Special driving circuit for piezoelectric horn of electric vehicle

Abstract

The utility model relates to a special drive circuit for a piezoelectric horn of an electric vehicle, which comprises a reference voltage stabilization source, a memory, an oscillator, a time sequence, a central processing unit (CPU), a pulse width modulation (PWM) signal, an input buffer, a level shifter and a piezoelectric horn drive circuit, and the reference voltage stabilization source provides reference voltage for the memory, the oscillator, the time sequence, the CPU, the PWM signal and the input buffer. And the memory, the oscillator, the time sequence, the PWM signal and the input buffer are respectively connected with the CPU. And the level transfer module is connected with the piezoelectric horn driving circuit. The piezoelectric horn driving circuit is provided with two output ends. The utility model has the advantages of wide working voltage and diversified output sound effects, can realize single-end or double-end driving application, and is suitable for various electric two-wheeled vehicles and tricycles.

Description

TECHNICAL FIELD

[0001] The utility model relates to electric car piezoelectric horn field, specifically discloses a special driving circuit of electric car piezoelectric horn. BACKGROUND

[0002] With the popularity of electric two-wheeled vehicles and three-wheeled vehicles, pedestrian safety is increasingly valued, and electric vehicles need to alert pedestrians and other road users through sound prompts. The existing electric vehicle prompting system mostly uses simple mechanical vibration horns or uses multiple buzzer combinations as prompt sounds, which are single-function, have many devices and cannot meet the diversified sound effect needs of remote control, anti-theft alarm, steering prompt, etc. Therefore, there is an urgent need for an efficient, flexible, special and built-in multi-sound effect driving circuit to provide various sound effect prompts with piezoelectric horns to meet the safety of electric vehicles. SUMMARY

[0003] The utility model aims at: provide a kind of special driving circuit of electric car piezoelectric horn for solving above-mentioned problem, working voltage is wide, output sound effect is diversified, can realize single-end or double-end driving application.

[0004] The utility model adopts the technical scheme as follows:

[0005] A special driving circuit of electric car piezoelectric horn, comprising a reference voltage source, a memory, an oscillator and a time sequence, a central processing unit CPU, a PWM signal, an input buffer, a level shift and a piezoelectric horn driving circuit, the reference voltage source provides a reference voltage for the memory, the oscillator and the time sequence, the central processing unit CPU, the PWM signal and the input buffer;The memory, the oscillator and the time sequence, the PWM signal and the input buffer are connected with the central processing unit CPU respectively;The level shift module is connected with the piezoelectric horn driving circuit;The piezoelectric horn driving circuit is provided with two output terminals OUT1 and OUT2.

[0006] Further, the reference voltage source has a temperature compensation circuit, and the reference voltage source provides an external power supply voltage after voltage stabilization to each module and leads out a voltage detection pin VR.

[0007] Further, the memory includes a program memory and a data memory.

[0008] Further, the PWM signal module is controlled by the central processing unit CPU, and can output multiple PWM signals, while leading out a PWM pin for signal detection when the circuit is applied.

[0009] Further, the level shift module converts the PWM signal into a control signal of the piezoelectric horn driving circuit.

[0010] Furthermore, the piezoelectric horn driving circuit is an H-bridge driving mode with two output pins OUT1 and OUT2. The two output pins output PWM square waves with a phase difference of 180°. The output pins are directly connected to the two ends of the piezoelectric horn, which can obtain a horn driving voltage of twice the external power supply voltage.

[0011] Furthermore, the input buffer has three input pins I1, I2, and I3. By setting the high and low levels of the input pins, the circuit can output a total of eight different sound effect PWM square waves.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0013] This utility model has a wide operating voltage range and diverse output sound effects. It can realize single-end or dual-end drive applications and can simultaneously meet the sound effect requirements of electric vehicle pedestrian warning horns, turn signal sounds, anti-theft alarm sounds, overspeed warning sounds, and remote control feedback sounds. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the principle of this utility model;

[0015] Figure 2 This is a schematic diagram symbol for this utility model;

[0016] Figure 3 This is a schematic diagram illustrating the dual-end application principle of this utility model;

[0017] Figure 4 This is a schematic diagram of the single-end application principle of this utility model.

[0018] In the diagram, 1. Reference voltage regulator; 2. Memory; 3. Oscillator and timing; 4. Central processing unit (CPU); 5. PWM signal; 6. Input buffer; 7. Level shifter; 8. Piezoelectric horn driver circuit. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0020] like Figures 1-4 As shown, a dedicated drive circuit for an electric vehicle piezoelectric horn includes eight functional modules: a reference voltage regulator 1, a memory 2, an oscillator and timing mechanism 3, a central processing unit (CPU) 4, a PWM signal 5, an input buffer 6, a level shifter 7, and a piezoelectric horn drive circuit 8. The reference voltage regulator 1 provides a reference voltage to the memory 2, oscillator and timing mechanism 3, CPU 4, PWM signal 5, and input buffer 6. The memory 2, oscillator and timing mechanism 3, PWM signal 5, and input buffer 6 are all connected to the CPU 4.

[0021] The memory 2 includes program memory and data memory, for storing data or programs related to the audio signal, including specifically the waveform, frequency, amplitude and other parameters of the audio signal, as well as instructions or programs for controlling the operation of the piezoelectric horn.

[0022] The role of the memory is to provide these data or programs when needed, so that the piezoelectric horn can emit sound in a predetermined manner.

[0023] The oscillator and timing 3 are used to generate an oscillation signal and to process the timing relationship of the signal.

[0024] The level shift 7 converts the PWM signal into two square wave signals with a phase difference of 180° for controlling the piezoelectric horn drive circuit 8. The piezoelectric horn drive circuit 8 adopts an H-bridge drive mode, provided with two output pins OUT1 and OUT2, which are directly connected to both ends of the piezoelectric horn, and can obtain a horn drive voltage of 2 times the external power supply voltage.

[0025] The reference voltage source 1 is electrically connected with a temperature compensation circuit, which includes a thermistor, an operational amplifier and an adjustable resistor. The thermistor is connected in series at the input or output end of the reference voltage source 1, and the change of its resistance value is used to reflect the change of temperature. The resistance value of the thermistor is converted into a voltage signal by the operational amplifier, and is amplified and processed. The operational amplifier receives the voltage signal from the temperature sensor, and amplifies and compares it. According to the comparison result, the operational amplifier outputs a control signal for adjusting the output voltage of the reference voltage source 1. The output voltage of the reference voltage source 1 is adjusted by the adjustable resistor. One end of the adjustable resistor is connected to the output end of the reference voltage source 1, and the other end is grounded or connected to other circuit elements. By adjusting the resistance value of the adjustable resistor, the output voltage of the reference voltage source 1 can be changed, thereby achieving temperature compensation.

[0026] As shown in Figure 2 The circuit is provided with a total of 10 pins, namely the power supply end VDD, two output ends OUT1 and OUT2, the power ground GND and the digital ground VSS, the PWM signal 5 detection end PWM, the reference voltage source 1 voltage detection end VR, and three sound effect selection ends I1, I2 and I3. By setting the high and low levels of I1, I2 and I3, the circuit outputs a total of one mute state and seven drive square waves of sound effects, including three types of iron horn simulation sound, turning prompt sound, anti-theft alarm sound, and remote locking and unlocking sound.

[0027] As shown in Figures 3-4The utility model discloses a simple circuit, the input power range is wide 12V~72V, and the piezoelectric horn of driving can select single-end application and double-end application, when single-end application, the piezoelectric horn of driving drive voltage Vp-p=VDD, when double-end application, the piezoelectric horn of driving drive voltage Vp-p=2*VDD, can make the horn emit higher sound pressure.

[0028] The above merely describes the preferred embodiments of the utility model and is not intended to limit the utility model, and any modification, equivalent replacement and improvement within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A dedicated drive circuit for piezoelectric horns in electric vehicles, characterized in that: It includes a reference voltage regulator, memory, oscillator and timing, central processing unit (CPU), PWM signal, input buffer, level shifter and piezoelectric horn driver circuit; The reference voltage source provides a reference voltage for the memory, oscillator and timing, central processing unit (CPU), PWM signal, and input buffer. The memory, oscillator, timing signal, PWM signal, and input buffer are electrically connected to the central processing unit (CPU). The level shifter is electrically connected to the piezoelectric horn driver circuit, which has two output terminals.

2. The dedicated drive circuit for electric vehicle piezoelectric horns according to claim 1, characterized in that: The reference voltage source is electrically connected to a temperature compensation circuit.

3. The dedicated drive circuit for electric vehicle piezoelectric horns according to claim 1, characterized in that: The memory includes program memory and data memory.

4. The dedicated drive circuit for electric vehicle piezoelectric horns according to claim 1, characterized in that: The level shift is used to convert the PWM signal into a control signal for the piezoelectric horn driver circuit.

5. The dedicated drive circuit for electric vehicle piezoelectric horns according to claim 1, characterized in that: The piezoelectric horn driving circuit adopts an H-bridge driving mode and has two output pins. The two output pins output driving square waves with a phase difference of 180°, and the two output pins are respectively connected to the two ends of the piezoelectric horn.

6. The dedicated drive circuit for electric vehicle piezoelectric horns according to claim 1, characterized in that: The input buffer has three input pins. By setting the high and low levels of the input pins, the circuit outputs PWM pulses containing different sound effect information.

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