CN220105784U - Buzzer circuit - Google Patents
Buzzer circuit Download PDFInfo
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- CN220105784U CN220105784U CN202321679610.XU CN202321679610U CN220105784U CN 220105784 U CN220105784 U CN 220105784U CN 202321679610 U CN202321679610 U CN 202321679610U CN 220105784 U CN220105784 U CN 220105784U
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- 230000002035 prolonged effect Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
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- 238000012986 modification Methods 0.000 description 2
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- 230000002457 bidirectional effect Effects 0.000 description 1
- 210000005069 ears Anatomy 0.000 description 1
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Abstract
The utility model provides a buzzer circuit, comprising: the driving circuit comprises a signal providing unit, a first switching unit, a second switching unit, a driving voltage providing unit and a buzzer; the first switch unit is respectively and electrically connected with the signal providing unit, the second switch unit and the buzzer; the buzzer is also electrically connected with the second switch unit and the driving voltage supply unit respectively; the signal providing unit provides PWM driving signals; the driving voltage supply unit supplies driving voltage to the buzzer; the first switching unit outputs a first signal that amplifies and inverts the PWM driving signal; the second switch unit outputs a second signal which amplifies the PWM driving signal and is in phase; the buzzer is driven by the alternating current square wave obtained by superposition of the driving voltage, the first signal and the second signal to perform buzzing vibration. The utility model prolongs the service life through alternating current square wave driving, improves the maximum volume, has simple circuit design and reduces the cost, and generates different tone sounds through adjusting the duty ratio and the frequency of the PWM driving signal.
Description
Technical Field
The utility model relates to the technical field of electronic circuits, in particular to a buzzer circuit.
Background
Currently, buzzer circuits suffer from at least one of the following drawbacks:
(1) The buzzer driving signal is unidirectional, so that the sound cannot be exerted to the maximum.
(2) The adopted H-bridge driving scheme is too complex, and the consumed CPU (central processing unit) resources are too much, namely, a MCU (micro control unit) multipath PWM (pulse width modulation) port is occupied, so that the cost is increased.
(3) Because one end of the buzzer is directly connected with the signal providing unit, the highest voltage upper limit (generally not exceeding 5 volts) which can be provided by the voltage providing unit is limited, namely the maximum volume of the buzzer is limited.
(4) When the buzzer stops, the PWM port will maintain a fixed level, the buzzer will bear a direct current voltage, the direct current voltage will damage the piezoelectric buzzer with time, and the volume will decay rapidly or even thoroughly with the increase of the using time.
Disclosure of Invention
The technical problem to be solved by the utility model is to provide a buzzer circuit for overcoming the defects in the prior art.
The utility model solves the technical problems by the following technical scheme:
the utility model provides a buzzer circuit, comprising: the driving circuit comprises a signal providing unit, a first switching unit, a second switching unit, a driving voltage providing unit and a buzzer;
the first switch unit is respectively and electrically connected with the signal providing unit, the second switch unit and the buzzer;
the buzzer is also electrically connected with the second switch unit and the driving voltage supply unit respectively;
the signal providing unit is used for providing PWM driving signals;
the driving voltage supply unit is used for supplying driving voltage to the buzzer;
the first switching unit is used for outputting a first signal which amplifies and inverts the PWM driving signal;
the second switching unit is used for outputting a second signal which amplifies the PWM driving signal and is in phase;
the buzzer is used for performing buzzing vibration under the driving of the alternating current square wave obtained by superposition of the driving voltage, the first signal and the second signal.
Preferably, the driving voltage supply unit includes a first resistor and a second resistor;
the first end of the first resistor is electrically connected with the power supply voltage and the first end of the second resistor respectively, the second end of the first resistor is electrically connected with the first end of the buzzer and the output end of the first switch unit respectively, and the second end of the second resistor is electrically connected with the second end of the buzzer and the output end of the second switch unit respectively.
Preferably, the first switch unit includes a third resistor and a first NPN triode;
the first end of the third resistor is electrically connected with the output end of the signal providing unit, the second end of the third resistor is electrically connected with the base electrode of the first NPN triode, the emitter electrode of the first NPN triode is grounded, and the collector electrode of the first NPN triode is used as the output end of the first switch unit.
Preferably, the second switch unit includes a fourth resistor and a second NPN triode;
the first end of the fourth resistor is electrically connected with the output end of the first switch unit, the second end of the fourth resistor is electrically connected with the base electrode of the second NPN triode, the emitter electrode of the second NPN triode is grounded, and the collector electrode of the second NPN triode is used as the output end of the second switch unit.
Preferably, the ratio of the resistance value of the fourth resistor to the resistance value of the first resistor is greater than a preset ratio threshold.
Preferably, the ratio threshold is set to 10.
Preferably, the resistance value of the first resistor is the same as the resistance value of the second resistor.
Preferably, the duty cycle and frequency of the PWM drive signal are adjustable.
Preferably, when no buzzer is required, setting the duty ratio of the PWM driving signal to be 50%, and setting the frequency of the PWM driving signal to be greater than a preset frequency threshold;
wherein the frequency threshold exceeds an audible frequency of the human ear.
Preferably, the first and second switching units amplify a peak value of the PWM driving signal to the power supply voltage.
The utility model has the positive progress effects that: the first signal for amplifying and inverting the PWM driving signal is output through the first switch unit, the second signal for amplifying and inverting the PWM driving signal is output through the second switch unit, the buzzer is driven by the alternating current square wave obtained by superposition of the driving voltage, the first signal and the second signal to perform buzzing vibration, the long-term maintenance of the direct current voltage at the two ends of the buzzer is avoided, the service life of the buzzer is prolonged, meanwhile, the maximum sound exertion can be realized through alternating current driving, the maximum buzzing volume is improved, the circuit design is simple, the consumed CPU resource is reduced, the cost is reduced, and the sounds with different tones can be generated by adjusting the duty ratio and the frequency of the PWM driving signal.
Drawings
Fig. 1 is a schematic diagram of a buzzer circuit according to a preferred embodiment of the present utility model.
Fig. 2 is a circuit configuration diagram of a buzzer circuit according to a preferred embodiment of the present utility model.
Detailed Description
The present utility model will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments are shown.
The present embodiment provides a buzzer circuit, referring to fig. 1, the buzzer circuit includes: a signal providing unit 1, a first switching unit 2, a second switching unit 3, a driving voltage providing unit 4 and a buzzer BUZ1.
The first switching unit 2 is electrically connected to the signal providing unit 1, the second switching unit 3, and the buzzer BUZ1, respectively.
The buzzer BUZ1 is also electrically connected to the second switching unit 3 and the driving voltage supply unit 4, respectively.
The signal providing unit 1 is used for providing a PWM driving signal.
The driving voltage supply unit 4 is used for supplying a driving voltage to the buzzer BUZ1.
The first switching unit 2 is for outputting a first signal that amplifies and inverts the PWM driving signal.
The second switching unit 3 is for outputting a second signal that amplifies the PWM driving signal and is in phase.
The buzzer BUZ1 is used for performing buzzing vibration under the driving of alternating current square waves obtained by superposition of the driving voltage, the first signal and the second signal.
When the PWM driving signal is a high-low level square wave with 50%, the two ends of the buzzer will obtain pure ac square waves with ±driving voltage (for example, ±12v), so that bidirectional voltage driving of the buzzer is realized, the effective driving voltage (ac) of the buzzer is increased by 1 time, and the volume is larger under the same power supply voltage.
The output ends of the first switch unit and the second switch unit are respectively connected with two ends of the buzzer, the driving voltage supply unit is also respectively connected with two ends of the buzzer, and the driving voltage of the buzzer can be conveniently changed by changing the voltage supplied by the driving voltage supply unit.
The signal providing unit may be implemented by the prior art and will not be described here in detail.
According to the embodiment, the first signal for amplifying and inverting the PWM driving signal is output through the first switch unit, the second signal for amplifying and inverting the PWM driving signal is output through the second switch unit, the buzzer is driven by the alternating current square wave obtained by superposition of the driving voltage, the first signal and the second signal to perform buzzing vibration, the long-term maintenance of the direct current voltage at the two ends of the buzzer is avoided, the service life of the buzzer is prolonged, meanwhile, the maximum sound exertion can be realized through alternating current driving, the maximum buzzing volume is improved, the circuit design is simple, the consumed CPU resource is reduced, the cost is reduced, and the sounds with different tones can be generated by adjusting the duty ratio and the frequency of the PWM driving signal.
In particular, referring to fig. 2, the driving voltage supply unit 4 includes a first resistor R1 and a second resistor R2.
The first end of the first resistor R1 is respectively and electrically connected with the power supply voltage and the first end of the second resistor R2, the second end of the first resistor R1 is respectively and electrically connected with the first end of the buzzer BUZ1 and the output end of the first switch unit 2, and the second end of the second resistor R2 is respectively and electrically connected with the second end of the buzzer BUZ1 and the output end of the second switch unit 3.
The power supply voltage in fig. 2 is 12V (volts), and may be set to other voltage values; the two arrow dashed lines represent paths of current, only one of which has current at the same time, and the arrow indicates the flow direction of current.
In specific implementation, referring to fig. 2, the first switching unit 2 includes a third resistor R3 and a first NPN transistor Q1.
The first end of the third resistor R3 is electrically connected with the output end of the signal providing unit 1, the second end of the third resistor R3 is electrically connected with the base electrode of the first NPN triode Q1, the emitter electrode of the first NPN triode Q1 is grounded, and the collector electrode of the first NPN triode Q1 is the output end of the first switch unit 2.
In specific implementation, referring to fig. 2, the second switching unit 3 includes a fourth resistor R4 and a second NPN transistor Q2.
The first end of the fourth resistor R4 is electrically connected with the output end of the first switch unit 2, the second end of the fourth resistor R4 is electrically connected with the base electrode of the second NPN triode Q2, the emitter electrode of the second NPN triode Q2 is grounded, and the collector electrode of the second NPN triode Q2 is the output end of the second switch unit 3.
In specific implementation, the ratio of the resistance of the fourth resistor R4 to the resistance of the first resistor R1 is greater than a preset ratio threshold.
The resistance of the fourth resistor R4 is far greater than that of the first resistor R1, so that the resistance of the first resistor R1 is negligible compared with that of the fourth resistor R4, and the driving voltage obtained by the buzzer is substantially the same as the power supply voltage.
In particular, the ratio threshold is set to 10.
Wherein the ratio threshold may be set to 10 or above 10.
In specific implementation, the resistance value of the first resistor R1 is the same as the resistance value of the second resistor R2.
In particular implementations, the duty cycle and frequency of the PWM drive signal may be adjustable.
When the device needs to buzzing, the signal providing unit can provide PWM driving signals with set frequency and duty ratio so as to generate sounds with different tones and even play voices.
When the equipment does not need to be buzzed, the signal providing unit can provide square waves with the specific fixed frequency and the duty ratio of 50%, so that the situation that the ears of people are audible is avoided, the situation that the direct current voltage is clamped at two ends of the buzzer for a long time when the buzzing is not needed is avoided, the defect that the service life of the buzzer is shortened is avoided, the buzzer hardly bears the direct current voltage at any time, and the service life of the buzzer is greatly prolonged.
In specific implementation, when the buzzer is not needed, the duty ratio of the PWM driving signal is set to be 50%, and the frequency of the PWM driving signal is set to be larger than a preset frequency threshold.
Wherein the frequency threshold exceeds the audible frequency of the human ear.
Wherein the frequency threshold may be set according to actual needs, for example 20kHz (kilohertz).
In particular, the first switching unit 2 and the second switching unit 3 amplify the peak value of the PWM driving signal to the power supply voltage.
While specific embodiments of the utility model have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and the scope of the utility model is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the utility model, but such changes and modifications fall within the scope of the utility model.
Claims (10)
1. A buzzer circuit, comprising: the driving circuit comprises a signal providing unit, a first switching unit, a second switching unit, a driving voltage providing unit and a buzzer;
the first switch unit is respectively and electrically connected with the signal providing unit, the second switch unit and the buzzer;
the buzzer is also electrically connected with the second switch unit and the driving voltage supply unit respectively;
the signal providing unit is used for providing PWM driving signals;
the driving voltage supply unit is used for supplying driving voltage to the buzzer;
the first switching unit is used for outputting a first signal which amplifies and inverts the PWM driving signal;
the second switching unit is used for outputting a second signal which amplifies the PWM driving signal and is in phase;
the buzzer is used for performing buzzing vibration under the driving of the alternating current square wave obtained by superposition of the driving voltage, the first signal and the second signal.
2. The buzzer circuit of claim 1, wherein the driving voltage providing unit includes a first resistor and a second resistor;
the first end of the first resistor is electrically connected with the power supply voltage and the first end of the second resistor respectively, the second end of the first resistor is electrically connected with the first end of the buzzer and the output end of the first switch unit respectively, and the second end of the second resistor is electrically connected with the second end of the buzzer and the output end of the second switch unit respectively.
3. The buzzer circuit of claim 2, wherein the first switching unit includes a third resistor and a first NPN transistor;
the first end of the third resistor is electrically connected with the output end of the signal providing unit, the second end of the third resistor is electrically connected with the base electrode of the first NPN triode, the emitter electrode of the first NPN triode is grounded, and the collector electrode of the first NPN triode is used as the output end of the first switch unit.
4. The buzzer circuit of claim 2, wherein the second switching unit includes a fourth resistor and a second NPN triode;
the first end of the fourth resistor is electrically connected with the output end of the first switch unit, the second end of the fourth resistor is electrically connected with the base electrode of the second NPN triode, the emitter electrode of the second NPN triode is grounded, and the collector electrode of the second NPN triode is used as the output end of the second switch unit.
5. The buzzer circuit of claim 4, wherein the ratio of the resistance of the fourth resistor to the resistance of the first resistor is greater than a predetermined ratio threshold.
6. The buzzer circuit of claim 5, wherein the ratio threshold is set to 10.
7. A buzzer circuit in accordance with claim 2, wherein the first resistor has the same resistance as the second resistor.
8. A buzzer circuit in accordance with claim 1, wherein the duty cycle and frequency of the PWM drive signal are adjustable.
9. The buzzer circuit of claim 8, wherein when no buzzing is required, the duty cycle of the PWM drive signal is set to 50%, and the frequency of the PWM drive signal is set to be greater than a preset frequency threshold;
wherein the frequency threshold exceeds an audible frequency of the human ear.
10. The buzzer circuit of claim 2, wherein the first switching unit and the second switching unit amplify a peak value of the PWM driving signal to the power supply voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321679610.XU CN220105784U (en) | 2023-06-29 | 2023-06-29 | Buzzer circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321679610.XU CN220105784U (en) | 2023-06-29 | 2023-06-29 | Buzzer circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220105784U true CN220105784U (en) | 2023-11-28 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202321679610.XU Active CN220105784U (en) | 2023-06-29 | 2023-06-29 | Buzzer circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220105784U (en) |
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2023
- 2023-06-29 CN CN202321679610.XU patent/CN220105784U/en active Active
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