Vehicle-mounted audio amplifier performance detection system and method

Abstract

The invention provides a vehicle-mounted audio amplifier performance detection system and a measurement method, and relates to the technical field of electronic measurement. The system comprises a signal input and output differential circuit, a first analog-to-digital conversion circuit, a microphone detection circuit, a second analog-to-digital conversion circuit, a temperature detection circuit, a current acquisition and amplification circuit, an MCU main chip circuit and an external display part circuit. The signal input and output differential circuit is used for accessing front-stage input and rear-stage output audio analog signals of the amplifier to be tested and carrying out noise reduction and sampling processing; the microphone detection circuit processes an audio signal acquired by an external microphone; the temperature detection circuit obtains a temperature analog signal; the current acquisition and amplification circuit processes the current signal. After analog-to-digital conversion is carried out on each circuit, the MCU main chip carries out centralized processing to obtain electrical parameters, and the electrical parameters are displayed on an external part. According to the system, through integration of multiple signal conditioning channels and high-precision analog-to-digital conversion, synchronous, rapid and accurate measurement is realized.

Description

Technical Field

[0001] This invention relates to the field of electronic measurement technology, and specifically to a system and method for testing the performance of an in-vehicle audio amplifier. Background Technology

[0002] The in-vehicle audio amplifier is a core component of a car audio system, and its performance directly affects the final sound quality. To ensure product quality, manufacturers must conduct comprehensive performance testing on in-vehicle audio amplifiers before they leave the factory. Traditional testing methods mainly rely on multiple discrete testing instruments, such as using a digital multimeter to measure voltage and current, using an audio analyzer to measure frequency response and distortion, using a sound level meter to measure sound pressure, and using a thermometer to measure temperature.

[0003] This testing system, composed of multiple discrete instruments, has significant drawbacks: First, the system is complex to set up, with cumbersome connections between instruments, consuming a large amount of workspace; second, during the testing process, multiple instruments need to be powered and operated separately, resulting in cumbersome procedures, low testing efficiency, and hindering rapid, batch testing on the production line; third, data synchronization and integration between different instruments are also difficult, making it hard to achieve a comprehensive and integrated evaluation of the performance of the vehicle audio amplifier. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the existing technology is difficult to achieve a comprehensive and integrated evaluation of the performance of vehicle audio amplifiers. In order to overcome the above-mentioned defects of the existing technology, the present invention provides a vehicle audio amplifier performance testing system and method.

[0005] This invention provides a vehicle-mounted audio amplifier performance testing system, comprising: The signal input-output differential circuit is used to receive the audio analog signals from the preamp input and the postamp output of the vehicle audio amplifier under test, respectively, and to perform noise reduction and sampling detection processing on the signals. The first analog-to-digital converter circuit is electrically connected to the signal input-output differential circuit and is used to convert the processed audio analog signal into an audio digital signal. The microphone detection circuit is used to receive and amplify the audio signals collected by the external microphone. The second analog-to-digital converter circuit is electrically connected to the microphone detection circuit and is used to convert the processed microphone audio signal into an audio digital signal. Temperature detection circuit, used to receive signals from NTC resistor or external temperature probe to obtain temperature analog signals; The current acquisition and amplification circuit is used to acquire the current signal from the external current clamp and amplify it. The MCU main chip circuit is electrically connected to the first analog-to-digital conversion circuit, the second analog-to-digital conversion circuit, the temperature detection circuit, and the current acquisition and amplification circuit, respectively, to receive various digital or analog signals and process them to obtain sound pressure, temperature, frequency response, distortion, voltage, and current parameters. The external display circuit is electrically connected to the MCU main chip circuit and is used to receive and display various parameters processed by the MCU main chip circuit.

[0006] Compared with existing technologies, the vehicle-mounted audio amplifier performance testing system disclosed in this application has the following advantages: By integrating multiple dedicated signal conditioning channels such as signal input / output differential circuits, microphone detection circuits, temperature detection circuits, and current acquisition and amplification circuits, and in conjunction with a high-precision analog-to-digital converter, the system is centrally processed and calculated by a unified MCU main chip, realizing synchronous, rapid, and accurate measurement of key performance parameters of the amplifier. This completely changes the predicament of traditional testing, which involves scattered equipment, cumbersome operation, and asynchronous data, greatly improving testing efficiency and the accuracy of results. It is especially suitable for rapid on-site diagnosis and comprehensive performance evaluation in vehicle environments.

[0007] In one possible implementation, the signal input / output differential circuit includes eight differential circuits, wherein the input terminals of four of the differential circuits are electrically connected to the four audio input channels of the audio amplifier under test, and the input terminals of the other four differential circuits are electrically connected to the four audio output channels of the audio amplifier under test.

[0008] Compared with existing technologies, by designing eight independent differential circuits, which are respectively connected to the four input channels and four output channels of the vehicle audio amplifier, the system achieves full-channel synchronous and parallel testing capability for multi-channel audio systems. This not only significantly improves testing efficiency and avoids the cumbersome operation of repeatedly switching channels in traditional methods, but also ensures that the input and output signals are compared on the same time reference. This provides a reliable guarantee for accurately analyzing key performance parameters of the amplifier, such as gain, frequency response, distortion, and channel consistency, and is particularly suitable for the comprehensive testing needs of current mainstream multi-channel vehicle audio systems.

[0009] In one possible implementation, the microphone detection circuit includes an amplifier U11; The positive input terminal of amplifier U11 is electrically connected to the positive terminal of the microphone via capacitor C35, and the negative terminal of the microphone is grounded. The positive input terminal of amplifier U11 is also grounded via resistor R57. Furthermore, the positive input terminal of amplifier U11 is electrically connected to the first terminal of capacitor C33 via resistor R51, and the second terminal of capacitor C33 is grounded. The positive terminal of the microphone is electrically connected to the first terminal of capacitor C33 via resistor R52, and the first terminal of capacitor C33 is electrically connected to the power supply via resistor FB5. The negative input terminal of amplifier U11 is grounded via resistor R59. The negative input terminal of amplifier U11 is also electrically connected to the output terminal of amplifier U11 via resistor R56. The output terminal of amplifier U11 is electrically connected to the second analog-to-digital converter circuit via series resistors R53 and R50. A voltage regulator circuit is connected in parallel across the resistor R50. The voltage regulator circuit includes a capacitor C32, a resistor R48, a resistor R49, and a Zener diode D4. The connection point of the resistors R53 and R50 is electrically connected to the negative terminal of the Zener diode D4. The positive terminal of the Zener diode D4 is connected in series with the resistor R49, the resistor R48, and the capacitor C32 and electrically connected to the other end of the resistor R50.

[0010] Compared with existing technologies, by constructing an amplification structure with bias and feedback using a high-precision amplifier U11, and combining it with a power supply filtering and signal conditioning network composed of capacitor C33 and resistors R51 / R52 / FB5, the anti-interference capability and signal-to-noise ratio of the microphone signal are effectively improved. In particular, an innovative parallel voltage regulator circuit composed of Zener diode D4 and resistors and capacitors is introduced at the output end, which can accurately limit the voltage amplitude sent to the subsequent ADC. This can prevent signal overshoot from damaging sensitive devices and ensure the dynamic range and linearity of the sampled signal under different sound pressure environments, thus laying a reliable hardware foundation for realizing high-precision sound pressure measurement and FFT spectrum analysis.

[0011] In one possible implementation, the temperature detection circuit includes an NTC detection circuit for detecting the temperature of the internal power amplifier board and an external temperature probe detection circuit for detecting the temperature of the external power amplifier heatsink or speaker. The NTC detection circuit includes resistors NTC1 and NTC2. One end of resistor NTC1 is grounded, and the other end of resistor NTC1 is electrically connected to the power supply through resistor R26. A capacitor C12 is connected in parallel across resistor NTC1, and the connection point between resistor NTC1 and resistor R26 is electrically connected to the MCU main chip circuit. One end of resistor NTC2 is grounded, and the other end of resistor NTC2 is electrically connected to the power supply through resistor R27. A capacitor C13 is connected in parallel across resistor NTC2, and the connection point between resistor NTC1 and resistor R27 is electrically connected to the MCU main chip circuit. The external temperature probe detection circuit includes an external temperature probe, the negative terminal of which is grounded, the positive terminal of which is electrically connected to the main chip circuit through a resistor R29, one end of which is electrically connected to the main chip circuit through a capacitor C14, a bidirectional trigger diode E1 connected in parallel across the two ends of the external temperature probe, and the positive terminal of which is electrically connected to the power supply through a resistor R28.

[0012] Compared with existing technologies, this system adopts a composite detection design that combines internal and external components. Internally, two independent NTC detection circuits (NTC1 and NTC2) perform multi-point synchronous temperature monitoring of key locations on the power amplifier board, ensuring the comprehensiveness and reliability of internal temperature data. Externally, a dedicated temperature probe detection circuit is used, and a bidirectional trigger diode E1 is innovatively introduced as the core overvoltage protection component. This effectively suppresses static electricity or surge impacts that may be introduced due to long-distance connections to external probes. Thus, while achieving accurate monitoring of the temperature of external heat sinks or speakers, the system greatly improves the durability and anti-interference capability of the entire detection system in complex automotive electrical environments.

[0013] In one possible implementation, the current acquisition and amplification circuit includes a high-current detection circuit for detecting large currents and a low-current detection circuit for detecting small currents. The input terminal of the high current detection circuit is electrically connected to the input terminal of the external current clamp, and the output terminal of the high current detection circuit is electrically connected to the MCU main chip circuit. The input terminal of the low current detection circuit is electrically connected to the output terminal of the high current detection circuit, and the output terminal of the low current detection circuit is electrically connected to the MCU main chip circuit.

[0014] Compared with existing technologies, by adopting a dual-channel collaborative detection architecture with large and small currents, seamless and accurate measurement of the wide dynamic range current of the vehicle audio amplifier is achieved. The small current detection channel cleverly obtains the signal from the output of the front-end large current channel and performs secondary amplification processing, enabling it to accurately capture the milliampere-level standby static current. This allows for high-precision acquisition of both large and small currents simultaneously without the need for range switching. This eliminates the data interruption problem caused by range switching in traditional detection and significantly improves the efficiency and accuracy of current measurement, perfectly adapting to the full-condition testing needs of vehicle audio systems from standby to full-load operation.

[0015] In one possible implementation, the external display circuit is an LCD screen for displaying parameter information processed by the MCU main chip circuit, and the LCD screen is electrically connected to the MCU main chip circuit.

[0016] Compared with existing technologies, by using an LCD display as an external display unit, the multi-dimensional parameters (such as sound pressure, temperature, frequency response, voltage and current) processed by the MCU main chip can be presented in a high-contrast and visual manner. It not only supports real-time display of various data formats such as waveforms, spectrum, and values, but also provides on-site technicians with an intuitive human-machine interface, which greatly facilitates the rapid reading and comprehensive analysis of various performance indicators of the vehicle audio amplifier, and effectively improves the efficiency of testing and the accuracy of interpretation.

[0017] In one possible implementation, the MCU main chip circuit is electrically connected to an RS-485 communication circuit for providing data transmission and external communication, and the MCU main chip circuit is electrically connected to a USB circuit for communication with a PC.

[0018] Compared with existing technologies, a flexible and reliable dual communication interface is constructed through RS-485 communication circuit and USB circuit: the RS-485 interface, with its strong anti-common-mode interference capability and long-distance transmission characteristics, ensures that the detection system can stably and reliably interact with remote equipment in complex electromagnetic vehicle environments; while the USB interface provides a convenient bridge for high-speed data upload, in-depth analysis and system firmware upgrade between the field and the PC.

[0019] Another technical solution of the present invention is to provide a method for testing the performance of an in-vehicle audio amplifier, comprising the following steps: The input and output audio signals of the audio amplifier under test are obtained through a signal input-output differential circuit, and the pre-processed analog audio signals are converted into digital signals through analog-to-digital conversion. The sound pressure signal collected by the external microphone is obtained through the microphone detection circuit; The voltage and current signals of the external temperature probe are obtained through the temperature detection circuit; The current signal of the external current clamp is obtained through a current acquisition and amplification circuit; The MCU main chip circuit receives and processes all the above signals, calculates the frequency response, distortion, sound pressure, temperature, voltage, and current parameters, and displays the calculated performance parameters through the external display circuit.

[0020] By synchronously acquiring and processing audio input and output signals, sound pressure signals, temperature signals, and current signals, the MCU main chip uniformly calculates and generates key performance parameters such as frequency response, distortion, sound pressure, temperature, voltage, and current. This enables a comprehensive evaluation of the amplifier's electrical performance, acoustic characteristics, and thermal state in a single test, significantly improving detection efficiency and spatiotemporal consistency of data. It completely overcomes the technical difficulties of traditional methods, which require separate measurements using different devices and make data correlation and comparison difficult.

[0021] In one possible implementation, the step of the MCU main chip circuit receiving and processing all the above signals includes selecting a test item through user operation function keys and switching the corresponding test circuit by the MCU control.

[0022] Compared with existing technologies, the user selects test items by operating function keys and the MCU controls the automatic switching of corresponding test circuits, which simplifies the operation process and significantly improves the testing efficiency.

[0023] In one possible implementation, the detected performance parameters are also transmitted to an external device via a communication interface circuit.

[0024] Compared with existing technologies, the real-time transmission of detection data to external devices via communication interfaces enables remote monitoring, massive storage, and in-depth analysis of detection data, greatly enhancing the data value of detection results and the scalability of the system. Attached Figure Description

[0025] Figure 1 This is a system block diagram of a vehicle-mounted audio amplifier performance testing system according to the present invention; Figure 2 This is a circuit diagram of the signal input / output differential circuit and the first analog-to-digital conversion circuit in a vehicle-mounted audio amplifier performance testing system of the present invention; Figure 3 The circuit diagram shows the second analog-to-digital converter circuit, microphone detection circuit, temperature detection circuit, current acquisition and amplification circuit, and power supply circuit in a vehicle-mounted audio amplifier performance testing system of the present invention. Figure 4 This is a circuit diagram of the MCU main chip circuit, external display circuit, communication interface circuit and USB interface circuit in a vehicle-mounted audio amplifier performance testing system of the present invention. Figure 5 This is a flowchart of the collaborative operation in a vehicle-mounted audio amplifier performance testing method of the present invention; Figure 6 This is a flowchart of voltage and current analysis in a vehicle-mounted audio amplifier performance testing method of the present invention; Figure 7 This is a flowchart of decibel analysis in a vehicle-mounted audio amplifier performance testing method of the present invention; Figure 8 This is a flowchart of the power resistance analysis in a vehicle-mounted audio amplifier performance testing method of the present invention; Figure 9 This is a flowchart of the Fourier transform analysis in the performance testing method of an in-vehicle audio amplifier according to the present invention; Figure 10 This is a flowchart of microphone analysis in a vehicle-mounted audio amplifier performance testing method of the present invention; Figure 11 This is a system setup flowchart for a vehicle-mounted audio amplifier performance testing method according to the present invention. Detailed Implementation

[0026] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0027] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0028] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0029] See Figures 1-4 As shown in the figure, this application discloses a vehicle audio amplifier performance testing system, including: The signal input-output differential circuit is used to receive the audio analog signals from the preamp input and the postamp output of the vehicle audio amplifier under test, respectively, and to perform noise reduction and sampling detection processing on the signals. The first analog-to-digital converter circuit is electrically connected to the signal input-output differential circuit and is used to convert the processed audio analog signal into an audio digital signal. The microphone detection circuit is used to receive and amplify the audio signals collected by the external microphone. The second analog-to-digital converter circuit is electrically connected to the microphone detection circuit and is used to convert the processed microphone audio signal into an audio digital signal. Temperature detection circuit, used to receive signals from NTC resistor or external temperature probe to obtain temperature analog signals; The current acquisition and amplification circuit is used to acquire the current signal from the external current clamp and amplify it. The MCU main chip circuit is electrically connected to the first analog-to-digital conversion circuit, the second analog-to-digital conversion circuit, the temperature detection circuit, and the current acquisition and amplification circuit, respectively, to receive various digital or analog signals and process them to obtain sound pressure, temperature, frequency response, distortion, voltage, and current parameters. The external display circuit is electrically connected to the MCU main chip circuit and is used to receive and display various parameters processed by the MCU main chip circuit.

[0030] By integrating multiple dedicated signal conditioning channels, including signal input / output differential circuits, microphone detection circuits, temperature detection circuits, and current acquisition and amplification circuits, and using a high-precision analog-to-digital converter, the system achieves synchronous, rapid, and accurate measurement of key amplifier performance parameters through a unified MCU main chip. This completely changes the traditional testing methods, which suffer from scattered equipment, cumbersome operation, and asynchronous data, greatly improving testing efficiency and the accuracy of results. It is especially suitable for rapid on-site diagnosis and comprehensive performance evaluation in vehicle environments.

[0031] See Figure 2 As shown, in this embodiment, the signal input / output differential circuit includes eight differential circuits, wherein the input terminals of four differential circuits are electrically connected to the four audio input channels of the audio amplifier under test, and the input terminals of the other four differential circuits are electrically connected to the four audio output channels of the audio amplifier under test.

[0032] By designing eight independent differential circuits, which are respectively connected to the four input channels and four output channels of the vehicle audio amplifier, the system achieves full-channel synchronous and parallel testing capability for multi-channel audio systems. This not only significantly improves testing efficiency and avoids the tedious operation of repeatedly switching channels in traditional methods, but also ensures that the input and output signals are compared on the same time reference. This provides a reliable guarantee for accurately analyzing key performance parameters such as amplifier gain, frequency response, distortion, and channel consistency, and is particularly suitable for the comprehensive testing needs of current mainstream multi-channel vehicle audio systems.

[0033] See Figure 3 As shown, the microphone detection circuit includes amplifier U11. The positive input terminal of amplifier U11 is electrically connected to the positive terminal of the microphone through capacitor C35, and the negative terminal of the microphone is grounded. The positive input terminal of amplifier U11 is grounded through resistor R57. The positive input terminal of amplifier U11 is electrically connected to the first terminal of capacitor C33 through resistor R51, and the second terminal of capacitor C33 is grounded. The positive terminal of the microphone is electrically connected to the first terminal of capacitor C33 through resistor R52. The first terminal of capacitor C33 is electrically connected to the power supply through resistor FB5. The negative input terminal of amplifier U11 is grounded through resistor R59. The negative input terminal of amplifier U11 is electrically connected to the output terminal of amplifier U11 through resistor R56. The output terminal of amplifier U11 is electrically connected to the second analog-to-digital converter circuit through series resistors R53 and R50. A voltage regulator circuit is connected in parallel across resistor R50. The voltage regulator circuit includes capacitor C32, resistor R48, resistor R49, and Zener diode D4. The connection terminals of resistors R53 and R50 are electrically connected to the negative terminal of Zener diode D4. The positive terminal of Zener diode D4 is connected in series with resistor R49, resistor R48, and capacitor C32 to the other end of resistor R50.

[0034] By employing a high-precision amplifier U11 to construct an amplification structure with bias and feedback, and combining it with a power supply filtering and signal conditioning network composed of capacitor C33 and resistors R51 / R52 / FB5, the anti-interference capability and signal-to-noise ratio of the microphone signal are effectively improved. In particular, an innovative parallel voltage regulator circuit composed of Zener diode D4 and resistors and capacitors is introduced at the output end, which can accurately limit the voltage amplitude sent to the subsequent ADC. This not only prevents signal overshoot from damaging sensitive devices, but also ensures the dynamic range and linearity of the sampled signal under different sound pressure environments, thus laying a reliable hardware foundation for realizing high-precision sound pressure measurement and FFT spectrum analysis.

[0035] See Figure 3 As shown, in this embodiment, the temperature detection circuit includes an NTC detection circuit for detecting the temperature of the internal power amplifier board and an external temperature probe detection circuit for detecting the temperature of the external power amplifier heatsink or speaker. The NTC detection circuit includes resistors NTC1 and NTC2. One end of resistor NTC1 is grounded, and the other end is electrically connected to the power supply through resistor R26. A capacitor C12 is connected in parallel across resistor NTC1, and the connection point between resistor NTC1 and resistor R26 is electrically connected to the MCU main chip circuit. One end of resistor NTC2 is grounded, and the other end is electrically connected to the power supply through resistor R27. A capacitor C13 is connected in parallel across resistor NTC2, and the connection point between resistor NTC1 and resistor R27 is electrically connected to the MCU main chip circuit. The external temperature probe detection circuit includes an external temperature probe, with the negative terminal of the external temperature probe grounded. The positive terminal of the external temperature probe is electrically connected to the main chip circuit through resistor R29. One end of resistor R29, which is electrically connected to the main chip circuit, is grounded through capacitor C14. A bidirectional trigger diode E1 is connected in parallel across the two ends of the external temperature probe. The positive terminal of the external temperature probe is electrically connected to the power supply through resistor R28.

[0036] The system employs a combined internal and external detection design. Internally, two independent NTC detection circuits (NTC1 and NTC2) perform multi-point synchronous temperature monitoring of key locations on the power amplifier board, ensuring the comprehensiveness and reliability of internal temperature data. Externally, a dedicated temperature probe detection circuit is used, and a bidirectional trigger diode E1 is innovatively introduced as the core overvoltage protection component. This effectively suppresses static electricity or surge impacts that may be introduced due to long-distance connections to external probes. Thus, while achieving accurate monitoring of the temperature of external heat sinks or speakers, the system greatly improves the durability and anti-interference capability of the entire detection system in complex automotive electrical environments.

[0037] See Figure 3 As shown, in this embodiment, the current acquisition and amplification circuit includes a high-current detection circuit for detecting large currents and a low-current detection circuit for detecting small currents. The input terminal of the high current detection circuit is electrically connected to the input terminal of the external current clamp, and the output terminal of the high current detection circuit is electrically connected to the MCU main chip circuit. The input terminal of the low current detection circuit is electrically connected to the output terminal of the high current detection circuit, and the output terminal of the low current detection circuit is electrically connected to the MCU main chip circuit.

[0038] By adopting a dual-channel collaborative detection architecture for large and small currents, seamless and accurate measurement of the wide dynamic range current of the vehicle audio amplifier is achieved. The small current detection channel cleverly obtains the signal from the output of the front-end large current channel and performs secondary amplification processing, enabling it to accurately capture the milliampere-level standby static current. This allows for high-precision acquisition of both large and small currents simultaneously without the need for range switching. This eliminates the data interruption problem caused by range switching in traditional detection and significantly improves the efficiency and accuracy of current measurement, perfectly adapting to the full-condition testing needs of vehicle audio systems from standby to full-load operation.

[0039] See Figure 4 As shown, in this embodiment, the external display circuit is an LCD screen used to display parameter information processed by the MCU main chip circuit. The LCD screen is electrically connected to the MCU main chip circuit.

[0040] By using an LCD display as an external display unit, the multi-dimensional parameters (such as sound pressure, temperature, frequency response, voltage and current) processed by the MCU main chip can be presented in a high-contrast and visual manner. It not only supports real-time display of various data formats such as waveforms, spectrum, and values, but also provides an intuitive human-machine interface for on-site technicians. This greatly facilitates the rapid reading and comprehensive analysis of various performance indicators of the vehicle-mounted audio amplifier, effectively improving the efficiency of testing and the accuracy of interpretation.

[0041] See Figure 4 As shown, in this embodiment, the MCU main chip circuit is electrically connected to an RS-485 communication circuit for providing data transmission and external communication, and the MCU main chip circuit is electrically connected to a USB circuit for communication with a PC.

[0042] By using RS-485 communication circuits and USB circuits, a flexible and reliable dual communication interface is constructed: the RS-485 interface, with its strong anti-common-mode interference capability and long-distance transmission characteristics, ensures that the detection system can stably and reliably exchange data with remote equipment in complex electromagnetic vehicle environments; while the USB interface provides a convenient bridge for high-speed data upload, in-depth analysis, and system firmware upgrades between the field and the PC. Example

[0043] See Figure 1-11 As shown, this embodiment provides a method for testing the performance of an in-vehicle audio amplifier, including the following steps: The input and output audio signals of the audio amplifier under test are obtained through a signal input-output differential circuit, and the pre-processed analog audio signals are converted into digital signals through analog-to-digital conversion. The sound pressure signal collected by the external microphone is obtained through the microphone detection circuit; The voltage and current signals of the external temperature probe are obtained through the temperature detection circuit; The current signal of the external current clamp is obtained through a current acquisition and amplification circuit; The MCU main chip circuit receives and processes all the above signals, calculates the frequency response, distortion, sound pressure, temperature, voltage, and current parameters, and displays the calculated performance parameters through the external display circuit.

[0044] By synchronously acquiring and processing audio input and output signals, sound pressure signals, temperature signals, and current signals, the MCU main chip uniformly calculates and generates key performance parameters such as frequency response, distortion, sound pressure, temperature, voltage, and current. This enables a comprehensive evaluation of the amplifier's electrical performance, acoustic characteristics, and thermal state in a single test, significantly improving detection efficiency and spatiotemporal consistency of data. It completely overcomes the technical difficulties of traditional methods, which require separate measurements using different devices and make data correlation and comparison difficult.

[0045] The step of receiving and processing all the above signals in the MCU main chip circuit includes selecting test items through user operation function keys and switching the corresponding test circuits by the MCU.

[0046] The user can select test items by using function keys and the MCU will automatically switch the corresponding test circuit, simplifying the operation process and significantly improving the testing efficiency.

[0047] In this embodiment, the detected performance parameters are also transmitted to an external device via a communication interface circuit.

[0048] The detection data is transmitted to external devices in real time through the communication interface, enabling remote monitoring, massive storage and in-depth analysis of the detection data, which greatly enhances the data value of the detection results and the scalability of the system.

[0049] See Figure 5 As shown, the method in this embodiment involves the collaborative operation of a handheld terminal and a field terminal, wherein: When the handheld device determines that remote sampling is required, it sends a sampling request to the field terminal. Upon receiving a sampling request, the field unit parses the request, switches the analog channel, and performs ADC sampling. If the sampling request is a curve sampling, the field end pre-renders the sampled data into curve data and packages it into curve data; if it is a single-point sampling, the ADC data is packaged directly. The on-site terminal sends the packaged sampling data as a remote sample to the handheld terminal; The handheld device receives remote samples and forwards them to the currently running application (App) for processing.

[0050] See Figure 6 As shown, the application (App) running on the handheld device includes a voltage and current (VA) analysis App, which performs the following steps: Initialize the working environment; During operation, in response to data events, the received sample data is processed to obtain voltage and current data; Request that the display interface be updated based on the voltage and current data; During operation, in response to timed events, a remote sampling request is sent to the field terminal when data is to be collected.

[0051] See Figure 7 As shown, the application (App) running on the handheld device includes a decibel (dB) analysis App, which performs the following steps: Initialize the working environment; During operation, in response to data events, the received sample data is processed to obtain the first voltage value V1 and the second voltage value V2, and the voltage gain Gv is calculated based on the first voltage value V1 and the second voltage value V2. Then, the decibel value is calculated according to the formula dB = 20lg(Gv). Request that the display interface be updated based on the decibel value; During operation, in response to timed events, a remote sampling request is sent to the field terminal when data is to be collected.

[0052] See Figure 8 As shown, the application (App) running on the handheld device includes a power resistance (WΩ) analysis App, which performs the following steps: Initialize the working environment; During operation, in response to data events, the received sample data is processed to obtain the voltage value V and the current value A, and the power value W and the resistance value Ω are calculated based on the voltage value and the current value. Request that the display interface be updated based on the power and resistance values; During operation, in response to timed events, a remote sampling request is sent to the field terminal when data is to be collected.

[0053] See Figure 9 As shown, the application (App) running on the handheld device includes a Fast Fourier Transform (FFT) analysis App, which performs the following steps: Initialize the working environment; During operation, in response to data events, the received remote sample data is decompressed, and waveform rendering and FFT analysis are performed simultaneously based on the decompressed data. Request an update to the display interface to present the waveforms and FFT analysis results; During operation, in response to timed events, a remote sampling request is sent to the field terminal when data is to be collected.

[0054] See Figure 10 As shown, the application (App) running on the handheld device includes a microphone (MIC) analysis App, which performs the following steps: Initialize the working environment; During operation, in response to data events, the sound pressure level is calculated based on the received sample data and a fast Fourier transform (FFT) spectrum analysis is performed. Request an update to the display interface to present the sound pressure level and FFT spectrum analysis results; During operation, in response to timed events, local ADC sampling is performed to obtain sample data when data is to be collected.

[0055] See Figure 11 As shown, the applications (Apps) running on the handheld device include the system settings App, which performs the following steps: Initialize the working environment and load the configuration parameters from the non-volatile memory (NVMEM); During operation, it responds to key events to switch between items to be set or to set item values; During operation, in response to a timed event, perform at least one of the following operations: When temperature data is available for acquisition, read the analog-to-digital converter (ADC) data and calculate the temperature; When an update to the display is required, request a redraw of the display interface; Before exiting, save the configuration parameters to non-volatile memory (NVMEM).

[0056] In the description of the embodiments of this application, it should be noted that the terms "inner" and "outer" and other terms indicating direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0057] In the description of this application, the references to terms such as "an embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0058] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An in-vehicle audio amplifier performance detection system, characterized by, The application relates to a vehicle audio amplifier testing device. The signal input and output differential circuit is used for respectively connecting audio analog signals from front-stage input and rear-stage output of a vehicle audio amplifier to be tested, and performing noise reduction and sampling detection processing on the signals. The first analog-digital conversion circuit is electrically connected with the signal input and output differential circuit, and is used for converting the processed audio analog signals into audio digital signals. The microphone detection circuit is used for receiving audio signals collected by an external microphone and performing amplification processing. The second analog-digital conversion circuit is electrically connected with the microphone detection circuit, and is used for converting the processed microphone audio signals into audio digital signals. The temperature detection circuit is used for connecting signals from an NTC resistor or an external temperature probe to obtain temperature analog signals. The current collection and amplification circuit is used for collecting current signals of an external current clamp and performing amplification processing. The MCU main chip circuit is electrically connected with the first analog-digital conversion circuit, the second analog-digital conversion circuit, the temperature detection circuit and the current collection and amplification circuit respectively, is used for receiving various digital signals or analog signals, and is used for processing to obtain sound pressure, temperature, frequency response, distortion, voltage and current parameters. The external display part circuit is electrically connected with the MCU main chip circuit, and is used for receiving and displaying various parameters processed by the MCU main chip circuit.

2. The in-vehicle audio amplifier performance detection system of claim 1, wherein, The signal input and output differential circuit includes eight differential circuits, four input ends of four differential circuits are electrically connected with four audio input channels of the audio amplifier to be tested, and input ends of the other four differential circuits are electrically connected with four audio output channels of the audio amplifier to be tested.

3. The in-vehicle audio amplifier performance detection system of claim 1, wherein, The microphone detection circuit includes an amplifier U11. The positive input end of the amplifier U11 is electrically connected with the positive electrode of a microphone through a capacitor C35, the negative electrode of the microphone is grounded, the positive input end of the amplifier U11 is grounded through a resistor R57, the positive input end of the amplifier U11 is electrically connected with the first end of a capacitor C33 through a resistor R51, the second end of the capacitor C33 is grounded, the positive electrode of the microphone is electrically connected with the first end of the capacitor C33 through a resistor R52, the first end of the capacitor C33 is electrically connected with a power supply through a resistor FB5, the negative input end of the amplifier U11 is grounded through a resistor R59, the negative input end of the amplifier U11 is electrically connected with the output end of the amplifier U11 through a resistor R56, the output end of the amplifier U11 is electrically connected with the second analog-digital conversion circuit through a resistor R53 and a resistor R50 in series, The resistor R50 is connected with a voltage stabilizing circuit in parallel at both ends, the voltage stabilizing circuit includes a capacitor C32, a resistor R48, a resistor R49 and a voltage stabilizing diode D4, the connection end of the resistor R53 and the resistor R50 is electrically connected with the negative electrode of the voltage stabilizing diode D4, the positive electrode of the voltage stabilizing diode D4 is connected with the resistor R49, the resistor R48 and the capacitor C32 in series, and the other end of the resistor R50 is electrically connected.

4. The in-vehicle audio amplifier performance detection system of claim 1, wherein, The temperature detection circuit includes an NTC detection circuit for detecting the temperature of an internal power amplifier board and an external temperature probe detection circuit for detecting the temperature of an external power amplifier heat sink or horn. The NTC detection circuit comprises an NTC1 resistor and an NTC2 resistor, one end of the NTC1 resistor is grounded, the other end of the NTC1 resistor is electrically connected with the power supply through a resistor R26, a capacitor C12 is connected in parallel across the NTC1 resistor, and the connection end of the NTC1 resistor and the resistor R26 is electrically connected with the MCU main chip circuit; one end of the NTC2 resistor is grounded, the other end of the NTC2 resistor is electrically connected with the power supply through a resistor R27, a capacitor C13 is connected in parallel across the NTC2 resistor, and the connection end of the NTC1 resistor and the resistor R27 is electrically connected with the MCU main chip circuit; The external temperature probe detection circuit comprises an external temperature probe, the negative electrode of the external temperature probe is grounded, the positive electrode of the external temperature probe is electrically connected with the main chip circuit through a resistor R29, one end of the resistor R29 electrically connected with the main chip circuit is grounded through a capacitor C14, a bidirectional trigger diode E1 is connected in parallel across the external temperature probe, and the positive electrode of the external temperature probe is electrically connected with the power supply through a resistor R28.

5. The in-vehicle audio amplifier performance detection system of claim 1, wherein, The current collection and amplification circuit comprises a large-current detection circuit for detecting a large current and a small-current detection circuit for detecting a small current; The input end of the large-current detection circuit is electrically connected with the external current clamp input end, the output end of the large-current detection circuit is electrically connected with the MCU main chip circuit, the input end of the small-current detection circuit is electrically connected with the output end of the large-current detection circuit, and the output end of the small-current detection circuit is electrically connected with the MCU main chip circuit.

6. The in-vehicle audio amplifier performance detection system of claim 1, wherein, The external display part circuit is an LCD display screen for displaying the parameter information processed by the MCU main chip circuit, and the LCD display screen is electrically connected with the MCU main chip circuit.

7. The in-vehicle audio amplifier performance detection system of claim 1, wherein, The MCU main chip circuit is electrically connected with a communication interface circuit for providing data transmission and external communication, the communication interface circuit is an RS-485 communication circuit, and the MCU main chip circuit is electrically connected with a USB circuit for communication connection with a PC end.

8. A method of detecting performance of an in-vehicle audio amplifier according to any one of claims 1 to 7, characterized by, The method comprises the following steps: The input and output audio signals of the audio amplifier to be tested are acquired through the signal input and output difference circuit, and the preprocessed audio analog signals are converted into digital signals through analog-to-digital conversion; The sound pressure signals collected by the external microphone are acquired through the microphone detection circuit; The voltage and current signals of the external temperature probe are acquired through the temperature detection circuit; The current signals of the external current clamp are acquired through the current collection and amplification circuit; The MCU main chip circuit receives and processes all the signals, calculates the frequency response, distortion, sound pressure, temperature, voltage and current parameters, and displays the performance parameters calculated through the external display part circuit.

9. The in-vehicle audio amplifier performance detection method of claim 8, wherein, In the step of receiving and processing all the signals by the MCU main chip circuit, the test items are selected through the user operation function keys, and the corresponding test circuits are switched by the MCU control.

10. The in-vehicle audio amplifier performance detection method of claim 8, wherein, The performance parameters detected are transmitted to the external equipment through the communication interface circuit.

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