Volume attenuation control circuit
By using a combination of a multi-tap transformer fine-tuning unit and a coarse adjustment unit in the volume attenuation control circuit, the problem of low accuracy and high cost of volume attenuation adjustment in the prior art is solved, and a high-precision and low-cost volume attenuation effect is achieved.
Patent Information
- Application Number
- CN202421245590.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-03
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-06-03
AI Technical Summary
In the prior art, the adjustment accuracy of volume attenuation is not high, and the high-precision volume attenuation circuit requires a large number of components, resulting in excessive cost.
The volume attenuation adjustment is performed by combining coarse and fine adjustment, and high-precision and fast large-range attenuation are achieved through the multi-tap transformer fine adjustment unit and the coarse adjustment unit.
High-precision volume attenuation is achieved, while reducing the use of components and avoiding excessive cost.
Smart Images
Figure CN222600099U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of audio, in particular to a volume attenuation control circuit. Background Art
[0002] When users use speakers to play audio files, such as playing music or listening to books, they often need to adjust the output volume of the speakers, which means that users need to flexibly adjust the volume attenuation of the speakers at any time.
[0003] In the prior art, the volume attenuation is usually adjusted by rotating a stepping potentiometer to gradually adjust the volume attenuation. That is, the volume attenuation can only be adjusted sequentially and step by step. Moreover, the existing volume attenuation adjustment accuracy is not high. Because the higher the attenuation accuracy, the more components are used in the volume attenuation circuit, and the higher the cost. Moreover, in the prior art, a high-precision volume attenuation circuit requires a large-range knob switch or a switch with too many gears, which causes the cost of the audio product to be too high. Utility Model Content
[0004] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a volume attenuation control circuit, which adjusts the volume attenuation by combining coarse adjustment and fine adjustment, improves the volume attenuation accuracy, and avoids the use of a large number of components, thereby effectively reducing the cost of the volume attenuation circuit.
[0005] The purpose of this utility model is achieved through the following technical solutions:
[0006] A volume attenuation control circuit comprises: an attenuation control module, a relay control module and a potentiometer module;
[0007] The attenuation control module receives the attenuation control signal, and outputs a corresponding relay control signal to the relay control module according to the attenuation control signal; the relay control module controls the potentiometer module according to the relay control signal;
[0008] The relay control module includes a fine-tuning relay control unit and a coarse-tuning relay control unit;
[0009] The potentiometer module includes a fine-tuning potentiometer unit and a coarse-tuning potentiometer unit; the fine-tuning control end of the fine-tuning potentiometer unit is connected to the fine-tuning relay control unit; the coarse-tuning control end of the coarse-tuning potentiometer unit is connected to the coarse-tuning relay control unit; the input end of the fine-tuning potentiometer unit is externally connected to an audio signal, the output end of the fine-tuning potentiometer unit is connected to the input end of the coarse-tuning potentiometer unit, and the output end of the coarse-tuning potentiometer unit outputs an attenuated audio signal.
[0010] Preferably, the potentiometer module is a multi-tap transformer potentiometer; the fine-tuning potentiometer unit is a multi-tap transformer fine-tuning unit, and the coarse-tuning potentiometer unit is a multi-tap transformer coarse-tuning unit.
[0011] Preferably, the potentiometer module is a resistive stepping potentiometer; the fine-tuning potentiometer unit is a resistive stepping fine-tuning unit, and the coarse-tuning potentiometer unit is a resistive stepping coarse-tuning unit.
[0012] Preferably, the attenuation control module includes a single chip microcomputer.
[0013] Preferably, the volume attenuation control circuit further comprises a current amplifying driving module, the input end of the current amplifying driving module is connected to the output end of the attenuation control module, and the output end of the current amplifying driving module is connected to the relay control module.
[0014] Preferably, the current amplification and driving module is ULN2003.
[0015] Preferably, the number of the current amplification and driving modules is two, and the two current amplification and driving modules are respectively connected to the fine-tuning relay control unit and the coarse-tuning relay control unit in a one-to-one correspondence.
[0016] Preferably, the fine-tuning relay control unit includes a plurality of first coil control units, and the plurality of first coil control units are respectively connected to a plurality of output terminals of the current amplification driving module in a one-to-one correspondence.
[0017] Preferably, the coarse adjustment relay control unit includes a plurality of second coil control units, and the plurality of second coil control units are respectively connected to a plurality of output terminals of the current amplification drive module in a one-to-one correspondence.
[0018] Preferably, the volume attenuation control circuit further comprises a power supply module, an input end of the power supply module is externally connected to a power supply; and an output end of the power supply module is connected to a power input end of the attenuation control module.
[0019] Compared with the prior art, the utility model has at least the following advantages:
[0020] The fine-tuning attenuation of the multi-tap transformer fine-tuning unit realizes high-precision attenuation, and the coarse-tuning attenuation of the multi-tap transformer coarse-tuning unit realizes fast large-range attenuation; the combination of fine-tuning attenuation and coarse-tuning attenuation simultaneously realizes large-range fast attenuation and high-precision attenuation, and does not require the addition of a large number of components (such as relay control coils, switch units, etc.), achieving low cost.
[0021] The volume attenuation control circuit of the utility model overcomes the conflicting problem between large-range attenuation and high-precision attenuation, and has low implementation cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1 It is a schematic diagram of the volume attenuation control circuit of the utility model;
[0024] Figure 2 for Figure 1 Partial circuit schematic diagram of the volume attenuation control circuit shown;
[0025] Figure 3 The circuit diagram of the potentiometer module of Example 1;
[0026] Figure 4 2 is a circuit schematic diagram of the potentiometer module of Example 2. DETAILED DESCRIPTION
[0027] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the accompanying drawings. The accompanying drawings show preferred embodiments of the present invention. Example 1
[0028] like Figure 1 and Figure 2 As shown, a volume attenuation control circuit 10 includes: an attenuation control module 100, a relay control module 200, a potentiometer module 300 and a power module 400. The input end of the power module 400 is externally connected to a power supply; the output end of the power module 400 is connected to the power input end of the attenuation control module 400. In this embodiment, the input end of the power module 400 is externally connected to a 12V power supply, and the output end of the power module 400 inputs a 5V power supply voltage to the power input end of the attenuation control module 400. The power module 400 provides a stable 5V voltage to the attenuation control module 100 to ensure that the attenuation control module 100 works stably, thereby ensuring the stability of the volume attenuation control circuit 10. As a preferred embodiment, the power module 400 includes a voltage stabilizer, and the model of the voltage stabilizer is LM78M05. Of course, the voltage stabilizer is not limited to the LM78M05 model voltage stabilizer, and other models of voltage stabilizers can also be used.
[0029] like Figure 1 and Figure 2As shown, the attenuation control module 100 receives the attenuation control signal and outputs a corresponding relay control signal to the relay control module 200 according to the attenuation control signal; the relay control module 200 controls the potentiometer module 300 according to the relay control signal. The attenuation control module 100 receives the attenuation control signal through an external interface, wherein the external interface may be an interface such as Uart, IIC, SPI, etc., but is not limited to these interfaces. Specifically, the attenuation control module 100 includes a single-chip microcomputer. The model of the single-chip microcomputer is not limited.
[0030] like Figure 1 As shown, specifically, the relay control module 200 includes a fine-tuning relay control unit 210 and a coarse-tuning relay control unit 220. The potentiometer module 300 includes a fine-tuning potentiometer unit 310 and a coarse-tuning potentiometer unit 320; the fine-tuning control end of the fine-tuning potentiometer unit 310 is connected to the fine-tuning relay control unit 210; the coarse-tuning control end of the coarse-tuning potentiometer unit 320 is connected to the coarse-tuning relay control unit 220; the input end of the fine-tuning potentiometer unit 310 is externally connected to the audio signal, the output end of the fine-tuning potentiometer unit 310 is connected to the input end of the coarse-tuning potentiometer unit 320, and the output end of the coarse-tuning potentiometer unit 320 outputs the attenuated audio signal.
[0031] like Figure 1 As shown, in this embodiment, the volume attenuation control circuit 10 further includes a current amplification driving module, the input end of the current amplification driving module is connected to the output end of the attenuation control module 100, and the output end of the current amplification driving module is connected to the relay control module 200. As a preferred embodiment, the current amplification driving module is ULN2003. In this embodiment, the number of the current amplification driving modules is two, and the two current amplification driving modules are respectively connected to the fine-tuning relay control unit 210 and the coarse-tuning relay control unit 220 in a one-to-one correspondence. In order to facilitate the description and distinction, the two current amplification driving modules are now named as the first current amplification driving module 510 and the second current amplification driving module 520. The input end of the first current amplification driving module 510 is connected to the output end of the attenuation control module 100, and the output end is connected to the input end of the fine-tuning relay control unit 210; the input end of the second current amplification driving module 520 is connected to the output end of the attenuation control module 100, and the output end is connected to the coarse-tuning relay control unit 220.
[0032] like Figure 1 and Figure 2As shown, in this embodiment, the fine-tuning relay control unit 210 includes a plurality of first coil control units, which are respectively connected to a plurality of output terminals of the first current amplification driving module 510 in a one-to-one correspondence. The coarse-tuning relay control unit 220 includes a plurality of second coil control units, which are respectively connected to a plurality of output terminals of the second current amplification driving module 520 in a one-to-one correspondence.
[0033] like Figure 1 and Figure 2 As shown, in this embodiment, the number of first coil control units is 6, which are relay control coils K1B~K6B respectively. The number of second coil control units is 6, which are relay control coils K7B~K12B respectively. The coarse adjustment relay control unit 220 also includes a mute coil control unit, and the mute coil control unit is a mute control coil KMute. The input ends of the relay control coils K1B~K6B are respectively connected to the output ends of the first current amplification drive module IC4 in a one-to-one correspondence. The input ends of the relay control coils K7B~K12B are respectively connected to the output ends of the second current amplification drive module IC3 in a one-to-one correspondence. The mute control coil KMute is connected to the mute output end of the first current amplification drive module IC3.
[0034] like Figure 3 As shown, in this embodiment, the potentiometer module 300 is a multi-tap transformer potentiometer. The fine-tuning potentiometer unit 310 is a multi-tap transformer fine-tuning unit; the coarse-tuning potentiometer unit 320 is a multi-tap transformer coarse-tuning unit. The input end of the multi-tap transformer fine-tuning unit serves as an audio signal input end A to receive an audio signal; the output end B of the multi-tap transformer fine-tuning unit serves as an input end of the multi-tap transformer coarse-tuning unit, and the output end of the multi-tap transformer coarse-tuning unit serves as an audio signal output end C to output an attenuated audio signal.
[0035] like Figure 2 and Figure 3 As shown, the multi-tap transformer fine-tuning unit has 6 taps, that is, 6 switch relays K1A to K6A. The relay control coils K1B to K6B respectively control the on and off of the switch relays K1A to K6A in a one-to-one correspondence.
[0036] like Figure 2 and Figure 3As shown, the multi-tap transformer coarse adjustment unit has 7 taps, of which 6 taps are 6 switch relays K7A~K12A. The relay control coils K7B~K12B correspond to the on and off of the switch relays K7A~K12A respectively. The other tap is connected to the mute switch relay KMute_A. It can be understood that: the relay control coils K1B~K6B correspond to the control switch relays K1A~K6A; the relay control coils K7B~K12B correspond to the control switch relays K7A~K12A; the mute control coil KMute corresponds to the control of the mute switch relay KMute_A.
[0037] Please also read Figure 1 , Figure 2 and Figure 3 When the volume attenuation control circuit 10 is working, the external 12V power supply is stabilized by the voltage stabilizer LM78M05 and then outputs a 5V power supply voltage. The 5V power supply voltage is further stabilized and filtered by the voltage stabilizing and filtering unit (composed of the voltage stabilizing capacitor C4 and the filtering capacitor C2 in parallel) and then inputs a stable 5V power supply voltage to the single-chip microcomputer IC1;
[0038] The external interface inputs the attenuation control signal (serial port signal) from the single-chip microcomputer IC1; the single-chip microcomputer IC1 outputs the corresponding relay control signal according to the attenuation control signal (that is, the pins P1.0~P1.6 and pins P2.0~P2.6 of the single-chip microcomputer IC1 generate control level signals of different combinations) to the first current amplification drive module IC4 and the second current amplification drive module IC3 for amplification, and then controls the relay control coils K1B~K6B and the relay control coils K7B~K12B respectively, thereby controlling the on and off of the switch relays K1A~K6A, the switch relays K7A~K12A, and the mute switch relay KMute_A;
[0039] The multi-tap transformer fine-tuning unit is used for fine-tuning attenuation, and the attenuation range is from 0Db to -7.5Db, and the step attenuation is -1.5Db; the multi-tap transformer coarse-tuning unit is used for coarse-tuning attenuation, and the attenuation range is from 0Db to -45Db, and the step attenuation is -9Db; the attenuation of the volume attenuation control circuit 10 can be arbitrarily combined by the attenuation of the multi-tap transformer fine-tuning unit and the attenuation of the multi-tap transformer coarse-tuning unit;
[0040] The audio signal is input from the audio signal input terminal A, and is output from the audio signal output terminal C after being attenuated by the multi-tap transformer potentiometer; specifically, after the audio signal is input from the audio signal input terminal A, it is output from the output terminal B after being fine-tuned and attenuated by the multi-tap transformer fine-tuning unit; the audio signal after fine-tuning and attenuation is input from the output terminal B to the multi-tap transformer coarse-tuning unit, and is output from the audio signal output terminal C after being coarse-tuned and attenuated by the multi-tap transformer coarse-tuning unit; the audio signal output from the audio signal output terminal C has been fine-tuned and coarse-tuned; the attenuation amount of the audio signal after being attenuated by the multi-tap transformer potentiometer is a combination of the fine-tuning attenuation amount of the multi-tap transformer fine-tuning unit and the coarse-tuning attenuation amount of the multi-tap transformer coarse-tuning unit;
[0041] For example, when attenuation of -10.5Db is required, switch relay K2A and switch relay K11A need to be closed; when attenuation of -19.5Db is required, switch relay K2A and switch relay K10A need to be closed; that is, the total attenuation of the audio signal is the sum of the attenuation of the multi-tap transformer fine-tuning unit and the attenuation of the multi-tap transformer coarse-tuning unit;
[0042] The fine-tuning attenuation of the multi-tap transformer fine-tuning unit realizes high-precision attenuation, and the coarse-tuning attenuation of the multi-tap transformer coarse-tuning unit realizes fast large-range attenuation; the combination of fine-tuning attenuation and coarse-tuning attenuation realizes large-range fast attenuation and high-precision attenuation at the same time, and does not require the addition of a large number of components (such as relay control coils, switch units, etc.), and the implementation cost is low. The volume attenuation control circuit 10 of the utility model overcomes the contradiction between large-range attenuation and high-precision attenuation, and the implementation cost is low. Example 2
[0043] like Figure 4 As shown, in this embodiment, the potentiometer module 300 is a resistive stepping potentiometer; the fine-tuning potentiometer unit 310 is a resistive stepping fine-tuning unit, and the coarse-tuning potentiometer unit 320 is a resistive stepping coarse-tuning unit.
[0044] like Figure 4 As shown, the input end of the resistive step fine-tuning unit serves as the audio signal input end A1 to receive the audio signal; the output end B1 of the resistive step fine-tuning unit serves as the input end of the resistive step coarse-tuning unit, and the output end of the resistive step coarse-tuning unit serves as the audio signal output end C1 to output the attenuated audio signal.
[0045] like Figure 2 and Figure 4 As shown, the resistive step fine-tuning unit has 6 taps, that is, 6 switch relays K1A1 to K6A1. The relay control coils K1B to K6B respectively control the on and off of the switch relays K1A1 to K6A1 in a one-to-one correspondence.
[0046] like Figure 2 and Figure 4 As shown, the resistive stepping coarse adjustment unit has 7 taps, of which 6 taps are 6 switch relays K7A1~K12A1. The relay control coils K7B~K12B correspond to the on and off of the switch relays K7A1~K12A1. The other tap is connected to the mute switch relay KMute_A1. It can be understood that: the relay control coils K1B~K6B correspond to the control switch relays K1A1~K6A1; the relay control coils K7B~K12B correspond to the control switch relays K7A1~K12A1; the mute control coil KMute corresponds to the control of the mute switch relay KMute_A1.
[0047] The audio signal is input from the audio signal input terminal A1, and is output from the audio signal output terminal C1 after being attenuated by the resistive stepping potentiometer; specifically, after the audio signal is input from the audio signal input terminal A1, it is output from the output terminal B1 after being fine-tuned and attenuated by the resistive stepping fine-tuning unit; the audio signal after fine-tuning and attenuation is input from the output terminal B1 to the resistive stepping coarse-tuning unit, and is output from the audio signal output terminal C1 after being coarse-tuned and attenuated by the resistive stepping coarse-tuning unit; the audio signal output from the audio signal output terminal C1 has been fine-tuned and coarse-tuned; the attenuation amount of the audio signal attenuated by the resistive stepping potentiometer is a combination of the fine-tuning attenuation amount of the resistive stepping fine-tuning unit and the coarse-tuning attenuation amount of the resistive stepping coarse-tuning unit;
[0048] The working principle of the resistive stepper potentiometer is the same as that of the multi-tap transformer potentiometer, so it will not be described here.
[0049] The other structures and principles of Example 2 are the same as those of Example 1 and will not be described in detail here.
[0050] The volume attenuation control circuit 10 of the utility model does not need to convert analog-to-digital or digital-to-analog signals, and can keep the signal undistorted; the signal-to-noise ratio is better than the prior art method using a digital potentiometer;
[0051] The volume attenuation control circuit 10 of the utility model can have more attenuation levels and higher attenuation accuracy than the prior art using a rotary switch stepping potentiometer;
[0052] The carbon film potentiometer used in the prior art is prone to wear and failure, generating noise; the volume attenuation control circuit 10 of the utility model does not require a carbon film potentiometer, has a long service life; and by using a sealed relay, the circuit is not easily damaged;
[0053] The volume attenuation control circuit 10 of the utility model can independently control each channel, can provide left and right channel balance adjustment, and can easily integrate remote control function;
[0054] The volume attenuation control circuit 10 of the utility model has an attenuation accuracy that is only affected by the accuracy of the multi-tap transformer potentiometer or the resistance value accuracy of the resistive stepping potentiometer, and the attenuation is more accurate.
[0055] The volume attenuation control circuit 10 of the utility model has high precision and can be applied to a balanced power amplifier to maintain the symmetry of the positive and negative half waves.
[0056] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.
Claims
1. A volume attenuation control circuit, characterized in that: include: Attenuation control module, relay control module and potentiometer module; The attenuation control module receives the attenuation control signal, and outputs a corresponding relay control signal to the relay control module according to the attenuation control signal; the relay control module controls the potentiometer module according to the relay control signal; The relay control module includes a fine-tuning relay control unit and a coarse-tuning relay control unit; The potentiometer module includes a fine-tuning potentiometer unit and a coarse-tuning potentiometer unit; the fine-tuning control end of the fine-tuning potentiometer unit is connected to the fine-tuning relay control unit; the coarse-tuning control end of the coarse-tuning potentiometer unit is connected to the coarse-tuning relay control unit; the input end of the fine-tuning potentiometer unit is externally connected to an audio signal, the output end of the fine-tuning potentiometer unit is connected to the input end of the coarse-tuning potentiometer unit, and the output end of the coarse-tuning potentiometer unit outputs an attenuated audio signal.
2. The volume attenuation control circuit according to claim 1, characterized in that: The potentiometer module is a multi-tap transformer type potentiometer; the fine-tuning potentiometer unit is a multi-tap transformer type fine-tuning unit, and the coarse-tuning potentiometer unit is a multi-tap transformer type coarse-tuning unit.
3. The volume attenuation control circuit according to claim 1, characterized in that: The potentiometer module is a resistive stepping potentiometer; the fine-tuning potentiometer unit is a resistive stepping fine-tuning unit, and the coarse-tuning potentiometer unit is a resistive stepping coarse-tuning unit.
4. The volume attenuation control circuit according to claim 1, characterized in that: The attenuation control module includes a single chip microcomputer.
5. The volume attenuation control circuit according to claim 1, characterized in that: It also includes a current amplification driving module, the input end of the current amplification driving module is connected to the output end of the attenuation control module, and the output end of the current amplification driving module is connected to the relay control module.
6. The volume attenuation control circuit according to claim 5, characterized in that: The number of the current amplification driving modules is two, and the two current amplification driving modules are respectively connected to the fine-tuning relay control unit and the coarse-tuning relay control unit in a one-to-one correspondence.
7. The volume attenuation control circuit according to claim 5, characterized in that: The fine-tuning relay control unit includes a plurality of first coil control units, and the plurality of first coil control units are respectively connected to a plurality of output terminals of the current amplification driving module in a one-to-one correspondence.
8. The volume attenuation control circuit according to claim 6, characterized in that: The coarse adjustment relay control unit includes a plurality of second coil control units, and the plurality of second coil control units are respectively connected to a plurality of output terminals of the current amplification drive module in a one-to-one correspondence.
9. The volume attenuation control circuit according to claim 1, characterized in that: It also includes a power supply module, the input end of which is externally connected to a power supply; and the output end of which is connected to the power input end of the attenuation control module.