Beautiful sound buzzer circuit

Abstract

The utility model particularly relates to a beautiful sound buzzer circuit, which comprises a buzzer BUZ1 and a single chip microcomputer, a high-frequency drive circuit is connected to a first end of the buzzer BUZ1, a low-frequency drive circuit is connected to a second end of the buzzer BUZ1, a BuzPow end of the single chip microcomputer is connected with the high-frequency drive circuit, a BuzHz end of the single chip microcomputer is connected with the low-frequency drive circuit, and the buzzer BUZ1 is connected with the buzzer BUZ1. And the low-frequency driving circuit and the high-frequency driving circuit are connected through a second resistor R2. According to the structure, the buzzer BUZ1 is driven through the high-frequency driving circuit and the low-frequency driving circuit, the low-frequency driving circuit is used for implementing voltage reduction to gradually reduce so as to generate a gradually-weak sound, and the single chip microcomputer is matched to control the on-off time of the BuzzPow end so as to control the length of the buzzing sound. And the single-chip microcomputer controls the frequency of the BuzzHz end so as to control the musical scale of the sound, so that music sound or melodious ding-dong sound can be made, and the user experience is improved.

Description

Technical Field

[0001] The utility model specifically relates to a beautiful-sound buzzer circuit. Background Art

[0002] A buzzer is an electronic sounder with an integrated structure, powered by DC voltage. It is widely used as a sound-generating device in electronic products such as computers, printers, copiers, alarms, electronic toys, automotive electronic equipment, telephones, timers, etc.

[0003] For example, the name of an invention application is disclosed as follows: A novel buzzer circuit, with application number CN201710279607.1, comprising a step-down circuit, a DC voltage source, a microcontroller and a first switch tube, the buzzer is connected to the microcontroller through the first switch tube, and is characterized in that it also comprises a second switch tube, a third switch tube, a fourth switch tube and a first capacitor, the control end of the first switch tube is connected to the PWM signal output end of the microcontroller and is grounded through a resistor, the first end of the first switch tube is connected to one end of the buzzer, and the second end of the first switch tube is grounded; the control end of the second switch tube is connected to the I / O port of the microcontroller, the first end of the second switch tube is connected to the control end of the third switch tube, and the second end of the second switch tube is grounded; the first end of the third switch tube is grounded through a resistor, the first end of the third switch tube is connected to the control end of the third switch tube, and the second end of the third switch tube is grounded; the first end of the third switch tube is grounded through a resistor, and the second end of the third switch tube is connected to the DC voltage source and the control end of the third opening tube through a resistor respectively; the control end of the fourth switch tube is connected to the first end of the third switch tube, and is grounded through the first capacitor and the resistor, the first end of the fourth switch tube is connected to the second end of the third switch tube, and the second end of the fourth switch tube is connected to the other end of the buzzer.

[0004] The buzzer circuit mainly solves the problem of low power consumption of the buzzer. By using a resistor to reduce the voltage, the AC power can be converted into AC and DC, thereby improving the stability of the product. However, the buzzer circuit has only one frequency, and there is no gradual in and out, the sound is relatively stiff and not pleasant enough. In order to increase the user experience, this structural application gradually requires the buzzer to be able to make musical sounds or pleasant ding-dong sounds, thus producing a beautiful buzzer circuit. Summary of the invention

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to provide a beautiful buzzer circuit that can emit musical sounds or pleasant ding-dong sounds to increase user experience.

[0006] According to the utility model, a beautiful sound buzzer circuit includes a buzzer BUZ1 and a single-chip microcomputer. 1 of the buzzer BUZ1 is connected to a high-frequency drive circuit, 2 of the buzzer BUZ1 is connected to a low-frequency drive circuit, the BuzzPow end of the single-chip microcomputer is connected to the high-frequency drive circuit, the BuzzHz end of the single-chip microcomputer is connected to the low-frequency drive circuit, and the low-frequency drive circuit and the high-frequency drive circuit are connected via a second resistor R2.

[0007] Specifically, the low-frequency drive circuit includes a first transistor Q1, a second transistor Q2 and an electrolytic capacitor EC1, the BuzzPow end of the single-chip computer is connected to the base of the second transistor Q2, the collector of the second transistor Q2 is connected to the base of the first transistor Q1, the emitter of the first transistor Q1 is connected to a +12V DC voltage, the collector of the first transistor Q1 is connected to the positive electrode of the electrolytic capacitor EC1, the negative electrode of the electrolytic capacitor EC1 is connected to the ground terminal GND, and the collector of the first transistor Q1 is connected to the second resistor R2.

[0008] Specifically, the BuzzPow terminal of the single chip is connected to the base of the second transistor Q2 via an eighth resistor R8, and a ninth resistor R9 is connected in parallel between the base of the second transistor Q2 and the emitter of the second transistor Q2.

[0009] Specifically, the collector of the second transistor Q2 and the base of the first transistor Q1 are connected via a fourth resistor R4.

[0010] Specifically, a fifth resistor R5 is connected in parallel between the base of the first transistor Q1 and the emitter of the first transistor Q1.

[0011] Specifically, the collector of the first transistor Q1 is connected to the positive electrode of the electrolytic capacitor EC1 via a first resistor R1.

[0012] Specifically, the third transistor Q3 is an NPN transistor.

[0013] Specifically, the high-frequency driving circuit includes a third transistor Q3, the BuzzHz terminal of the single-chip microcomputer is connected to the base of the third transistor Q3, the pin 1 of the buzzer BUZ1 is connected to the collector of the third transistor Q3, and the emitter of the third transistor Q3 is connected to GND.

[0014] Specifically, the BuzzHz end of the microcontroller is connected to the base of the third transistor Q3 through the seventh resistor R7, the third resistor R3 is passed between the 1st pin of the buzzer BUZ1 and the collector of the third transistor Q3, and the sixth resistor R6 is connected in parallel between the base of the third transistor Q3 and the emitter of the third transistor Q3.

[0015] Specifically, the second transistor Q2 is an NPN transistor, and the first transistor Q1 is a PNP transistor.

[0016] The beneficial effects of the utility model are as follows: the structure is driven by the buzzer BUZ1 through a high-frequency driving circuit and a low-frequency driving circuit, and the voltage is gradually reduced by the low-frequency driving circuit to produce a gradually weakening sound. The on-off time of the BuzzPow end is controlled by the single-chip microcomputer to control the length of the buzzing sound, and the frequency of the BuzzHz end is controlled by the single-chip microcomputer to control the scale of the sound, so that music or pleasant ding-dong sounds can be emitted, thereby increasing the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 It is a circuit diagram of the utility model. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0020] Reference below Figure 1 A beautiful-sounding buzzer circuit is described according to an embodiment of the utility model, including a buzzer BUZ1 and a single-chip microcomputer. 1 of the buzzer BUZ1 is connected to a high-frequency drive circuit, 2 of the buzzer BUZ1 is connected to a low-frequency drive circuit, the BuzzPow end of the single-chip microcomputer is connected to the high-frequency drive circuit, the BuzzHz end of the single-chip microcomputer is connected to the low-frequency drive circuit, and the low-frequency drive circuit and the high-frequency drive circuit are connected via a second resistor R2.

[0021] This structure drives the buzzer BUZ1 through a high-frequency driving circuit and a low-frequency driving circuit. The low-frequency driving circuit is used to implement a voltage drop to gradually reduce the voltage and produce a gradually weakening sound. The single-chip microcomputer controls the on-off time of the BuzzPow end to control the length of the buzzing sound, and the single-chip microcomputer controls the frequency of the BuzzHz end to control the scale of the sound. It can produce music or pleasant ding-dong sounds, thereby increasing the user experience.

[0022] The low-frequency driving circuit of this circuit includes a first transistor Q1, a second transistor Q2 and an electrolytic capacitor EC1, the BuzzPow terminal of the single-chip microcomputer is connected to the base of the second transistor Q2, the collector of the second transistor Q2 is connected to the base of the first transistor Q1, the emitter of the first transistor Q1 is connected to a +12V DC voltage, the collector of the first transistor Q1 is connected to the positive electrode of the electrolytic capacitor EC1, the negative electrode of the electrolytic capacitor EC1 is connected to the ground terminal GND, and the collector of the first transistor Q1 is connected to the second resistor R2. The BuzzPow terminal of the single-chip microcomputer is connected to the base of the second transistor Q2 through an eighth resistor R8, and a ninth resistor R9 is connected in parallel between the base of the second transistor Q2 and the emitter of the second transistor Q2. The collector of the second transistor Q2 is connected to the base of the first transistor Q1 through a fourth resistor R4. A fifth resistor R5 is connected in parallel between the base of the first transistor Q1 and the emitter of the first transistor Q1. In this circuit, the collector of the first transistor Q1 is connected to the positive electrode of the electrolytic capacitor EC1 through the first resistor R1. The third transistor Q3 is an NPN transistor. The high-frequency driving circuit in this circuit includes the third transistor Q3, the BuzzHz end of the single-chip microcomputer is connected to the base of the third transistor Q3, the 1st pin of the buzzer BUZ1 is connected to the collector of the third transistor Q3, and the emitter of the third transistor Q3 is connected to GND. The BuzzHz end of the single-chip microcomputer in this circuit is connected to the base of the third transistor Q3 through the seventh resistor R7, the 1st pin of the buzzer BUZ1 and the collector of the third transistor Q3 are connected through the third resistor R3, and the base of the third transistor Q3 and the emitter of the third transistor Q3 are connected in parallel with the sixth resistor R6. In this circuit, the second transistor Q2 is an NPN transistor, and the first transistor Q1 is a PNP transistor.

[0023] The working principle of this circuit is as follows:

[0024] When the BuzzPow terminal of the single-chip microcomputer outputs a high level, the second transistor Q2 is turned on, the base of the first transistor Q1 is pulled low, and the first transistor Q1 is turned on. At this time, the electrolytic capacitor EC1 starts to charge, and the collector voltage of the first Q1 to ground is 12V. At this time, a square wave of the corresponding frequency is output at the BuzzHz terminal of the single-chip microcomputer, and the third transistor Q3 is continuously turned on and off, and a square wave with the same frequency and opposite phase to the BuzzHz terminal is formed at the collector of the third transistor Q3, and the buzzer BUZ1 starts to buzz.

[0025] When the BuzzPow terminal of the single-chip microcomputer outputs a low level, the second transistor Q2 is turned off, and the first transistor Q1 is also turned off. At this time, since the BuzzHz terminal of the single-chip microcomputer is still outputting a square wave, and the voltage of the electrolytic capacitor EC1 is 12V, the electrolytic capacitor EC1 is discharged to the ground through the first resistor R1, the second resistor R2 and the third resistor R3, and the sound of the buzzer BUZ1 will gradually decrease as the voltage of the electrolytic capacitor EC1 decreases, producing a gradually weakening sound, and the beautiful sound comes from this. The on and off time of the BuzzPow terminal controls the length of the buzzing sound, and the frequency of the BuzzHz terminal controls the scale of the sound, which can be adjusted in the single-chip microcomputer. The size of the electrolytic capacitor EC1 and the size of the first resistor R1, the second resistor R2 and the third resistor R3 control the discharge time, that is, the duration of the tail sound.

[0026] The sixth resistor R6 and the ninth resistor R9 have two main functions: 1. When the base control level changes from high to low, the base can be pulled down faster, and the NPN transistor can be cut off faster and more reliably; 2. When the system is just powered on, the base is at a certain low level. Correspondingly, the fifth resistor R5 also has two main functions: when the base control level changes from low to high, the base can be pulled up faster, and the PNP transistor can be cut off faster and more reliably; 2. When the system is just powered on, the base is at a certain high level.

[0027] In addition, the electrolytic capacitor EC1 is selected as 100uF / 25V, the model of the first transistor Q1 is 2S8550, the model of the second transistor Q2 and the third transistor Q3 is 2SA8050, and the resonant frequency of the buzzer BUZ1 is 4KHz.

[0028] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A beautiful buzzer circuit, including a buzzer BUZ1, characterized in that: It also includes a single chip microcomputer, 1 of the buzzer BUZ1 is connected to a high frequency drive circuit, 2 of the buzzer BUZ1 is connected to a low frequency drive circuit, the BuzzPow end of the single chip microcomputer is connected to the high frequency drive circuit, the BuzzHz end of the single chip microcomputer is connected to the low frequency drive circuit, the low frequency drive circuit and the high frequency drive circuit are connected through a second resistor R2, the low frequency drive circuit includes a first transistor Q1, a second transistor Q2 and an electrolytic capacitor EC1, the BuzzPow end of the single chip microcomputer is connected to the base of the second transistor Q2, the collector of the second transistor Q2 is connected to the base of the first transistor Q1, the emitter of the first transistor Q1 is connected to a +12V DC voltage, the collector of the first transistor Q1 is connected to the positive electrode of the electrolytic capacitor EC1, the negative electrode of the electrolytic capacitor EC1 is connected to the ground terminal GND, the collector of the first transistor Q1 is connected to the second resistor R2, The high-frequency driving circuit includes a third transistor Q3, the BuzzHz terminal of the single-chip microcomputer is connected to the base of the third transistor Q3, the pin 1 of the buzzer BUZ1 is connected to the collector of the third transistor Q3, and the emitter of the third transistor Q3 is connected to GND.

2. The beautiful sound buzzer circuit according to claim 1, characterized in that: The BuzzPow terminal of the single chip is connected to the base of the second triode Q2 via an eighth resistor R8, and a ninth resistor R9 is connected in parallel between the base of the second triode Q2 and the emitter of the second triode Q2.

3. The beautiful sound buzzer circuit according to claim 1, characterized in that: The collector of the second transistor Q2 and the base of the first transistor Q1 are connected via a fourth resistor R4.

4. The beautiful sound buzzer circuit according to claim 1, characterized in that: A fifth resistor R5 is connected in parallel between the base of the first transistor Q1 and the emitter of the first transistor Q1 .

5. The beautiful sound buzzer circuit according to claim 1, characterized in that: The collector of the first transistor Q1 is connected to the positive electrode of the electrolytic capacitor EC1 via a first resistor R1.

6. The beautiful buzzer circuit according to claim 1, characterized in that: The third transistor Q3 is an NPN transistor.

7. The beautiful buzzer circuit according to claim 1, characterized in that: The BuzzHz terminal of the single chip is connected to the base of the third transistor Q3 via the seventh resistor R7, the 1st pin of the buzzer BUZ1 and the collector of the third transistor Q3 are connected via the third resistor R3, and the sixth resistor R6 is connected in parallel between the base of the third transistor Q3 and the emitter of the third transistor Q3.

8. The beautiful buzzer circuit according to claim 1, characterized in that: The second transistor Q2 is an NPN transistor, and the first transistor Q1 is a PNP transistor.

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