Circuit for preventing impact sound

Abstract

The utility model provides an impact sound prevention circuit. The circuit comprises a power supply module, a power-on impact sound prevention module, a power-down impact sound prevention module and an audio output module. The power-on anti-impact sound module is used for performing delay processing on the audio output module when the power supply module is turned on; the power-down impact sound prevention module is used for performing power-off processing on the audio output module when the power supply module is turned off; the on-off condition of the power supply module is judged through the power-on anti-impact sound module and the power-off anti-impact sound module, so that the working state of the audio output module is controlled, and an impact sound event can be responded in time during power-on and power-off.

Description

Technical Field

[0001] The utility model relates to the technical field of audio equipment, in particular to a circuit for preventing impact sound. Background Art

[0002] In audio electronic devices, especially power amplifiers and home audio systems, impact noise that often occurs when power is turned on or off has always been a serious problem. This noise is caused by the rapid charging or discharging of internal energy storage components (such as capacitors) when the power is turned on or off instantly, resulting in sudden changes in current and voltage, which causes physical vibrations in the speakers and emits obvious "banging" or "clicking" sounds. This impact sound not only greatly affects the user's listening experience, but also may cause irreversible physical damage to audio output devices such as speakers if it exists for a long time.

[0003] At present, most devices use software-controlled relay switches to prevent the generation of impact sounds. However, when the power is off, the software control often cannot handle the impact sound in time, resulting in the output of the impact sound.

[0004] In summary, the problems existing in the prior art need to be solved urgently. Utility Model Content

[0005] The utility model provides a circuit for preventing impact sound, which is used to solve the defects in the prior art and can respond to impact sound events during power-on and power-off in real time.

[0006] The utility model provides a circuit for preventing impact sound, comprising:

[0007] Power module, power-on anti-shock sound module, power-off anti-shock sound module and audio output module;

[0008] The power-on anti-impact sound module is used to perform delay processing on the audio output module when the power module is turned on;

[0009] The power-off anti-impact sound module is used to power off the audio output module when the power module is turned off;

[0010] The first output end of the power module is connected to the input end of the power-on anti-impact sound module, the second output end of the power module is connected to the input end of the power-off anti-impact sound module, the output end of the power-on anti-impact sound module is connected to the first input end of the audio output module, and the output end of the power-off anti-impact sound module is connected to the second input end of the audio output module.

[0011] According to a circuit for preventing impact sound provided by the utility model, the power-off impact sound prevention module includes a first capacitor, a first diode, a first transistor, and a second transistor, the emitter of the second transistor is grounded through the first capacitor, the anode of the first diode is connected to the emitter of the second transistor, the cathode of the first diode is connected to the base of the second transistor, the base of the second transistor is also connected to the power module, the collector of the second transistor is connected to the base of the first transistor, the collector of the first transistor is connected to the audio output module, and the emitter of the first transistor is grounded.

[0012] According to a circuit for preventing impact sound provided by the utility model, the power-on impact sound prevention module includes a second capacitor, a resistance unit, and a third transistor, the power supply module is connected to the input end of the resistance unit, the resistance unit is connected to the base and collector of the transistor, the emitter of the transistor is grounded, and the output end of the resistance unit is connected to the audio output module.

[0013] According to a circuit for preventing impact sound provided by the utility model, the audio output module includes a fourth transistor and a relay, the base of the fourth transistor is connected to the power-on impact sound prevention module, the base of the fourth transistor is also connected to the power-off impact sound prevention module, the emitter of the fourth transistor is grounded, the collector of the fourth transistor is connected to the relay, and the relay is connected to the audio input.

[0014] According to a circuit for preventing impact sound provided by the utility model, the first transistor is an NPN transistor, and the second transistor is a PNP transistor.

[0015] According to a circuit for preventing impact sound provided by the utility model, the first diode is a voltage-stabilizing diode.

[0016] According to a circuit for preventing impact sound provided by the utility model, the first transistor is an NPN transistor.

[0017] According to a circuit for preventing impact sound provided by the utility model, pin No. 8 of the relay is grounded.

[0018] According to a circuit for preventing impact sound provided by the utility model, the audio output module further includes a second diode, the anode of the diode is connected to the collector of the fourth transistor, and the cathode of the diode is connected to the relay.

[0019] According to a circuit for preventing impact sound provided by the utility model, the output voltage of the power module is 12V.

[0020] The utility model provides an impact sound prevention circuit, which comprises a power supply module, a power-on impact sound prevention module, a power-off impact sound prevention module and an audio output module; the power-on impact sound prevention module is used for delaying the audio output module when the power supply module is turned on; the power-off impact sound prevention module is used for powering off the audio output module when the power supply module is turned off; the switch status of the power supply module is judged by the power-on impact sound prevention module and the power-off impact sound prevention module, so as to control the working status of the audio output module, and can respond to the impact sound event in time when the power is on and the power is off. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 It is a structural schematic diagram of a circuit for preventing impact sound provided by the utility model;

[0023] Figure 2 This is a circuit diagram of the power-on anti-impact sound module provided by the utility model;

[0024] Figure 3 This is a circuit diagram of the power-off anti-impact sound module provided by the utility model;

[0025] Figure 4 It is a circuit diagram of the audio output module provided by the utility model; DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] In order to solve the problems in the prior art, the utility model proposes a circuit for preventing impact sound, so as to achieve timely response to impact sound events when powering on and off. The circuit for preventing impact sound is described below. Figure 1 As shown, it includes but is not limited to the following modules: a power supply module 110, a power-on anti-impact sound module 120, a power-off anti-impact sound module 130 and an audio output module 140;

[0028] The power-on anti-impact sound module 120 is used to perform delay processing on the audio output module 140 when the power module 110 is turned on;

[0029] The power-off anti-impact sound module 130 is used to power off the audio output module 140 when the power module 110 is turned off;

[0030] The first output end of the power module 110 is connected to the input end of the power-on anti-impact sound module 120, the second output end of the power module 110 is connected to the input end of the power-off anti-impact sound module 130, the output end of the power-on anti-impact sound module 120 is connected to the first input end of the audio output module 140, and the output end of the power-off anti-impact sound module 130 is connected to the second input end of the audio output module 140.

[0031] refer to Figure 2 As a further optional embodiment, the power-off anti-impact sound module includes a first capacitor, a first diode, a first transistor, and a second transistor, the emitter of the second transistor is grounded through the first capacitor, the anode of the first diode is connected to the emitter of the second transistor, the cathode of the first diode is connected to the base of the second transistor, the base of the second transistor is also connected to the power module, the collector of the second transistor is connected to the base of the first transistor, the collector of the first transistor is connected to the audio output module, and the emitter of the first transistor is grounded.

[0032] Specifically, the power-off anti-impact sound module includes a capacitor C1, a diode D2, a transistor Q1, and a transistor Q2. The emitter of the transistor Q2 is grounded through the capacitor C1, the positive electrode of the transistor Q2 is connected to the emitter of the transistor Q2, the negative electrode of the diode D2 is connected to the base of the transistor Q2, the base of the transistor Q2 is also connected to the power module, the collector of the transistor Q2 is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the audio output module, and the emitter of the transistor Q1 is grounded.

[0033] refer to Figure 3 As a further optional embodiment, the power-on anti-impact sound module includes a second capacitor, a resistance unit, and a third transistor. The power supply module is connected to the input end of the resistance unit, the resistance unit is connected to the base and collector of the transistor, the emitter of the transistor is grounded, and the output end of the resistance unit is connected to the audio output module.

[0034] Specifically, the power-on anti-impact sound module includes a capacitor C2, a resistor R1, a resistor R6, a resistor R9, a resistor R3 and a transistor Q3, a power module is connected to the collector of the transistor Q3 through the resistor R1 and the resistor R9, an emitter of the transistor Q3 is grounded, and a power module is connected to the base of the transistor Q3 through the resistor R6 and the capacitor C2. One end of the resistor R3 is connected to the resistor R1 and the resistor R9.

[0035] refer to Figure 4 As a further optional embodiment, the audio output module includes a fourth transistor and a relay, the base of the fourth transistor is connected to the power-on anti-impact sound module, the base of the fourth transistor is also connected to the power-off anti-impact sound module, the emitter of the fourth transistor is grounded, the collector of the fourth transistor is connected to the relay, and the relay is connected to the audio input.

[0036] Specifically, the audio output module includes a transistor Q4 and a relay JK1. The power-on anti-impact sound module and the power-off anti-impact sound module are connected to the base of the transistor Q4 through R17. The emitter of the transistor Q4 is grounded, and the collector is connected to pin 8 of the relay JK1, and is connected to pin 1 of the relay through a diode D3. Pin 3 of the relay is connected to the audio input (Audio input), and pin 4hao of the relay is used as the audio output (Audio output).

[0037] As a further optional embodiment, the first transistor is an NPN transistor, and the second transistor is a PNP transistor.

[0038] As a further optional embodiment, the first diode is a voltage regulator diode.

[0039] As a further optional embodiment, the first transistor is an NPN transistor.

[0040] As a further optional embodiment, pin 8 of the relay is grounded.

[0041] According to a circuit for preventing impact sound provided by the utility model, the audio output module further includes a second diode, the anode of the diode is connected to the collector of the fourth transistor, and the cathode of the diode is connected to the relay.

[0042] According to a circuit for preventing impact sound provided by the utility model, the output voltage of the power module is 12V.

[0043] refer to Figure 2 , Figure 3 and Figure 4 Based on the above embodiments, the working principle of the utility model is now described in detail:

[0044] When the device is powered on, the power-on anti-shock sound circuit and the power-off anti-shock sound circuit in the circuit work respectively.

[0045] During the power-on stage, in the power-on anti-impact sound circuit, the 12V voltage charges the capacitor C2 (22U / 50V) through the resistor R6 (47K ohms). At this time, the transistor Q3 is turned on, so that the voltage 12V flows into the reference ground through the resistors R1 (47K ohms) and R9 (1K ohms), generating a voltage division of about 0.25V. The 0.25V voltage through the resistors R3 (470 ohms) and R17 (10K ohms) reaches the base of the transistor Q4, but because the voltage is too low, Q4 cannot be turned on, resulting in the 8th pin of the relay JK1 not being grounded, the relay cannot work normally, and the impact sound is discharged through the reference ground.

[0046] At the same time, in the power-off stage, in the power-off anti-shock sound circuit, the 12V voltage charges the capacitor C1 (100U / 25V) through the voltage stabilizing diode D2 and the resistor R2 (1K ohm). At the same time, the 12V voltage reaches the base of the transistor Q2 through the resistor R8 (1K ohm), causing Q2 to work in the cut-off state. Since the 3rd pin of Q2 is connected to the resistor R14 and then grounded, the voltage of the 3rd pin of Q2 is low potential. This low potential reaches the base of the NPN transistor Q1 through the resistor R13 (10K ohm), causing Q1 to be in the cut-off state. At this time, the MUTE pin signal is only determined by the MUTE pin signal of the power-on shock sound circuit.

[0047] When the device is powered on and in normal working state, that is, after a certain period of time, the capacitor C2 in the power-on impact sound circuit is fully charged, so that Q3 is cut off, and 12V cannot reach the ground through resistors R1 (47K ohm) and R9 (1K ohm), resulting in R1 (47K ohm) and R9 (1K ohm) being unable to form a resistor voltage divider. The voltage 12V passes through resistors R3 (470 ohm) and R17 (10K ohm) to reach the base of Q4, making Q4 conduct, relay JK1 working, and audio can be output normally.

[0048] After the device is powered on for a period of time, the capacitor C1 (100U / 25V) in the power-off impact sound circuit is fully charged and the circuit enters the ready state.

[0049] When the device loses power, the 12V voltage of the power-on anti-shock circuit disappears. At this time, capacitor C2 (22U / 50V) begins to discharge toward resistor R6 (47K). Since the base collector pin 1 voltage of transistor Q3 remains low, Q3 is in the cut-off state. The discharge path of capacitor C2 (22U / 50V) is the entire system, the discharge duration can be ignored, and the impact on the MUTE signal can also be ignored.

[0050] At the same time, the 12V voltage of the power-off anti-shock sound circuit also disappears. After the voltage of capacitor C1 (100U / 25V) passes through resistor R2 (1K ohm), the reverse voltage of Zener diode D2 is cut off, so the discharge path of capacitor C1 (100U / 25V) can only be discharged through the path of transistor Q2 and resistor R4 (100K ohm). When the device is powered off, the voltage through resistor R8 is immediately converted to a low potential. Since transistor Q2 is a PNP transistor, Q2 is in the on state at this time, and the voltage of capacitor C1 reaches the base set of NPN transistor Q1 after passing through transistor Q2 and resistor R13 (10K ohm). At this time, Q1 is in the on state, and the MUTE signal is grounded through pins 3 and 2 of Q1, so that the MUTE pin level is pulled down. The voltage through the audio output control circuit resistor R17 (10K ohm) is low potential, the base set of Q4 is low potential, and Q4 is in the off state. Relay JK1 does not work and loses its switch adsorption ability. Pin 3 is disconnected from pin 4 and pin 3 is connected to pin 2. At this time, the impact sound audio will be output to the reference ground.

[0051] The utility model has the following advantages over the prior art:

[0052] Real-time: The hardware circuit has a short response time and can generate and process audio signals in real time, especially for fast transient sounds such as impact sounds. There is no need for software encoding and decoding and processing delays, and the performance is more immediate and accurate.

[0053] Stability: After the hardware circuit design is completed and debugged successfully, the performance is relatively stable and is not affected by the running status of the computer operating system or other software. Abnormal audio output will not occur due to system resource usage or program errors.

[0054] Power consumption and efficiency: Pure hardware solutions are usually more efficient in terms of power consumption, especially for embedded systems and mobile devices, because they avoid the CPU from performing complex calculations.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A circuit for preventing impact sound, characterized in that: include: Power module, power-on anti-shock sound module, power-off anti-shock sound module and audio output module; The power-on anti-impact sound module is used to perform delay processing on the audio output module when the power module is turned on; The power-off anti-impact sound module is used to power off the audio output module when the power module is turned off; The first output end of the power module is connected to the input end of the power-on anti-impact sound module, the second output end of the power module is connected to the input end of the power-off anti-impact sound module, the output end of the power-on anti-impact sound module is connected to the first input end of the audio output module, and the output end of the power-off anti-impact sound module is connected to the second input end of the audio output module.

2. The circuit for preventing impact sound according to claim 1, characterized in that: The power-off anti-impact sound module includes a first capacitor, a first diode, a first transistor, and a second transistor. The emitter of the second transistor is grounded through the first capacitor, the anode of the first diode is connected to the emitter of the second transistor, the cathode of the first diode is connected to the base of the second transistor, the base of the second transistor is also connected to the power module, the collector of the second transistor is connected to the base of the first transistor, the collector of the first transistor is connected to the audio output module, and the emitter of the first transistor is grounded.

3. The circuit for preventing impact sound according to claim 1, characterized in that: The power-on anti-impact sound module includes a second capacitor, a resistance unit, and a third transistor. The power supply module is connected to the input end of the resistance unit, the resistance unit is connected to the base and collector of the transistor, the emitter of the transistor is grounded, and the output end of the resistance unit is connected to the audio output module.

4. The circuit for preventing impact sound according to claim 1, characterized in that: The audio output module includes a fourth transistor and a relay. The base of the fourth transistor is connected to the power-on anti-impact sound module, and the base of the fourth transistor is also connected to the power-off anti-impact sound module. The emitter of the fourth transistor is grounded, and the collector of the fourth transistor is connected to the relay, and the relay is connected to the audio input.

5. The circuit for preventing impact sound according to claim 2, characterized in that: The first transistor is an NPN transistor, and the second transistor is a PNP transistor.

6. The circuit for preventing impact sound according to claim 2, characterized in that: The first diode is a voltage regulator diode.

7. The circuit for preventing impact sound according to claim 2, characterized in that: The first transistor is an NPN transistor.

8. The circuit for preventing impact sound according to claim 4, characterized in that: Pin 8 of the relay is grounded.

9. The circuit for preventing impact sound according to claim 4, characterized in that: The audio output module further includes a second diode, the anode of the diode is connected to the collector of the fourth transistor, and the cathode of the diode is connected to the relay.

10. The circuit for preventing impact sound according to claim 1, characterized in that: The output voltage of the power module is 12V.

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