CN219406290U

CN219406290U - Driving circuit of automobile alarm sounding unit

Info

Publication number: CN219406290U
Application number: CN202320474096.XU
Authority: CN
Inventors: 么传棚; 潘德凯; 赵韩; 李良源; 刘晓翔
Original assignee: Qingdao Jianbang Automobile Technology Co ltd
Current assignee: Qingdao Jianbang Automobile Technology Co ltd
Priority date: 2023-03-13
Filing date: 2023-03-13
Publication date: 2023-07-25
Anticipated expiration: 2033-03-13

Abstract

The utility model provides a driving circuit of an alarm sounding unit of an automobile, which comprises a sounding driving circuit, a sounding unit and a sounding rechecking circuit, wherein the sounding driving circuit is used for driving the sounding unit to generate sound; the sounding driving circuit comprises a class-D amplifier and an output filter; the class D amplifier is connected with the driving component and used for acquiring frequency and tone and amplifying the frequency and tone; the output filter is arranged at the output end of the class-D amplifier; the sound generating unit is a loudspeaker, and the loudspeaker is connected with the output end of the class D amplifier; the sounding rechecking circuit comprises an audio signal amplifier and a sampling resistor; the sampling resistor is arranged between the class D amplifier and the sounding unit; the input of the audio signal amplifier is respectively connected with two ends of the sampling resistor, and the output pin is connected with the driving component. The alarm sounding unit driving circuit provided by the utility model has a reliability review scheme, increases the convenience of circuit application and debugging, has the functions of speaker fault identification and alarm sounding abnormality detection, and greatly improves the use safety of a system and a user.

Description

Driving circuit of automobile alarm sounding unit

Technical Field

The utility model relates to the technical field of automobile alarm equipment, in particular to a driving circuit of an automobile alarm sounding unit.

Background

At present, a plurality of alarm sounding unit driving schemes are provided for a plurality of alarm prompt scenes such as reversing alarm prompt, tail gate extrusion locked-rotor prompt, safety belt wearing prompt and the like. In the driving scheme in the prior art, a driving unit such as an MCU (micro control Unit) is used for generating a driving alarm prompt tone, and the driving alarm prompt tone is amplified by a triode circuit and played by a sound generating element such as a loudspeaker.

However, the driving scheme of the alarm sounding unit in the prior art cannot meet the requirement of sounding with multiple tone qualities in multiple scenes. The triode circuit is adopted to amplify sound, so that serious device heating can be generated, and the efficiency of the driving circuit is reduced; meanwhile, the existing alarm sounding unit driving scheme has the defect that a plurality of alarm sounds exist, such as hoarseness or clunk sounds; different circuits are required to adjust the sound to meet the multiple sound requirements of different scenes, so that the corresponding hardware cost is increased; most importantly, the system cannot perform fault identification, and when the circuit has open circuit or short circuit and other conditions, the system has the risks of abnormal functions or burning out the driving circuit, and has great potential safety hazards.

Disclosure of Invention

The utility model provides a driving scheme of an alarm generation unit, which can effectively solve the defect of alarm sound, increase the convenience of circuit application and debugging, and simultaneously has the functions of speaker fault identification and alarm sound abnormality detection, thereby realizing the safety guarantee of the whole operation process of the alarm generation unit and greatly improving the use safety of a system and a user.

Specifically, the utility model provides an automobile alarm sounding unit driving circuit which is connected with a driving component and comprises a sounding driving circuit, a sounding unit and a sounding rechecking circuit;

the sounding driving circuit comprises a class-D amplifier U1 and an output filter;

the class D amplifier U1 is connected with the driving component and used for acquiring frequency and tone and amplifying the frequency and tone; the output filter comprises a first magnetic bead L1, a fourth capacitor C4, a second magnetic bead L2 and a sixth capacitor C6, wherein the first magnetic bead L1 and the fourth capacitor C4 are arranged at the positive electrode of the output end of the class D amplifier U1, and the second magnetic bead L2 and the sixth capacitor C6 are arranged at the negative electrode of the output end of the class D amplifier U1;

the sound generating unit is a loudspeaker, and the anode and the cathode of the loudspeaker are respectively connected with the anode and the cathode of the output end of the class D amplifier U1;

the sounding rechecking circuit comprises an audio signal amplifier U2 and a sampling resistor R4;

the sampling resistor R4 is arranged between the output end of the class D amplifier U1 and the sounding unit;

the audio signal amplifier U2 comprises an anode input pin, a cathode input pin and an output pin;

the positive electrode input pin and the negative electrode input pin are respectively connected with two ends of the sampling resistor R4, and the output pin is connected with the driving component.

Further, the sound production driving circuit comprises a high-pass filter circuit; the driving component is connected with the class D amplifier U1 through the high-pass filter circuit;

the high-pass filter circuit comprises a third capacitor C3 and a second resistor R2 which are connected in series.

Further, the sounding review circuit comprises a low-pass filter circuit, and the low-pass filter circuit is arranged between the audio signal amplifier U2 and the driving component;

the low-pass filter circuit comprises a sixth resistor R6 and an eighth capacitor C8; the sixth resistor R6 is connected in series between the audio signal amplifier U2 and the driving component, one end of the eighth capacitor C8 is connected with the driving component, and the other end of the eighth capacitor C8 is grounded.

Further, the class D amplifier U1 is further provided with an EPAD pin, and the EPAD pin is directly grounded and used for increasing the contact area between the chip and the ground and reducing the thermal resistance of the chip.

The beneficial effects achieved by the utility model are as follows:

the alarm sounding unit driving circuit provided by the utility model has a reliability review scheme, so that the convenience of circuit application and debugging is improved, the functions of speaker fault identification and alarm sounding abnormality detection are also realized, the safety guarantee of the whole operation process of the alarm sounding unit is realized, and the use safety of a system and a user is greatly improved.

The alarm sounding unit driving circuit provided by the utility model solves the defects of hoarseness, clunk and the like of an alarm, and solves the problem that a loudspeaker is broken and an MCU cannot recognize; the problem that a loudspeaker is short-circuited to burn out a power device is solved; the problem that MCU can not recognize when the output sound of the loudspeaker is inconsistent with the expected sound due to line reasons or damage of the loudspeaker is solved.

Drawings

Fig. 1 is a schematic circuit diagram of a driving circuit of an alarm sounding unit of an automobile according to an embodiment of the present utility model.

Detailed Description

The technical scheme of the present utility model will be described in more detail with reference to the accompanying drawings, and the present utility model includes, but is not limited to, the following examples.

As shown in fig. 1, the present utility model provides a driving circuit of an alarm sounding unit of an automobile, where the driving circuit of the alarm sounding unit of the automobile is connected with a driving unit, and the driving unit includes, but is not limited to, driving components such as an MCU, etc. for generating alarm sounds with different frequencies and tones.

The driving circuit of the automobile alarm sounding unit comprises a sounding driving circuit, a sounding unit and a sounding rechecking circuit.

The sounding driving circuit comprises a class-D amplifier, a high-pass filter circuit and an output filter.

The class D amplifier is provided with a mode control pin CTRL, an internal common mode reference voltage pin BYPASS, a non-inverting analog input terminal pin INP, an inverting analog input terminal pin INN, an output terminal negative terminal pin VON, an output terminal positive terminal pin VOP, a power supply positive terminal pin VDD, a power supply negative terminal pin GND, and an EPAD pin.

The operation mode control pin CTRL is connected to the c_spk_ctrl signal, which turns on the class D amplifier when high and turns off the class D amplifier when low.

The internal common mode reference voltage pin BYPASS is connected with a first capacitor C1 and a second capacitor C2 which are connected in parallel, and the other ends of the first capacitor C1 and the second capacitor C2 are grounded.

The pin INP of the non-inverting analog input terminal is connected to the driving unit through a high-pass filter circuit.

The inverting analog input pin INN is grounded through a third resistor R3 and a fifth capacitor C5 in series.

The negative electrode pin VON of the output end and the positive electrode pin VOP of the output end are respectively connected with the positive electrode and the negative electrode of the sounding unit through a plurality of corresponding output filters.

The output filter corresponding to the output end positive electrode pin VOP comprises a first magnetic bead L1 and a fourth capacitor C4; the output filter corresponding to the negative electrode pin VON of the output end comprises a second magnetic bead L2 and a sixth capacitor C6.

The power supply positive pole pin VDD is connected with the input voltage VCC, and the power supply negative pole pin GND is grounded.

The EPAD pin is grounded, and the EPAD pin is used for increasing the contact area of the chip and the ground, reducing the thermal resistance of the chip, facilitating the heat dissipation of the chip and reducing the temperature rise of the chip.

The sound generating unit is a loudspeaker.

The sounding rechecking circuit comprises an audio signal amplifier U2, a sampling resistor R4 and a low-pass filter circuit;

the sampling resistor R4 is arranged between the negative electrode pin VON of the output end and the negative electrode of the sounding unit, and two ends of the sampling resistor R4 are simultaneously connected with the signal amplifier.

The audio signal amplifier U2 has a ground pin, a positive input pin, a negative input pin, a gain setting pin, a power supply pin, a bypass pin, and an output pin.

The power supply pin is connected with a power supply, and the grounding pin is connected with the grounding end of the system; the bypass pin is grounded through a ninth capacitor C9 for decoupling through the capacitor.

The positive electrode input pin and the negative electrode input pin are respectively connected with two ends of the sampling resistor R4 and are used for acquiring audio signals.

The gain pin is connected to the gain setting pin through a ninth resistor R9 and a tenth capacitor C10 for adjusting the gain of the amplifier through the capacitive element.

The output pins are connected with the driving components through the low-pass filter circuit, so that the driving components can acquire the working state of the driving circuit.

The low-pass filter circuit comprises a sixth resistor R6 and an eighth capacitor C8 and is used for carrying out low-pass filtering on the signal output by the signal amplifier.

Specifically, in one embodiment, class D audio amplifier U1 employs an audio power amplifier model NS 4110B. The driving component audio output pin c_spk_out is input to the INP pin of NS4110B after high pass filtering by the 103 capacitor and the 220K resistor. The CTRL pin is connected to the C_SPK_CTRL signal while the 5v power supply is connected to the CTRL pin through a 10K resistor and in parallel with the C_SPK_CTRL signal. The INN pin is grounded through the 220K resistor and 103 capacitor. The BYPASS pin is grounded after passing through the 10UF capacitor and the 104 capacitor in parallel. The VDD pin is connected to VCC power, and the GND pin and the EPAD pin are directly grounded. The output end VOP pin and the VON pin are connected with the anode and the cathode of the loudspeaker through magnetic beads with the model of FBMA-11-16008-601T, and the anode and the cathode of the loudspeaker are grounded through a 102 capacitor.

The audio signal amplifier U2 is successfully amplified by adopting an audio set with the model LM386M, and a sampling resistor with the diameter of 0.1R is connected in series between the negative electrode of the loudspeaker and the VON pin of the NS 4110B. The positive input pin and the negative input pin of the LM386M are respectively connected with two ends of the sampling resistor through a 1K resistor. The gain pin and the gain setting pin are connected through a 10UF/10V capacitor and a 680R resistor. The power pin is connected with the VCC power supply, the grounding pin is directly grounded, and the bypass pin is grounded through a 104 capacitor. The output pin is connected with a C_SPK_COLL pin of the driving component through a 5.1K resistor, and is grounded through a 474 capacitor and a 10R resistor; the C_SPK_COLL pin is connected to ground through a 101 capacitor.

The driving circuit of the automobile alarm sounding unit provided by the utility model has the following working principle:

the audio output pin C_SPK_OUT of the driving component is subjected to high-pass filtering by a third capacitor C3 and a second resistor R2 and then is sent to a class D audio amplifier U1;

after being amplified by the class D audio amplifier U1, the audio control signal is connected to a loudspeaker through a first magnetic bead L1, a fourth capacitor C4, a second magnetic bead L2 and a sixth capacitor C6 output filter;

the output current of the loudspeaker is acquired into a millivolt signal through a sampling resistor R4, amplified through an audio signal amplifier U2, and subjected to low-pass filtering through a sixth resistor R6 and an eighth capacitor C8 to form C_SPK_COLL which is connected to a driving component;

the alarm sound can generate different frequencies and tones through driving components, and the circuit can be used for alarm sound in different scenes, and is convenient and flexible;

when the loudspeaker is disconnected, the C_SPK_COLL pin does not output, and the driving component can judge through the feedback signal of the S_SPK_COLL pin, so that the system performs disconnection identification;

when the loudspeaker is short-circuited, the assignment of the output signal of the C_SPK_COLL pin is far greater than that of a normal signal, so that the system performs short-circuit identification, and the output of the amplifier is closed through the control pin C_SPK_CTRL of the class D amplifier U1;

when the alarm sound can not be normally sent out due to the damage of a line or a loudspeaker, the signal output of the C_SPK_COLL pin is abnormal, and the driving component is identified through the signal fed back by the C_SPK_COLL pin to judge whether the alarm sound is abnormal or not.

In conclusion, the driving scheme of the alarm sounding unit provided by the utility model has a reliability review scheme, so that the convenience of circuit application and debugging is improved, the functions of speaker fault identification and alarm sounding abnormality detection are also realized, the safety guarantee of the whole operation process of the alarm sounding unit is realized, and the use safety of a system and a user is greatly improved.

The present utility model is not limited to the above embodiments, and those skilled in the art can implement the present utility model in various other embodiments according to the examples and the disclosure of the drawings, so that the design of the present utility model is simply changed or modified while adopting the design structure and concept of the present utility model, and the present utility model falls within the scope of protection.

Claims

1. The automobile alarm sounding unit driving circuit is connected with the driving component and is characterized by comprising a sounding driving circuit, a sounding unit and a sounding rechecking circuit;

2. The automotive alert sound unit driving circuit of claim 1, wherein the sound driving circuit includes a high pass filter circuit; the driving component is connected with the class D amplifier U1 through the high-pass filter circuit;

3. The automobile alarm sounding unit driving circuit according to claim 1, wherein the sounding review circuit includes a low-pass filter circuit, the low-pass filter circuit being disposed between the audio signal amplifier U2 and the driving component;

4. The automobile alarm sounding unit driving circuit of claim 1, wherein the class D amplifier U1 is further provided with an EPAD pin, the EPAD pin being directly grounded.