state of the built-in singlechip is not power-consuming, and the operation is simple, convenient and safe.

In order to realize the sending and receiving of the piezoelectric wafers to signals, one piezoelectric wafer is adopted as excitation, the other piezoelectric wafer is adopted as receiving, the overall structure is complex, the system building is redundant, a large number of cables can be generated, and the detection and the line investigation are both unfavorable. And also employs a relay as a switch, an inherently noisy device whose switch closure and contact bounce can produce high amplitude stray pulses that can damage very sensitive receiving electronics and produce unreliable data.

Disclosure of Invention

In order to solve the technical problems that the piezoelectric wafer cannot be automatically sent and received and has a complex structure in the application, the invention provides a non-delay switch circuit, which comprises a piezoelectric wafer, wherein a circuit is arranged on the piezoelectric wafer; the circuit comprises an excitation end for receiving an excitation signal and a receiving end for acquiring a sensor signal; the excitation end is connected with an input end junction of the first bridge circuit through a first group of back-to-back diodes; the other output end which is symmetrical to the input end of the first bridge circuit is connected with a grounding wire, and the other two symmetrical end contacts are reversely loaded with voltage; the receiving end is electrically connected with the sensor and is also connected with the output end of the first group of back-to-back diodes through the second group of back-to-back diodes; the output end of the second group of back-to-back diodes is connected with the input end of the current limiting unit; and the output end of the current limiting unit is connected with the lower-level circuit.

On the basis of the technical scheme, the first bridge circuit is loaded with +/-15V voltage in a reverse direction.

On the basis of the above technical scheme, further, the output end of the current limiting unit is further connected with a third group of back-to-back diodes, and the output end of the third group of back-to-back diodes is connected with a ground wire.

On the basis of the above technical solution, further, the model of the first group of back-to-back diodes, the second group of back-to-back diodes, and the third group of back-to-back diodes is IN 40004.

On the basis of the technical scheme, the current limiting unit is a second bridge circuit consisting of four diodes.

On the basis of the technical scheme, the other two symmetrical ends of the first bridge circuit and/or the second bridge circuit are respectively connected with a resistor in series.

On the basis of the technical scheme, the other two symmetrical ends of the second bridge circuit are reversely loaded with voltage.

The invention also provides a non-delay switch, which adopts the non-delay switch circuit.

The invention also provides ultrasonic damage diagnosis equipment which adopts the non-delay switch.

The invention also provides ultrasonic detection equipment which adopts the non-delay switch circuit.

Compared with the prior art, the non-delay switch circuit provided by the invention has the following advantages: the excitation end and the receiving end are arranged on the same piezoelectric wafer, so that the piezoelectric wafer can realize the spontaneous and self-receiving of signals, a plurality of unnecessary circuit structures and the number of sensors are reduced, and the whole structure is simplified. The circuit can reduce the mutual interference among the signals of the piezoelectric wafers while realizing the self-sending and self-receiving of the piezoelectric wafers, thereby greatly optimizing the performance of the non-delay switch.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a circuit diagram of a non-delay switch circuit provided in the present invention;

FIG. 2 shows the SNR change of the signal collected before and after the external circuit of the non-delay switch;

FIG. 3 is a layout diagram of an ultrasonic damage diagnosis apparatus using a prior art non-delay switch;

fig. 4 is a layout diagram of an ultrasonic damage diagnosis device using the non-delay switch provided by the invention.

Reference numerals:

10 first set of back-to-back diodes 20 first bridge 30 second set of back-to-back diodes

40 current limiting unit 50 third set of back-to-back diodes

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a non-delay switch circuit, which comprises a piezoelectric wafer, wherein a circuit is arranged on the piezoelectric wafer; the circuit comprises an excitation end for receiving an excitation signal and a receiving end for acquiring a sensor signal; the excitation end is connected with the input end junction of the first bridge circuit 20 through a first group of back-to-back diodes 10; the other output end which is symmetrical with the input end of the first bridge circuit 20 is connected with a ground wire, and the other two symmetrical end joints are reversely loaded with voltage; the receiving end is electrically connected with the sensor and is also connected with the output end of the first group of back-to-back diodes 10 through the second group of back-to-back diodes 30; the output end of the second group of back-to-back diodes 30 is connected with the input end of the current limiting unit 40; the output end of the current limiting unit 40 is connected with the lower stage circuit.

In specific implementation, as shown in fig. 1, a circuit is provided on the piezoelectric wafer; the circuit comprises an excitation end for receiving an excitation signal and a receiving end for acquiring a sensor signal; the excitation end and the receiving end are in signal connection with the host system at the upper stage, and the host system is controlled by the upper computer so as to control the excitation end and the receiving end to transmit signals. The excitation end is connected with the input end junction of the first bridge circuit 20 through a first group of back-to-back diodes 10; the back-to-back diodes are two diodes connected in parallel in reverse direction to perform the amplitude limiting function on the signal, and the first group of back-to-back diodes 10 can isolate low-level noise generated by the excitation signal by using high impedance. The other symmetrical output end of the first bridge circuit 20 is connected to ground, and the other two ends are loaded with reverse voltage, so that the bridge circuit can be reversely biased to block current by the reverse voltage, wherein the first bridge circuit 20 is formed by connecting two diodes in series in the same direction and then in parallel in the reverse direction, as shown in fig. 1. The receiving end is electrically connected with the sensor and is also connected with the output end of the first group of back-to-back diodes 10 through the second group of back-to-back diodes 30; the output end of the second group of back-to-back diodes 30 is connected with the input end of the current limiting unit 40; the output end of the current limiting unit 40 is connected with a lower circuit; wherein the current limiting unit 40 functions to limit the current at the sensor terminal so that only a small portion of the current is passed to the next stage circuit.

The specific working principle is that the excitation signal passes through the first group of back-to-back diodes 10 from the excitation end and then flows to the first bridge circuit 20, and the first bridge circuit is forward biased, so that the low-voltage noise signal at the excitation end is transmitted to the ground wire. Therefore, the circuit can isolate the devices generating the excitation signals, such as a power amplifier and the like, during signal receiving, so that mutual interference between the signals is avoided. When the excitation terminal generates a signal larger than a certain value, the first bridge circuit 20 is reverse biased, and the signal is transmitted to the sensor terminal through the second set of back-to-back diodes 30, and only a small part of the current is transmitted to the next stage circuit because the sensor terminal is connected to the current limiting unit 40. When the signal generated by the excitation end is smaller than a certain value, the first group of back-to-back diodes 10 and the second group of back-to-back diodes 30 are both open, so that the signal received back from the sensor end can be collected by the receiving end, and the voltage signal can also be transmitted to the next stage circuit through the current limiting unit 40.

According to the non-delay switch circuit provided by the invention, the excitation end and the receiving end are arranged on the same piezoelectric wafer, so that the self-sending and self-receiving of signals by the piezoelectric wafer can be realized, a plurality of unnecessary circuit structures and the number of sensors are reduced, and the whole structure is simplified. The circuit can reduce the mutual interference among the signals of the piezoelectric wafers while realizing the self-sending and self-receiving of the piezoelectric wafers, thereby greatly optimizing the performance of the time delay switch. Meanwhile, the circuit is also suitable for being connected with any sensor with the same structure of the excitation end and the receiving end.

Preferably, the first bridge 20 is reverse loaded with a voltage of ± 15V.

Preferably, the output end of the current limiting unit 40 is further connected to a third group of back-to-back diodes 50, and the output end of the third group of back-to-back diodes 50 is connected to the ground.

In specific implementation, the output end of the current limiting unit 40 is further connected to a third group of back-to-back diodes 50, and the output end of the third group of back-to-back diodes 50 is connected to the ground line. The third set of back-to-back diodes 50 is used to limit the leakage signal of the lower circuit to a sufficiently small level, so that the circuit is not sufficiently affected by the signal of the lower circuit, and the two circuits can work independently without interfering with each other.

Preferably, the first, second and third groups of back-to-back diodes 10, 30 and 50 are IN 40004.

IN specific implementation, the first, second, and third sets of back-to-back diodes 10, 30, and 50 can be rectifier diodes, but are not limited thereto, and the model thereof can be IN 40004.

Preferably, the current limiting unit 40 is a second bridge circuit composed of four diodes.

In an implementation, the current limiting unit 40 is a second bridge circuit composed of four diodes. The four diodes are connected in series in the same direction and then in parallel in the reverse direction. When the diode is forward biased, the current conducts. When the diode is reverse biased, only a small portion of the current is passed to the next stage of circuitry.

Preferably, the other two symmetrical ends of the first bridge 20 and/or the second bridge are each connected in series with a resistor.

In practical implementation, the other two symmetric ends of the first bridge circuit 20 and/or the second bridge circuit are respectively connected in series with a resistor, and the resistance value of the resistor can be selected according to requirements, for example, a very low resistance value can be selected so that most of signals transmitted back by the sensor end can be transmitted to a next stage circuit, or a very large resistance value can be selected so that signals of the sensor are rarely transmitted to a next stage circuit.

Preferably, the other two symmetric ends of the second bridge circuit are oppositely loaded with voltage.

In specific implementation, the other two symmetrical ends of the second bridge circuit are reversely loaded with voltage, so that the bridge circuit can reversely bias to block current when receiving a signal larger than a certain value.

The invention also provides a non-delay switch, which adopts the non-delay switch circuit.

In specific implementation, as shown in fig. 2, the change-over switch using the non-delay switch circuit is connected between the experimental body and the signal generator, and the feasibility of the change-over switch is verified through an experiment using a length-extension type piezoelectric wafer, as shown in fig. 2, the signal-to-noise ratio of the signals collected before and after the external circuit changes. Wherein the left graph of fig. 2 is the signal-to-noise ratio change before the arrangement of the non-delay switch, and the right graph is the signal-to-noise ratio change after the arrangement of the non-delay switch. As can be seen from the figure, the signal-to-noise ratio is greatly changed, and the high signal-to-noise ratio area is concentrated at a high gain position and is close to a direct acquisition result. In addition, within the range of a sampling interval (namely 50-120kHz and 35-45dB), the signal-to-noise ratio is kept stable and can basically reach about 50 dB. The above results prove that the circuit has small influence on signal acquisition, which shows that the circuit greatly simplifies the layout of the sensing array under the condition of small change to the original signal, and is beneficial to improving and optimizing sensing. On the other hand, the switch can also be applied to other acoustic equipment adopting a transducer structure, so that the requirements of high reliability and low failure rate are met.

The invention also provides ultrasonic damage diagnosis equipment which adopts the non-delay switch.

In practical implementation, as shown in fig. 3-4, fig. 3 shows a device that does not use the above-mentioned delay-free switch, and uses one piezoelectric wafer as an excitation and the other as a reception, and the overall structure is complex. And the number of sensors needs to be arranged more. Fig. 4 is an ultrasonic damage diagnosis device using the non-delay switch, and it can be seen that the number of sensors can be effectively optimized to half of the original number by the self-sending and self-receiving of a single piezoelectric wafer using the non-delay switch.

The invention also provides ultrasonic detection equipment which adopts the non-delay switch circuit.

In specific implementation, by adopting the ultrasonic detection equipment without the delay switch circuit, the system can be automatically switched from the excitation mode to the receiving mode without using a relay, and mutual interference among signals of the piezoelectric wafers can be reduced.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.