Loudspeaker driving circuit and test equipment

Abstract

The utility model discloses a loudspeaker drive circuit and test equipment, including input module, gain switching module and signal amplification module, gain switching module includes multiplexing switch unit, rotatory coding switch unit and dynamic gain amplification unit, multiplexing switch unit's first input terminal is connected with rotatory coding switch unit, multiplexing switch unit's second input terminal is connected with rotatory coding switch unit, and dynamic gain amplification unit's second input terminal is connected with rotatory coding switch unit. The second input end of the multiplexing switch unit is connected with a gain resistance network and is connected to the input module through the gain resistance network, the output end of the multiplexing switch unit is connected with the dynamic gain amplification unit, and the input end of the signal amplification module is connected with the output end of the dynamic gain amplification unit. According to the utility model, multi-gear gain control can be provided, and the test requirements of loudspeakers with different powers can be met, so that the test precision is improved.

Description

Technical Field

[0001] This utility model relates to the field of audio testing technology, and in particular to a speaker driving circuit and testing equipment. Background Technology

[0002] In loudspeaker testing equipment, especially for low-power loudspeakers, the performance of the driver circuit directly affects the test accuracy and reliability. Most existing loudspeaker driver circuits adopt a fixed-gain single-stage amplification structure. Although they have basic driving capabilities, in practical applications, the single-gain mode cannot adapt to the testing requirements of loudspeakers with different power levels, resulting in a limited test dynamic range. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a loudspeaker driving circuit and testing equipment, capable of providing multi-level gain control to meet the testing needs of loudspeakers of different power levels, thereby improving testing accuracy.

[0004] On one hand, this utility model embodiment provides a speaker driving circuit, including:

[0005] Input module;

[0006] The gain switching module includes a multiplexer unit, a rotary encoder unit, and a dynamic gain amplifier unit. The first input terminal of the multiplexer unit is connected to the rotary encoder unit. The second input terminal of the multiplexer unit is connected to a gain resistor network and is connected to the input module through the gain resistor network. The output terminal of the multiplexer unit is connected to the dynamic gain amplifier unit.

[0007] The signal amplification module has its input terminal connected to the output terminal of the dynamic gain amplification unit.

[0008] According to some embodiments of the present invention, the input module includes an input interface unit and a differential amplifier unit. The input interface unit is connected to the input terminal of the differential amplifier unit, and the output terminal of the differential amplifier unit is connected to the gain switching module.

[0009] According to some embodiments of this utility model, the input terminal of the differential amplifier unit is connected to a coupling capacitor.

[0010] According to some embodiments of this utility model, the differential amplifier unit adopts an integrated circuit of model INA134UA.

[0011] According to some embodiments of the present invention, the second input terminal of the multiplexer unit has multiple gain selection pins, the gain resistor network includes multiple resistor units connected in series, a gain node is provided between adjacent resistor units, and the gain node is connected to the gain selection pin of the multiplexer unit.

[0012] According to some embodiments of this utility model, the number of gain selection pins is 8. The first gain selection pin is connected to the input module, the second gain selection pin is connected to the reference voltage terminal, and the remaining gain selection pins are connected to the corresponding gain nodes of the gain resistor network.

[0013] According to some embodiments of this utility model, the dynamic gain amplification unit adopts an integrated circuit of model OPA1611.

[0014] According to some embodiments of the present invention, the signal amplification module includes a first amplification unit and a second amplification unit, wherein the input terminals of the first amplification unit and the second amplification unit are both connected to the output terminal of the dynamic gain amplification unit.

[0015] According to some embodiments of the present invention, the first amplification unit adopts an integrated circuit of model LM3886.

[0016] On the other hand, this utility model embodiment provides a testing device, including the above-described speaker driving circuit.

[0017] The embodiments of this utility model have at least the following beneficial effects:

[0018] The input module inputs the signal to the gain switching module. The gain switching module realizes gain control and signal amplification through a multiplexed switching unit, a rotary encoder switching unit, and a dynamic gain amplification unit. The signal is then output through the signal amplification module, which can provide multiple levels of gain control to meet the testing requirements of speakers with different power levels, thereby improving the testing accuracy.

[0019] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0021] Figure 1 This is a schematic block diagram of the speaker driving circuit according to an embodiment of the present invention;

[0022] Figure 2 for Figure 1 The circuit schematic of the input module of the speaker driver circuit is shown.

[0023] Figure 3 for Figure 1 The circuit diagram of the multiplexing switch unit and the rotary encoder switch unit of the speaker driver circuit is shown.

[0024] Figure 4 for Figure 1 The circuit diagram shown is of the gain resistor network of the speaker driver circuit.

[0025] Figure 5 for Figure 1 The circuit diagram shown is of the dynamic gain amplification unit of the speaker driver circuit.

[0026] Figure 6 for Figure 1 The circuit diagram shown is of the signal amplification module of the speaker driver circuit.

[0027] Figure label:

[0028] Input module 100, input interface unit 110, differential amplifier unit 120, gain switching module 200, multiplexer switch unit 210, rotary encoder switch unit 220, dynamic gain amplifier unit 230, gain resistor network 240, resistor unit 241, signal amplifier module 300. Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0030] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first," "second," etc., are used in the description, they are only for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the sequential relationship of the indicated technical features.

[0031] In the description of this utility model, unless otherwise explicitly defined, the terms "setting", "installation", "connection", etc. should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in combination with the specific content of the technical solution.

[0032] This embodiment discloses a test device including a speaker driver circuit. Please refer to... Figure 1 The speaker driver circuit includes an input module 100, a gain switching module 200, and a signal amplification module 300. The gain switching module 200 includes a multiplexer unit 210, a rotary encoder switch unit 220, and a dynamic gain amplifier unit 230. The first input terminal of the multiplexer unit 210 is connected to the rotary encoder switch unit 220, and the second input terminal of the multiplexer unit 210 is connected to a gain resistor network 240 and connected to the input module 100 through the gain resistor network 240. The output terminal of the multiplexer unit 210 is connected to the dynamic gain amplifier unit 230, and the input terminal of the signal amplification module 300 is connected to the output terminal of the dynamic gain amplifier unit 230.

[0033] The input module 100 inputs the signal to the gain switching module 200. The gain switching module 200 achieves gain control and signal amplification through a multiplexer unit 210, a rotary encoder switch unit 220, and a dynamic gain amplifier unit 230. The rotary encoder switch unit 220 converts the mechanical rotation of the knob into digital pulses or analog voltage / current signals, which are then input to the multiplexer unit 210. The multiplexer unit 210 switches the path according to the input signal from the rotary encoder switch unit 220, thereby changing the gain of the dynamic gain amplifier unit 230 in conjunction with the gain resistor network 240, achieving primary signal amplification and output, which is then output through the signal amplification module 300. This provides multi-level gain control to meet the testing requirements of speakers with different power levels, thereby improving testing accuracy.

[0034] Please refer to Figure 2 The input module 100 includes an input interface unit 110 and a differential amplifier unit 120. The input interface unit 110 is connected to the input terminal of the differential amplifier unit 120, and the output terminal of the differential amplifier unit 120 is connected to the gain switching module 200. The differential amplifier unit 120 can achieve balanced signal reception, eliminate common-mode interference, and achieve impedance matching of the input stage to adapt to the output characteristics of different audio source devices, and amplify the signal through a fixed gain for output. A coupling capacitor is connected to the input terminal of the differential amplifier unit 120, such as... Figure 2 As shown by C601 and C602, the input interface unit 110 and the differential amplifier unit 120 can be coupled together to improve anti-interference capability. The differential amplifier unit 120 uses an INA134UA integrated circuit, as shown by U603 in the figure. It employs a fully differential structure to achieve a common-mode rejection ratio (CMRR) >100dB, effectively suppressing electromagnetic interference introduced by long-distance transmission. Furthermore, its ultra-low noise density provides a foundation for a high signal-to-noise ratio in subsequent amplification.

[0035] Please refer to Figure 3 and Figure 4 The second input terminal of the multiplexer unit 210 has multiple gain selection pins, such as... Figure 3 As shown by markings S1-S8 in chip U604, the gain resistor network 240 includes multiple series-connected resistor units 241. Each resistor unit 241 includes one or more resistors. Gain nodes, such as nodes S21-S27, are provided between adjacent resistor units 241. The gain nodes are connected to the gain selection pins of the multiplexer switch unit 210. For example, the number of gain selection pins is 8 (e.g., ...). Figure 3 As shown by markings S1-S8 in chip U604, the first gain selection pin (as shown by marking S8) is connected to the input module 100, the second gain selection pin (as shown by marking S1) is connected to the reference voltage terminal, and the remaining gain selection pins (as shown by markings S2-S7) are connected to the corresponding gain nodes (as shown by markings S22-S27) of the gain resistor network 240. Please refer to... Figure 5 The dynamic gain amplifier unit 230 uses an OPA1611 integrated circuit, as indicated by the label U605. It allows for variable gain setting via the gain resistor network 240 and provides low voltage noise through a built-in BJT (brick-and-tube) input stage. The OPA1611 integrated circuit employs a current feedback architecture to achieve high conversion efficiency, ensuring phase consistency of the audio signal. It also features built-in overload protection circuitry to prevent clipping distortion, meeting THD+N requirements, and uses a high-frequency roll-off network to suppress radio frequency interference, improving circuit stability.

[0036] Please refer to Figure 6 The signal amplification module 300 includes a first amplification unit and a second amplification unit. Figure 6 (Only the circuit schematic of the first amplification unit is shown). The input terminals of both the first and second amplification units are connected to the output terminal of the dynamic gain amplification unit 230. Dual-channel amplification can be achieved through the first and second amplification units to meet testing requirements. The first and second amplification units have the same structure. The first amplification unit uses an LM3886 integrated circuit, which has a differential input stage, a current drive stage, and an output stage. The differential input stage receives the signal from the previous stage and converts it into a differential form, improving dynamic range and anti-interference capability. The current drive stage converts the voltage signal into a high-current signal. The output stage uses a bipolar transistor push-pull structure to achieve signal output. Furthermore, the LM3886 integrated circuit integrates over-temperature protection, over-current protection, and DC offset protection, which helps improve the stability of circuit operation.

[0037] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A loudspeaker drive circuit, characterised by include: Input module (100); The gain switching module (200) includes a multiplexer unit (210), a rotary encoder unit (220), and a dynamic gain amplifier unit (230). The first input terminal of the multiplexer unit (210) is connected to the rotary encoder unit (220), and the second input terminal of the multiplexer unit (210) is connected to a gain resistor network (240) and connected to the input module (100) through the gain resistor network (240). The output terminal of the multiplexer unit (210) is connected to the dynamic gain amplifier unit (230). The input terminal of the signal amplification module (300) is connected to the output terminal of the dynamic gain amplification unit (230).

2. The loudspeaker drive circuit of claim 1, wherein, The input module (100) includes an input interface unit (110) and a differential amplifier unit (120). The input interface unit (110) is connected to the input terminal of the differential amplifier unit (120), and the output terminal of the differential amplifier unit (120) is connected to the gain switching module (200).

3. The loudspeaker drive circuit of claim 2, wherein, The input terminal of the differential amplifier unit (120) is connected to a coupling capacitor.

4. A loudspeaker drive circuit according to claim 2 or 3, characterised in that, The differential amplifier unit (120) uses an integrated circuit of model INA134UA.

5. The loudspeaker drive circuit of claim 1, wherein, The second input terminal of the multiplexer unit (210) has multiple gain selection pins. The gain resistor network (240) includes multiple resistor units (241) connected in series. Gain nodes are provided between adjacent resistor units (241). The gain nodes are connected to the gain selection pins of the multiplexer unit (210).

6. The loudspeaker drive circuit of claim 5, wherein, The number of gain selection pins is 8. The first gain selection pin is connected to the input module (100), the second gain selection pin is connected to the reference voltage terminal, and the remaining gain selection pins are connected to the corresponding gain nodes of the gain resistor network (240).

7. A loudspeaker drive circuit according to claim 5 or 6, characterised in that, The dynamic gain amplification unit (230) uses an integrated circuit of model OPA1611.

8. The loudspeaker driving circuit according to claim 1, characterized in that, The signal amplification module (300) includes a first amplification unit and a second amplification unit, and the input terminals of the first amplification unit and the second amplification unit are both connected to the output terminal of the dynamic gain amplification unit (230).

9. The loudspeaker drive circuit of claim 8, wherein, The first amplification unit uses an integrated circuit of model LM3886.

10. A test apparatus, characterized by, Includes the speaker driving circuit as described in any one of claims 1 to 9.

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