Ultrasonic detection transmission-reception system
By combining an ultrasonic transmitting circuit, an adjustable delay receiving circuit, and a gain amplification circuit, the problems of complex signal conditioning and numerous interference signals in existing technologies are solved, achieving signal gain and interference filtering effects, and improving the accuracy and stability of detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU PTC OPTICAL INSTR
- Filing Date
- 2025-05-26
- Publication Date
- 2026-06-16
AI Technical Summary
Existing ultrasonic transmitting and receiving systems have complex methods for adjusting ultrasonic signals and receive a lot of interference signals, resulting in low accuracy of detection results.
An ultrasonic transmitting circuit, an adjustable delay receiving circuit, and a gain amplification circuit are used. A monostable multivibrator and a coupling capacitor are used to filter out DC signals. Combined with amplification and attenuation circuits, signal gain adjustment and interference signal filtering are achieved.
It achieves good signal gain, good interference filtering, easy waveform signal adjustment, and clearer display, thus improving the stability and reliability of the detection results.
Smart Images
Figure CN224366193U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of ultrasound, and in particular to an ultrasonic detection transmission and reception system. Background Technology
[0002] Ultrasound is a sound wave with a frequency higher than 20 kHz. It has good directionality and strong penetrating power, and is widely used in underwater acoustics, engineering, biology and other fields. Specific applications include: using sound wave reflection, diffraction and Doppler effect to manufacture ultrasonic level gauges, ultrasonic liquid level gauges, ultrasonic flow meters, etc.; ultrasonic velocity measurement and distance measurement; taking advantage of the ability of ultrasound to penetrate opaque materials and its good directionality, it is widely used in ultrasonic flaw detection, inspection, remote control and ultrasonic imaging technology; ultrasonic cleaning, ultrasonic humidification, etc.
[0003] Ultrasonic flaw detectors primarily utilize the reflection method to obtain information about the internal characteristics of objects. The reflection method works based on the principle that ultrasound waves undergo strong reflection when passing through interfaces of tissues with different acoustic impedances. The excitation and reception of ultrasound waves are often critical components of an ultrasonic flaw detector system, significantly impacting instrument quality. Existing ultrasonic transmitting and receiving systems suffer from complex signal modulation methods and receive numerous interference signals, resulting in low accuracy of ultrasonic testing results. Utility Model Content
[0004] This invention provides an ultrasonic detection transmitting and receiving system with good signal gain, good interference signal filtering, easy waveform signal adjustment, and clearer display. The technical solution is as follows.
[0005] An ultrasonic detection transmitting and receiving system includes an ultrasonic transmitting circuit, an ultrasonic probe, an adjustable delay receiving circuit, and a gain amplification circuit. The ultrasonic transmitting circuit is connected to the ultrasonic probe. The adjustable delay receiving circuit includes a monostable multivibrator, a diode D3, and a coupling capacitor C3. The return signal from the ultrasonic probe is biased by the monostable multivibrator. The bias voltage is greater than the forward conduction voltage of the diode D3. The DC signal is filtered out by the coupling capacitor C3 and then enters the gain amplification circuit.
[0006] Furthermore, the monostable multivibrator is a 16-pin dual D flip-flop, including a first D flip-flop unit and a second D flip-flop unit, wherein the first D flip-flop unit is connected to an external capacitor Cext and an external resistor RT.
[0007] Furthermore, when the ultrasonic probe returns a signal from the first D flip-flop unit, the monostable multivibrator will jump from a stable state to a quasi-stable state. Then, the values of RT and Cext are adjusted to regulate the delay output time, allowing the monostable multivibrator to automatically return to its original stable state.
[0008] Furthermore, the gain amplification circuit includes a combination circuit for signal amplification and attenuation, wherein the attenuation circuit includes multiple attenuators and the signal amplification circuit includes multiple amplifiers.
[0009] Furthermore, the attenuation circuit includes six digitally controlled attenuators, and the signal amplification circuit includes four +12dB amplifiers, one +18dB amplifier, and one +15dB amplifier.
[0010] Furthermore, in the gain amplifier circuit, the signal passes through four +12 dB amplifiers, with a total gain of 48 dB, and then through a +18 dB amplifier, with a total gain of 66 dB. The signal then passes through a 0 to -63 dB digital step attenuator, and then through a +15 dB amplifier, with the final output range being 0 to +63 dB.
[0011] Furthermore, the attenuators in the attenuation circuit include attenuators of 16dB, 8dB, 4dB, 2dB, 1dB, and 0.5dB.
[0012] Furthermore, the ultrasonic transmitting circuit generates a high-voltage negative pulse, including an NPN transistor Q, a capacitor C, a diode D1, a diode D2, a resistor R, a resistor R0, and a switch S.
[0013] Furthermore, in the ultrasonic transmitting circuit, the base of transistor Q is connected to VCC through resistor R, the emitter is grounded, capacitor C is connected between the collector of transistor Q and ground, diode D1 is connected between capacitor C and ground, D2 is connected between capacitor C and switch S, switch S is connected between D2 and ground, and resistor R0 is connected between switch S and ground.
[0014] The ultrasonic excitation transmitting and receiving system of this invention has the following beneficial effects:
[0015] Stable excitation pulse signal: The ultrasonic transmitting circuit uses a transistor generator to produce a high-voltage discharge negative pulse, which can stably excite the piezoelectric crystal to generate ultrasonic waves, ensuring the reliability and consistency of ultrasonic wave transmission and providing a good foundation for subsequent testing.
[0016] Effective signal processing: The adjustable delay receiving circuit is a retriggered monostable multivibrator. Through the cooperation of diodes and capacitors, it can effectively process the input signal and output a fixed-width pulse after receiving the trigger signal. The retriggered characteristic makes the circuit more flexible and reliable in practical applications. Specifically, the delay receiving time length and the required receiving time length are set by the monostable multivibrator, covering the time range of the quasi-steady-state triggering to cover the time of the ultrasonic wave signal recovery. This effectively filters out useless noise signals, improves the signal-to-noise ratio, reduces noise interference, enhances signal stability, and enables the detection system to work stably in complex environments. The gain amplifier circuit, combined with the rational design and component selection of amplification, attenuation, and filtering circuits, amplifies the ultrasonic wave return signal of a few mV to an amplitude suitable for observation and analysis, ensuring the stability of the signal during transmission and processing, facilitating subsequent processing and judgment, and making the detection results more stable and reliable.
[0017] In summary, the ultrasonic excitation transmitting and receiving system of this invention obtains better signal quality. Attached Figure Description
[0018] Figure 1 This is an overall block diagram of the system of this utility model.
[0019] Figure 2 This is a schematic diagram of an ultrasonic transmitting circuit.
[0020] Figure 3 This is a schematic diagram of an adjustable delay receiver circuit.
[0021] Figure 4 This is a schematic diagram of a monostable multivibrator.
[0022] Figure 5 is a schematic diagram of the signal waveform.
[0023] Figure 6 is a schematic diagram of the variable gain circuit's range.
[0024] Figure 7 is a schematic diagram of the gain variation range of the attenuator. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0026] Reference Figure 1 , Figure 3An ultrasonic detection transmitting and receiving system includes an ultrasonic transmitting circuit, an ultrasonic probe, an adjustable delay receiving circuit, and a gain amplification circuit. The ultrasonic transmitting circuit is connected to the ultrasonic probe. The adjustable delay receiving circuit includes a monostable multivibrator, a diode D3, and a coupling capacitor C3. The monostable multivibrator is used to set the delay receiving time and adjust the required receiving time. The ultrasonic probe's return signal is biased by the monostable multivibrator, with the bias voltage being greater than the forward conduction voltage of the diode D3. The DC signal is filtered out by the coupling capacitor C3 before entering the gain amplification circuit.
[0027] Specifically, the monostable multivibrator is a 16-pin dual D flip-flop U9. The dual D flip-flop models can be selected from CD14538BM96, 74HCT123D, SN74LS123DR, etc., and include two D flip-flop units: a first D flip-flop unit and a second D flip-flop unit. The first D flip-flop unit is connected to an external capacitor Cext and an external resistor RT. Referring to Figure 4, capacitor Cext corresponds to capacitor C38, and external resistor RT corresponds to resistors R39 and R41. This circuit is used for signal shaping and timing. When a trigger signal is input to the first D flip-flop unit through pin 1, an output signal with a pulse width determined by external resistors R39 and R41 and capacitor C38 is generated and output from pin 4. The external capacitor Cext and external resistor RT are adjustable or replaceable. Currently, some pins of the second D flip-flop unit are not connected. With appropriate external components and trigger signals, a similar monostable triggering function can also be achieved.
[0028] A monostable multivibrator has one steady state and one quasi-steady state (non-steady state). When the ultrasonic probe's return signal is triggered by the input of the first D flip-flop unit, the monostable multivibrator will jump from the steady state to the quasi-steady state. After adjusting the values of RT and Cext to adjust the delay output time "T", the monostable multivibrator will automatically return to its original steady state. Referring to Figure 5, by covering the time range of the quasi-steady trigger with the ultrasonic signal recovery time, the signal can be received only during the ultrasonic reception period, filtering out all useless noise in other time periods. This can greatly reduce useless noise signals. For example, if Cext = 100000pf and RT = 40K, then the quasi-steady state time T = 0.33 × RT × Cext = 0.33 × 40 × 10000 = 13200ns = 13.2μm. Figure 5 The four waveforms A, B, C, and D in the image are compared. Figure 3Analyzing the four positions A, B, C, and D in the waveform analysis, waveform A is the original ultrasonic return signal, containing noise. Waveforms B and C show the processed state of the signal; waveform B is quasi-steady-state, waveform C is steady-state, and waveform D is a cleaner signal, having removed most of the noise—the desired signal. The input signal A passes through a diode D3 and a coupling capacitor C3, then enters a retriggable monostable multivibrator, ultimately outputting D. Diode D3 prevents reverse current, and coupling capacitor C3 filters or stabilizes the voltage, performing preliminary signal processing. The monostable multivibrator then further processes the signal, generating a timing signal, shaping the input signal, and processing the noisy ultrasonic signal to produce a stable and clean output signal, which then enters the gain amplifier circuit.
[0029] Reference Figure 4 The pin connections of the dual D flip-flop U9 are as follows:
[0030] Pin 16 is connected to a +5V power supply (VCC) to provide the operating voltage for the chip.
[0031] Pins 8 and 14 are grounded (GND) to provide a reference potential for the circuit.
[0032] Pin 1 is connected to ground (GND).
[0033] Pin 2 is a 1B pin, which is connected to the trigger signal input of the ultrasonic return.
[0034] Pin 3 is connected to +5V as the reset signal (#1CR) for the first D flip-flop unit.
[0035] Pin 4 is the output pin (#1Q) of the first D flip-flop unit, used to output the signal after monostable triggering.
[0036] Pins 5 and 12 are not connected (marked with an X in the diagram to indicate they are not connected), and are the output pins (#2Q and 2Q) of the second D flip-flop unit, respectively.
[0037] Pins 6 and 8 are connected to ground (GND), which are the 2CEXT and GND pins, respectively.
[0038] Pin 7 is the external resistor and capacitor pin (2REXT / CEXT) of the second D flip-flop, and no external components are connected in the figure.
[0039] Pin 9 (pin 2A) is connected to the voltage divider circuit consisting of R41 and R39.
[0040] Pins 10 and 11 are connected to ground (GND), which are pins 2B and #2CLR respectively.
[0041] Pin 13 is another output pin (1Q) of the first D flip-flop unit.
[0042] Pin 14 is grounded and works with pin 15 to set the monostable parameters.
[0043] Pin 15 is the external resistor and capacitor pin (1REXT / CEXT) of the first D flip-flop unit, and the monostable timing parameters are set by the external resistor R39 and capacitor C38.
[0044] Furthermore, combined with Figures 6-7 The gain amplifier circuit includes a combination of signal amplification and attenuation circuits. The attenuation circuit includes multiple attenuators, and the signal amplification circuit includes multiple amplifiers. In this embodiment, the attenuation circuit includes six digitally controlled attenuators, with attenuators of 16dB, 8dB, 4dB, 2dB, 1dB, and 0.5dB respectively. These attenuators are connected by switches, and different attenuation combinations are selected through digital serial control. This allows for adjustment of the total attenuation as needed, achieving precise signal control. The signal amplification circuit includes four +12dB amplifiers, one +18dB amplifier, and one +15dB amplifier. In the gain amplifier circuit, the signal passes through four +12dB amplifiers, achieving a total gain of 48dB. Then, it passes through a +18dB amplifier, reaching a total gain of 66dB. The signal then passes through a 0-63dB digital step attenuator and a +15dB amplifier, resulting in a final output range of 0-63dB. The entire system, through the combination of multiple amplifiers and attenuators, can both amplify the signal and precisely control the signal strength through attenuators, thus achieving flexible signal control.
[0045] In addition, the ultrasonic transmitting circuit generates high-voltage negative pulses, including an NPN transistor Q, a capacitor C, diodes D1 and D2, resistors R and R0, and a switch S. In the ultrasonic transmitting circuit, the base of transistor Q is connected to VCC through resistor R, and the emitter is grounded. Capacitor C is connected between the collector of transistor Q and ground to store charge. Diode D1 is connected between capacitor C and ground, and D2 is connected between capacitor C and switch S to control the current direction. Switch S is connected between D2 and ground to trigger the action. Resistor R0 is connected between switch S and ground to limit current and protect other components in the circuit. By controlling the opening and closing of switch S, these pulses can be generated periodically, thereby emitting ultrasonic signals. Thus, the circuit generates high-voltage negative pulses and emits ultrasonic signals through the charging and discharging process of capacitor C and the conduction and cutoff of transistor Q. Diodes D1 and D2 ensure unidirectional current flow, and resistor R0 provides current limiting protection. Specifically, when switch S is closed, current flows to ground through D2, and capacitor C begins to discharge. The base of transistor Q is connected to VCC through resistor R. When capacitor C discharges, a negative pulse is generated at the base, temporarily turning off transistor Q. When transistor Q is off, the current between the collector and emitter is interrupted, and capacitor C discharges to ground through D1, generating a high-voltage negative pulse. This high-voltage negative pulse is the signal required for ultrasonic wave transmission. The high-voltage negative pulse excites the piezoelectric crystal of the ultrasonic probe, generating ultrasonic waves to scan the product to be inspected. The reflected ultrasonic echo signal is then shaped, filtered, and denoised by the adjustable delay receiving circuit before being sent to the gain amplifier circuit to obtain a better ultrasonic signal.
[0046] Furthermore, the above embodiments are only used to illustrate the present utility model and are not intended to limit the technical solutions described in the present utility model. The understanding of this specification should be based on those skilled in the art. Although the present utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications or equivalent substitutions to the present utility model. All technical solutions and improvements that do not depart from the spirit and scope of the present utility model should be covered within the scope of the claims of the present utility model.
Claims
1. An ultrasonic detection transmitting and receiving system, characterized in that: The device includes an ultrasonic transmitting circuit, an ultrasonic probe, an adjustable delay receiving circuit, and a gain amplification circuit. The ultrasonic transmitting circuit is connected to the ultrasonic probe. The adjustable delay receiving circuit includes a monostable multivibrator, a diode D3, and a coupling capacitor C3. The return signal from the ultrasonic probe is biased by the monostable multivibrator. The bias voltage is greater than the forward conduction voltage of the diode D3. The DC signal is filtered out by the coupling capacitor C3 and then enters the gain amplification circuit.
2. The ultrasonic detection transmitting and receiving system according to claim 1, characterized in that: The monostable multivibrator is a 16-pin dual D flip-flop, including a first D flip-flop unit and a second D flip-flop unit. The first D flip-flop unit is connected to an external capacitor Cext and an external resistor RT.
3. The ultrasonic detection transmitting and receiving system according to claim 2, characterized in that: When the ultrasonic probe returns a signal from the first D flip-flop unit, the monostable multivibrator will jump from a stable state to a quasi-stable state. Then, the values of RT and Cext are adjusted to regulate the delay output time, allowing the monostable multivibrator to automatically return to its original stable state.
4. The ultrasonic detection transmitting and receiving system according to claim 1, characterized in that: The gain amplifier circuit includes a combination circuit for signal amplification and attenuation, wherein the attenuation circuit includes multiple attenuators and the signal amplification circuit includes multiple amplifiers.
5. The ultrasonic detection transmitting and receiving system according to claim 4, characterized in that: The attenuation circuit includes six digitally controlled attenuators, and the signal amplification circuit includes four +12 dB amplifiers, one +18 dB amplifier, and one +15 dB amplifier.
6. The ultrasonic detection transmitting and receiving system according to claim 5, characterized in that: In the gain amplifier circuit, the signal passes through four +12 dB amplifiers, with a total gain of 48 dB. Then it passes through a +18 dB amplifier, bringing the total gain to 66 dB. The signal then passes through a 0 to -63 dB digital step attenuator, and then through a +15 dB amplifier, with the final output range being 0 to +63 dB.
7. The ultrasonic detection transmitting and receiving system according to claim 5 or 6, characterized in that: The attenuators in the attenuation circuit include attenuators of 16dB, 8dB, 4dB, 2dB, 1dB and 0.5dB.
8. The ultrasonic detection transmitting and receiving system according to claim 1, characterized in that: The ultrasonic transmitting circuit generates a high-voltage negative pulse and includes an NPN transistor Q, a capacitor C, a diode D1, a diode D2, a resistor R, a resistor R0, and a switch S.
9. The ultrasonic detection transmitting and receiving system according to claim 8, characterized in that: In the ultrasonic transmitting circuit, the base of transistor Q is connected to VCC through resistor R, the emitter is grounded, capacitor C is connected between the collector of transistor Q and ground, diode D1 is connected between capacitor C and ground, D2 is connected between capacitor C and switch S, switch S is connected between D2 and ground, and resistor R0 is connected between switch S and ground.