Acoustic testing system for a directional sound-emitting device

Abstract

This utility model discloses an acoustic testing system for a directional sound-emitting device, including an audio analyzer, an audio processing unit, a power amplifier, a transformer unit, a DC power supply, and a pickup unit. The audio analyzer provides audio, which is then processed as a digital audio signal by the audio processing unit. The processed audio is amplified by the power amplifier, and after exiting the power amplifier, it is amplified again by the transformer. With the DC bias provided by the DC power supply, it is then connected to the directional sound-emitting device under test. The sound emitted by the directional sound-emitting device is received by the pickup unit and returned to the audio analyzer, which displays the frequency response and distortion curves. This utility model provides a novel acoustic testing platform that enables rapid testing of the acoustic performance of directional sound-emitting devices.

Description

Technical Field

[0001] This utility model relates to the field of acoustic testing technology, and specifically to an acoustic testing system for a directional sound-emitting device. Background Technology

[0002] As a core component in fields such as acoustic sensors, the accurate measurement of the acoustic performance parameters (such as emitted sound pressure, frequency response, directivity, impedance characteristics, etc.) of ultrasonic transducers is of great significance for device optimization and system integration.

[0003] However, existing acoustic testing technologies lack specialized rapid testing platforms for ultrasonic transducers, so it is necessary to develop a new type of acoustic testing platform to enable rapid testing of the acoustic performance of ultrasonic transducers. Utility Model Content

[0004] The purpose of this invention is to provide an acoustic testing system capable of rapidly testing the acoustic performance of directional sound-emitting devices.

[0005] To achieve the above objectives, this utility model proposes an acoustic testing system for a directional sound-emitting device, comprising:

[0006] An audio analyzer is used to provide audio signals;

[0007] An audio processing unit, connected to the audio analyzer, includes an audio processor, which modulates the audio signal with an ultrasonic carrier signal to generate an ultrasonic modulation signal.

[0008] A power amplifier, connected to the audio processing unit, is used to amplify the power of the ultrasonic modulation signal.

[0009] A transformer unit, connected between the power amplifier and the audio processing unit, is used to adjust the voltage of the amplified ultrasonic modulation signal to a voltage value that matches the driving voltage of the directional sound-generating device.

[0010] A DC power supply, connected to the audio processing unit and the directional sound-emitting device under test, is used to apply a DC bias voltage to the ultrasonic modulation signal after voltage adjustment by the transformer and output it to the directional sound-emitting device to drive it to emit sound signals in a directional manner.

[0011] The pickup unit, connected to the audio analyzer, is used to collect the sound signals emitted by the directional sound-emitting device and output them to the audio analyzer.

[0012] In a preferred embodiment, the system further includes an operational amplifier for amplifying the ultrasonic modulation signal, the operational amplifier being connected between the audio processor and the power amplifier.

[0013] In a preferred embodiment, the operational amplifier and the audio processor are integrated within the audio processing unit.

[0014] In a preferred embodiment, the power amplifier is a Class AB power amplifier.

[0015] In a preferred embodiment, the transformer unit is a transformer unit with adjustable inductance.

[0016] In a preferred embodiment, the transformer unit includes multiple transformers and multiple switches, with at least one switch connected to the primary and secondary terminals of each transformer, and the corresponding transformer can be selected by switching different switches.

[0017] In a preferred embodiment, the DC power supply is a DC power supply with an adjustable DC bias voltage, and the range of the DC bias voltage is 150V~450V.

[0018] In a preferred embodiment, the directional sound-generating device is a capacitive electroacoustic transducer with a capacitance value ranging from 5nF to 180nF, and the inductance values ​​of the plurality of transformers are adapted to the capacitance value range.

[0019] In a preferred embodiment, the operational amplifier and the power amplifier amplify the ultrasonic modulation signal by 2-3 times and 4-6 times, respectively, and the transformer unit amplifies the ultrasonic modulation signal by 4-6 times after power amplification.

[0020] In a preferred embodiment, the system further includes an oscilloscope for testing electrical signal parameters, the oscilloscope being connected between the output of the audio processing unit and the directional sound-emitting device.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. This utility model provides a novel acoustic testing platform that enables rapid testing of the acoustic performance (including at least frequency response characteristics, distortion curves, and electrical signal parameters) of directional sound-generating devices.

[0023] 2. This utility model adds a transformer unit with adjustable inductance value, which can be adapted to different capacitance values ​​of the directional sound-generating device to be tested; and the DC bias voltage of the DC power supply is adjustable, which can be adjusted as needed to realize the testing of the frequency response curve and distortion curve of the directional sound-generating device under different DC voltage and AC voltage.

[0024] 3. The audio power amplifier of this utility model adopts Class AB power amplifier, which has a smaller circuit distortion curve compared with the commonly used Class D power amplifier, making the measured frequency response closer to the performance of the sound load itself. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the acoustic testing system for the directional sound-generating device of this utility model;

[0026] Figure 2 This is a schematic diagram of the transformer unit in one embodiment of the present invention.

[0027] The attached figures are labeled as follows:

[0028] 1. Audio analyzer; 2. Audio processing unit; 21. Audio processor; 22. Operational amplifier; 3. Power amplifier; 4. Transformer unit; 41. Transformer; 42. Switch; 5. DC power supply; 6. Pickup unit; 7. Directional sound generator; 8. Oscilloscope. Detailed Implementation

[0029] The specific embodiments of this utility model are described in detail below, but it should be understood that the protection scope of this utility model is not limited to the specific embodiments.

[0030] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0031] like Figure 1 As shown, the acoustic testing system for a directional sound-emitting device disclosed in this utility model includes an audio analyzer 1, an audio processing unit 2, a power amplifier 3, a transformer unit 4, a DC power supply 5, and a pickup unit 6.

[0032] The audio analyzer 1 is connected to the audio processing unit 2, specifically via a 3.5mm audio cable, and is used to provide audio signals to the audio processing unit 2.

[0033] The audio processing unit 2 specifically includes an audio processor 21, which is connected to the audio analyzer 1 and is used to modulate the audio signal with the ultrasonic carrier signal to generate an ultrasonic modulation signal. In implementation, the audio processing unit 2 can use a digital signal processing (DSP) chip, specifically a JYP-KSPT-V1.0 board; the audio processor 21 can use an ADAU1401 chip. Preferably, the audio processing unit 2 can be controlled by external simulation software SigmaStudio (a graphical development tool developed by Analog Devices) via an I2C bus. The SigmaStudio simulation software can adjust the carrier frequency and audio gain of the directional sound-emitting device and arbitrarily change the magnitude of the audio voltage. Preferably, the audio processing unit can also include an operational amplifier 22 connected to the audio processor. The operational amplifier 22 and the audio processor 21 are both integrated within the audio processing unit 2 and are used to amplify the ultrasonic modulation signal, typically by 2 to 3 times. In implementation, an OPA1632DR operational amplifier can be used.

[0034] Power amplifier 3 is connected to audio processing unit 2, specifically to the output of operational amplifier 22, and is used to amplify the ultrasonic modulation signal. Preferably, power amplifier 3 is a Class AB power amplifier, specifically an AMP50-D amplifier. Compared to commonly used Class D amplifiers, Class AB amplifiers have a smaller circuit distortion curve, making the measured frequency response closer to the performance of the sound-generating load itself. Power amplifier 3 further amplifies the ultrasonic modulation signal by 4 to 6 times, typically around 5 times. Of course, in other alternative embodiments, operational amplifier 22 in audio processing unit 2 can be omitted, that is, the ultrasonic modulation signal obtained by audio processor 21 is directly input to power amplifier 3 for power amplification.

[0035] The transformer unit 4 is connected between the power amplifier 3 and the audio processing unit 2, and is used to adjust the voltage of the amplified ultrasonic modulation signal to a voltage value that matches the driving voltage of the directional sound-generating device 7. In practice, the transformer unit 4 amplifies the voltage of the amplified ultrasonic modulation signal by 4 to 6 times.

[0036] The DC power supply 5 is connected to the audio processing unit 2 and the directional sound-emitting device 7 under test. It applies a DC bias voltage to the ultrasonic modulation signal (after voltage adjustment by the transformer unit 4) and outputs it to the directional sound-emitting device 7, driving it to emit a directional sound signal. Since the directional sound-emitting device 7 exhibits different frequency response curves under different DC biases, the DC bias is preferably adjustable. Therefore, the DC power supply 5 is an external DC power supply with an adjustable DC bias voltage, meaning its DC voltage can be arbitrarily adjusted. In practice, the DC bias voltage range is 150V~450V to accommodate directional sound-emitting devices 7 with different voltages. Specifically, the DC power supply can be a model HSPY-1000-00.

[0037] In this embodiment, the directional sound-emitting device 7 is a capacitive electroacoustic transducer, specifically an electrostatic ultrasonic transducer. During testing, the voltage of the applied audio signal needs to be pushed up to over 250 volts. Therefore, different load capacitance values ​​require different transformer inductance values. Thus, different transformer unit 4 inductance values ​​need to be matched to the capacitance values ​​of different directional sound-emitting devices 7. Therefore, the transformer unit 4 is preferably an adjustable inductance unit. In a specific embodiment, such as... Figure 2 As shown, the transformer unit 4 includes multiple transformers 41 and multiple switches 42. Each transformer 41 has at least one switch 42 connected to its primary and secondary terminals respectively. The corresponding transformer 41 is selected by switching different switches 42. For example, if 10 transformers 41 are used, the inductance value of each transformer 41 is configured using the formula F(frequency) = 1 / (2×Pi×Sqrt(L×C)), where L is the inductance value of the transformer 41, C is the capacitance value of the directional sound-emitting device 7, and F is the operating frequency value of the directional sound-emitting device 7. The capacitance value of the directional sound-emitting device 7 ranges from 5nF to 180nF. These 10 transformers 41 can cover this capacitance range, meaning they can accommodate directional sound-emitting devices 7 with different capacitance values. This allows the audio voltage to be pushed to over 200V for directional sound-emitting devices 7 of different sizes, processes, and LCR parameters. In implementation, relays can be used as switches.

[0038] The pickup unit 6 is connected to the audio analyzer 1 and is used to collect the ultrasonic modulation signal emitted by the directional sound-emitting device 7, demodulate it through the air, and output the sound signal to the audio analyzer 1. The audio analyzer 1 displays the frequency response curve and distortion curve of the directional sound-emitting device 7 in real time. In practice, the pickup unit 6 can be a microphone.

[0039] In addition, the above-mentioned test system also includes an oscilloscope 8, which is connected between the output terminal of the audio processing unit 2 and the directional sound-emitting device 7, and is used to test electrical signal parameters (such as voltage, current, etc.).

[0040] The advantages of this invention are as follows: 1. This invention provides a novel acoustic testing platform capable of rapidly testing the acoustic performance (at least including frequency response characteristics, distortion curves, and electrical signal parameters) of directional sound-generating devices. 2. This invention adds a transformer unit with adjustable inductance, which can adapt to different capacitance values ​​of the directional sound-generating device under test; and the DC bias voltage of the DC power supply is adjustable, which can be adjusted as needed to test the frequency response and distortion curves exhibited by the directional sound-generating device under different DC and AC voltages. 3. The audio power amplifier of this invention uses a Class AB amplifier, which has a smaller circuit distortion curve compared to the commonly used Class D amplifier, making the measured frequency response closer to the performance of the sound-generating load itself.

[0041] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the present invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the present invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the present invention, as well as various different choices and variations. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. An acoustic testing system for a directional sound-emitting device, characterized in that, include: An audio analyzer is used to provide audio signals; An audio processing unit, connected to the audio analyzer, includes an audio processor, which modulates the audio signal with an ultrasonic carrier signal to generate an ultrasonic modulation signal. A power amplifier, connected to the audio processing unit, is used to amplify the power of the ultrasonic modulation signal. A transformer unit, connected between the power amplifier and the audio processing unit, is used to adjust the voltage of the amplified ultrasonic modulation signal to a voltage value that matches the driving voltage of the directional sound-generating device. A DC power supply, connected to the audio processing unit and the directional sound-emitting device under test, is used to apply a DC bias voltage to the ultrasonic modulation signal after voltage adjustment by the transformer and output it to the directional sound-emitting device to drive it to emit sound signals in a directional manner. The pickup unit, connected to the audio analyzer, is used to collect the sound signals emitted by the directional sound-emitting device and output them to the audio analyzer.

2. The acoustic testing system for a directional sound-emitting device as described in claim 1, characterized in that, The system also includes an operational amplifier for amplifying the ultrasonic modulation signal, the operational amplifier being connected between the audio processor and the power amplifier.

3. The acoustic testing system for a directional sound-emitting device as described in claim 2, characterized in that, The operational amplifier and the audio processor are integrated within the audio processing unit.

4. An acoustic testing system for a directional sound-emitting device as described in any one of claims 1 to 3, characterized in that, The power amplifier is a Class AB power amplifier.

5. The acoustic testing system for a directional sound-emitting device as described in claim 1, characterized in that, The transformer unit is an adjustable inductance transformer unit.

6. The acoustic testing system for a directional sound-emitting device as described in claim 5, characterized in that, The transformer unit includes multiple transformers and multiple switches. Each transformer has at least one switch connected to its primary and secondary terminals respectively. The corresponding transformer can be selected by switching different switches.

7. The acoustic testing system for a directional sound-emitting device as described in claim 1, characterized in that, The DC power supply is a DC power supply with an adjustable DC bias voltage, and the range of the DC bias voltage is 150V~450V.

8. The acoustic testing system for a directional sound-emitting device as described in claim 6, characterized in that, The directional sound-generating device is a capacitive electroacoustic transducer with a capacitance value ranging from 5nF to 180nF, and the inductance values ​​of the multiple transformers are adapted to the capacitance value range.

9. The acoustic testing system for a directional sound-emitting device as described in claim 2, characterized in that, The operational amplifier and power amplifier amplify the ultrasonic modulation signal by 2-3 times and 4-6 times respectively, and the transformer unit amplifies the ultrasonic modulation signal by 4-6 times after power amplification.

10. The acoustic testing system for a directional sound-emitting device as described in claim 1, characterized in that, The system also includes an oscilloscope for testing electrical signal parameters, the oscilloscope being connected between the output of the audio processing unit and the directional sound-emitting device.

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