Lossless remote control audio signal circuit

Abstract

The utility model provides a lossless remote control audio signal circuit, which comprises a potentiometer, a microprocessor and an electronic volume controller, one end of the potentiometer is connected with a power supply and is connected with an AD sampling pin of the microprocessor, and an enable signal output pin of the microprocessor is connected with a latch signal input pin of the electronic volume controller. A clock signal output pin of the microprocessor is connected with a clock signal input pin of the electronic volume controller, a data signal output pin of the microprocessor is connected with a data signal input pin of the electronic volume controller, and the electronic volume controller is provided with an audio signal input pin and an audio signal output pin. And the electronic volume controller performs three-wire serial data control on the input audio signal according to the data signal, the enable signal and the clock signal received from the microprocessor so as to change the volume of the audio signal, and outputs the audio signal to the power amplifier through the audio signal output pin. The circuit eliminates the problems of attenuation, noise and the like of audio signals caused by the length of a wire.

Description

Technical Field

[0001] This utility model belongs to the field of audio control technology, specifically relating to a lossless remote control audio signal circuit. Background Technology

[0002] Currently, when using a remote control to adjust the signal in a car power amplifier, a telephone jack is connected to a potentiometer via a wire. The resistance of the adjustable potentiometer changes the signal strength, thereby controlling the amplifier's output power. The connection method is as follows: Figure 1 As shown. In this connection method, the wire length is approximately 5m, and it is not a twisted-pair cable. Due to the antenna effect caused by the wire, interference is easily introduced. Furthermore, after the two ends are connected, the voltage division effect of the resistor causes signal attenuation. Specifically, in the speaker, when the remote control is connected, the sound volume is noticeably reduced, and a "buzzing" sound appears. This noise is perceptible to the human ear and severely affects the auditory experience. Summary of the Invention

[0003] In view of the problems existing in the background technology, the purpose of this utility model is to provide a lossless remote control audio signal circuit that can avoid signal attenuation caused by remote sound adjustment.

[0004] The objective of this utility model can be achieved through the following technical solution: A lossless remote control audio signal circuit, characterized in that it includes a potentiometer, a microprocessor, and an electronic volume controller. One end of the potentiometer is connected to a power supply and to the AD sampling pin of the microprocessor. The enable signal output pin of the microprocessor is connected to the latch signal input pin of the electronic volume controller. The clock signal output pin of the microprocessor is connected to the clock signal input pin of the electronic volume controller. The data signal output pin of the microprocessor is connected to the data signal input pin of the electronic volume controller. The electronic volume controller has an audio signal input pin and an audio signal output pin. The microprocessor samples the change in voltage of the potentiometer and converts it into a corresponding data signal, which is then output to the electronic volume controller through the data signal output pin. At the same time, the microprocessor outputs an enable signal and a clock signal to the electronic volume controller. The electronic volume controller performs three-wire serial data control on the input audio signal according to the received data signal, enable signal, and clock signal to change its volume, and outputs the volume to the power amplifier through the audio signal output pin.

[0005] Preferably, the audio signal input pin of the electronic volume controller is connected to a first capacitor, and the audio signal output pin of the electronic volume controller is connected to a second capacitor.

[0006] Preferably, the first capacitor is a non-polarized capacitor; the second capacitor is a polarized capacitor, with its positive terminal connected to the audio signal output pin of the electronic volume controller and its negative terminal connected to an external power amplifier.

[0007] Preferably, the microprocessor is further connected to a power amplifier protection circuit, which includes a first resistor, a second resistor, a transistor, a diode, and a third capacitor. The first end of the first resistor is connected to the protection signal output pin of the microprocessor, and the second end of the first resistor is connected to the first end of the second resistor and the base of the transistor. The second end of the second resistor is grounded. The emitter of the transistor is grounded, and the collector is connected to the cathode of the diode and the first end of the third capacitor. The anode of the diode outputs an SD signal to the power amplifier. The second end of the third capacitor is grounded.

[0008] Preferably, the microprocessor is an MC32F7361TM.

[0009] Preferably, the electronic volume controller is NJW1159.

[0010] Preferably, the potentiometer is a VR1000B linear potentiometer.

[0011] Preferably, a third resistor is connected in series between the potentiometer and the AD sampling pin of the microprocessor.

[0012] Compared with the prior art, the present invention has the following advantages: 1. After connecting the remote control, the output signal size remains unchanged, eliminating interference caused by excessively long wires from the source; and eliminating noise generated when the wires are long, thus improving the output sound quality of the power amplifier. Attached Figure Description

[0013] Figure 1 This refers to the audio signal circuit used in existing technologies.

[0014] Figure 2 This is a schematic diagram of the lossless remote control audio signal circuit structure of this utility model. Detailed Implementation

[0015] 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 intended to explain this utility model, and should not be construed as limiting this utility model.

[0016] like Figure 2As shown, the lossless remote control audio signal circuit provided by this utility model is characterized by including a potentiometer, a microprocessor, and an electronic volume controller. One end of the potentiometer is connected to a power supply and to the AD sampling pin of the microprocessor. The enable signal output pin of the microprocessor is connected to the latch signal input pin of the electronic volume controller. The clock signal output pin of the microprocessor is connected to the clock signal input pin of the electronic volume controller. The data signal output pin of the microprocessor is connected to the data signal input pin of the electronic volume controller. The electronic volume controller has an audio signal input pin and an audio signal output pin. The microprocessor samples the voltage change of the potentiometer and converts it into a corresponding data signal, which is then output to the electronic volume controller through the data signal output pin. At the same time, the microprocessor outputs an enable signal and a clock signal to the electronic volume controller. The electronic volume controller performs three-wire serial data control on the input audio signal according to the received data signal, enable signal, and clock signal to change its volume, and outputs the volume to the power amplifier through the audio signal output pin. The potentiometer is connected to a rotary remote control. When the remote control is rotated, the resistance of the potentiometer changes, causing a voltage change. The microprocessor's AD sampling pin detects the voltage change and converts it into a digital signal. This digital signal, along with the enable and clock signals, is sent to the electronic volume controller. Simultaneously, the preamplifier audio signal is input to the electronic volume controller. The electronic volume controller uses the data, enable, and clock signals to perform three-wire serial data control on the input audio signal, achieving digital adjustment of the input audio signal's volume. The signal is then output to an external power amplifier through the audio signal output pin.

[0017] Specifically, the electronic volume controller is model NJW1159. In this embodiment, its IN L is used as the audio signal input pin, which is connected to a first capacitor C81. The preamp audio signal is filtered by the first capacitor C81 before being input to the electronic volume controller. It should be noted that the first capacitor C81 is a non-polarized capacitor. The B outL pin of the electronic volume controller is used as the audio output pin. The audio signal after volume adjustment is output to the external amplifier through this pin; this pin is connected to a polarized capacitor.

[0018] The audio signal output pin of the electronic volume controller is connected to a polarized second capacitor C92. The positive terminal of the second capacitor C92 is connected to the B out L pin of the electronic volume controller, and the negative terminal is connected to the external power amplifier.

[0019] In this embodiment, the microprocessor is an MC32F7361TM microcontroller. The P0 pin of this microcontroller serves as the data signal output pin, connected to the data signal input pin DATA of the electronic volume controller via resistor R198; the P2 pin serves as the clock signal output pin, connected to the clock signal input pin CLOCK of the electronic volume controller via resistor R67; the P3 pin serves as the AD acquisition pin, connected to the potentiometer VR100 via a third resistor R246; the P4 pin serves as the enable signal output pin, connected to the latch signal input pin LATCH of the electronic volume controller via resistor R60A; and the P5 pin serves as the protection signal output pin, connected to the power amplifier protection circuit. Specifically, the power amplifier protection circuit includes a first resistor R244, a second resistor R245, a transistor Q16, a diode D2P, and a third capacitor C192. The first terminal of the first resistor R244 is connected to the protection signal output pin P5 of the microprocessor. The second terminal of the first resistor R244 is connected to the first terminal of the second resistor R245 and the base of the transistor Q16. The second terminal of the second resistor R245 is grounded. The emitter of the transistor Q16 is grounded, and its collector is connected to the cathode of the diode D2P and the first terminal of the third capacitor C192. The anode of the diode D2P outputs an SD signal to the power amplifier. The second terminal of the third capacitor C192 is grounded. It should be noted that the potentiometer used in this embodiment is a VR1000B linear potentiometer.

[0020] This invention uses a microprocessor to convert the voltage changes of a potentiometer into digital quantities. Then, an electronic volume controller performs three-wire serial data control based on the received data signal, clock signal, and enable signal. This achieves the control of audio signal magnitude by changes in DC voltage, avoids the influence of wire length on the output audio signal, and ensures that the output signal has no attenuation and no noise, thus significantly improving the sound quality of the power amplifier output.

[0021] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A lossless remote control audio signal circuit, characterized in that, The system includes a potentiometer, a microprocessor, and an electronic volume controller. One end of the potentiometer is connected to a power supply and to the AD sampling pin of the microprocessor. The enable signal output pin of the microprocessor is connected to the latch signal input pin of the electronic volume controller. The clock signal output pin of the microprocessor is connected to the clock signal input pin of the electronic volume controller. The data signal output pin of the microprocessor is connected to the data signal input pin of the electronic volume controller. The electronic volume controller has an audio signal input pin and an audio signal output pin. The microprocessor samples the voltage change of the potentiometer, converts it into a corresponding data signal, and outputs it to the electronic volume controller through the data signal output pin. At the same time, the microprocessor outputs an enable signal and a clock signal to the electronic volume controller. The electronic volume controller performs three-wire serial data control on the input audio signal according to the received data signal, enable signal, and clock signal to change its volume and outputs it to the power amplifier through the audio signal output pin.

2. The lossless remote control audio signal circuit according to claim 1, characterized in that, The audio signal input pin of the electronic volume controller is connected to a first capacitor, and the audio signal output pin of the electronic volume controller is connected to a second capacitor.

3. The lossless remote control audio signal circuit according to claim 2, characterized in that, The first capacitor is a non-polarized capacitor; the second capacitor is a polarized capacitor, with its positive terminal connected to the audio signal output pin of the electronic volume controller and its negative terminal connected to an external power amplifier.

4. A lossless remote control audio signal circuit according to claim 1, 2, or 3, characterized in that, The microprocessor is also connected to a power amplifier protection circuit, which includes a first resistor, a second resistor, a transistor, a diode, and a third capacitor. The first end of the first resistor is connected to the protection signal output pin of the microprocessor, and the second end of the first resistor is connected to the first end of the second resistor and the base of the transistor. The second end of the second resistor is grounded. The emitter of the transistor is grounded, and the collector is connected to the cathode of the diode and the first end of the third capacitor. The anode of the diode outputs an SD signal to the power amplifier. The second end of the third capacitor is grounded.

5. A lossless remote control audio signal circuit according to claim 1, 2, or 3, characterized in that, The microprocessor is MC32F7361TM.

6. A lossless remote control audio signal circuit according to claim 1, 2, or 3, characterized in that, The electronic volume controller is NJW1159.

7. A lossless remote control audio signal circuit according to claim 1, 2, or 3, characterized in that, The potentiometer is a VR1000B linear potentiometer.

8. A lossless remote control audio signal circuit according to claim 1, 2, or 3, characterized in that, A third resistor is connected in series between the potentiometer and the AD sampling pin of the microprocessor.

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