CN210202074U

CN210202074U - Analog buzzer circuit and electronic equipment

Info

Publication number: CN210202074U
Application number: CN201921516943.4U
Authority: CN
Inventors: Jun He; 何军
Original assignee: GUANGDONG ANJUBAO DIGITAL TECHNOLOGY Co Ltd
Current assignee: GUANGDONG ANJUBAO DIGITAL TECHNOLOGY Co Ltd
Priority date: 2019-09-11
Filing date: 2019-09-11
Publication date: 2020-03-27
Anticipated expiration: 2029-09-11

Abstract

The application provides a simulated buzzer circuit and an electronic device. The analog buzzer circuit includes: the input end is connected with the output end of the controller and used for receiving the square wave with fixed frequency output by the controller; the value of the fixed frequency corresponds to the frequency value of the buzzer to be simulated; and one end of the signal processing circuit is connected with the input end, and the other end of the signal processing circuit is connected with the loudspeaker and is used for enhancing the square wave with the fixed frequency and then inputting the enhanced square wave into the loudspeaker so as to drive the loudspeaker to make the sound with the fixed frequency value. The analog buzzer has simple circuit, can simulate the sounding of the buzzer by using the simple circuit, can replace an active buzzer and a passive buzzer, and solves the problem that a small number of sounding frequencies of the buzzer have deviation (namely uneven quality); on the other hand, the circuit is simple, and the structural space is not limited, so that the applicability of the analog buzzer circuit is improved.

Description

Analog buzzer circuit and electronic equipment

Technical Field

The application relates to the technical field of circuits, in particular to an analog buzzer circuit and electronic equipment.

Background

The traditional buzzer design is that an active buzzer or a passive buzzer is directly selected for use, the active buzzer and the passive buzzer mainly depend on a current to drive a buzzer to sound, the active buzzer and the passive buzzer are designed by hardware, and due to the fact that hardware parameters can deviate, defective products exist in a certain proportion when a factory leaves a factory.

Moreover, the buzzer is large in size and is not suitable for ultrathin products with limited structures.

Therefore, the traditional buzzer is limited in application range and not strong in applicability; uneven quality and poor stability.

SUMMERY OF THE UTILITY MODEL

An object of the embodiment of the application is to provide an analog buzzer circuit and an electronic device, so as to improve the problems of weak applicability and poor stability of a traditional buzzer.

In a first aspect, an embodiment of the present application provides an analog buzzer circuit, including:

the input end is connected with the output end of the controller and used for receiving the square wave with fixed frequency output by the controller; the value of the fixed frequency corresponds to the frequency value of the buzzer to be simulated; and one end of the signal processing circuit is connected with the input end, and the other end of the signal processing circuit is connected with the loudspeaker and is used for enhancing the square wave with the fixed frequency and then inputting the enhanced square wave into the loudspeaker so as to drive the loudspeaker to make the sound with the fixed frequency value.

In the embodiment of the application, the loudspeaker is driven to emit the sound with the fixed frequency value, the fixed frequency value corresponds to the frequency value of the buzzer to be simulated, the sound emitted by the loudspeaker can simulate the sound of the buzzer, and the sound production effect of the traditional buzzer is achieved. Compared with the traditional buzzer, the circuit of the analog buzzer is simple, the simple circuit is used for simulating the buzzer to sound, the active buzzer and the passive buzzer can be replaced, and the problem that a small number of sounding frequencies of the buzzer have deviation (namely, the quality is uneven) is solved; on the other hand, the circuit is simple, and the structural space is not limited, so that the applicability of the analog buzzer circuit is improved.

As a possible implementation manner, the signal processing circuit includes a triode, a first resistor, a second resistor and a protection circuit; one end of the first resistor is connected with the input end, and the other end of the first resistor is connected with the base electrode of the triode; one end of the second resistor is connected with the base electrode of the triode, and the other end of the second resistor is connected with the bias voltage and the emitting electrode of the triode; and the collector of the triode is connected with one end of the protection circuit, and the other end of the protection circuit is connected with the loudspeaker.

In the embodiment of the application, the signal processing circuit is used for enhancing the square wave with fixed frequency and then inputting the square wave into the loudspeaker, after the square wave is input into the base of the triode, the bias voltage is chopped into the square wave with the same frequency as the square wave through the characteristics of high level cut-off and low level conduction of the triode, and then the square wave is output to the loudspeaker through the protection circuit, so that the driving capability of the square wave is enhanced, the loudspeaker can normally sound, and the effect of simulating a buzzer is further achieved. The circuit has the advantages of simple structure, low cost of the triode, low cost, convenience in layout and strong applicability, and does not belong to a large device.

As a possible implementation manner, the protection circuit includes a diode, an anode of the diode is connected to a collector of the triode, a cathode of the diode is connected to the horn, and the diode is used for protecting the triode.

In this application embodiment, loudspeaker except being used for simulating the buzzer sound production, probably have other effects, in order to avoid the influence of other drive circuit to the triode, utilize the forward characteristic of conducting of diode, prevent that peripheral high voltage from anti-stringing from damaging the triode, improved the stability of whole circuit.

As a possible implementation, the protection circuit further includes a variable resistor; one end of the variable resistor is connected with the cathode of the diode, and the other end of the variable resistor is connected with the loudspeaker; the variable resistor is used for adjusting the current input to the horn.

In the embodiment of the application, the current input to the loudspeaker is adjusted through the variable resistor, so that the current can be prevented from being too large on one hand, and the volume of the loudspeaker can be adjusted through adjusting the current on the other hand.

As a possible implementation manner, the analog buzzer circuit further includes a capacitor, one end of the capacitor is connected to the input end, the other end of the capacitor is connected to one end of the first resistor, and the capacitor is used for blocking direct current and alternating current.

In the embodiment of the application, direct current in signals output by the controller can be filtered through the capacitor, only alternating current is conducted, and the influence of the direct current on horn driving is avoided.

As a possible implementation manner, the signal processing circuit includes a power amplifier, an input end of the power amplifier is connected to the input end, and an output end of the power amplifier is connected to the speaker.

In the embodiment of the application, the signal processing circuit is a power amplifier, and the power amplifier can stably complete the driving of the loudspeaker, so that the stability of the circuit is improved.

As a possible implementation mode, the controller is an ARM or a single chip microcomputer, and the output end is an I/O port of the ARM or the single chip microcomputer.

In the embodiment of the application, the controller can be an ARM or a single chip microcomputer, and is low in price and low in cost.

As a possible implementation, the fixed frequency is between 3-4 KHZ.

In the embodiment of the application, the buzzer frequency is in a range of 3-4KHZ, and the sound with the frequency of 3-4KHZ can better simulate the sound of the buzzer.

In a second aspect, an embodiment of the present application provides an electronic device, including: an apparatus body; a horn disposed on the apparatus body; a controller disposed within the device body, and an analog buzzer circuit as described in the first aspect and any one of the possible implementations of the first aspect.

As a possible implementation manner, the electronic device is a building interphone.

In this application embodiment, loudspeaker can be the loudspeaker on the electronic equipment, for the sound production of simulation buzzer, directly with simulation buzzer circuit with loudspeaker be connected can, when can not influence original circuit, realized the simulation of buzzer, improved the stability of electronic equipment operation, and reduced electronic equipment's cost.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

Fig. 1 is a schematic diagram of a first embodiment of an analog buzzer circuit provided in an embodiment of the present application;

fig. 2 is a schematic diagram of a second embodiment of an analog buzzer circuit provided in the embodiments of the present application;

fig. 3 is a schematic diagram of a third embodiment of an analog buzzer circuit provided in the embodiments of the present application;

fig. 4 is a schematic diagram of a fourth embodiment of an analog buzzer circuit provided in the embodiments of the present application.

Icon: 10-simulating a buzzer circuit; 11-an input terminal; 12-a signal processing circuit; 120-protection circuit.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

In the description of the present application, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the application usually place when using, and are only used for convenience in describing the present application and simplifying the description, but do not indicate or imply that the devices or elements that are referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

It should also be noted that, unless expressly stated or limited otherwise, the terms "disposed" and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

The simulated buzzer circuit provided by the embodiment of the application is used for simulating the sounding of the buzzer, the application of the buzzer is very wide, if the electronic equipment is in the process of man-machine interaction, every time the key is pressed, the key can correspondingly send a sound to feed back to the ear of a person to inform the person to be effective, and the simulated buzzer circuit can replace the original buzzer used for sounding.

Based on the application scenario, the embodiment of the present application first introduces the sound production (driving) principle of a loudspeaker (speaker).

A loudspeaker (loudspeaker) is a transducer that converts electrical signals into acoustic signals, and audio power vibrates a cone or diaphragm thereof through electromagnetic, piezoelectric or electrostatic effects and resonates (resonates) with the surrounding air to produce sound. When a drive signal with a fixed frequency is input, vibration sounds through an electric energy conversion effect of the horn, such as an electromagnetic effect, and the oscillation frequency of the vibration sounds is equal to the fixed frequency of the input drive signal. If the frequency of the input driving signal is changed, correspondingly, the oscillation frequency of the loudspeaker is changed, and the loudspeaker can be driven to emit high and low tones. In the embodiment of the application, the loudspeaker is driven to sound to simulate the buzzer to sound, and the buzzer generally does not need high or low sound, so that a driving signal with fixed frequency can be input.

The following describes an analog buzzer circuit according to an embodiment of the present application, based on the principle of sound production (driving) of a horn (speaker).

Referring to fig. 1, fig. 1 is a schematic diagram of an analog buzzer circuit 10 according to an embodiment of the present disclosure, as shown in fig. 1, the analog buzzer circuit 10 includes an input end 11 and a signal processing circuit 12, the input end 11 is connected to an output end of a controller, one end of the signal processing circuit 12 is connected to the input end 11, and the other end is connected to a speaker. The input end 11 is used for receiving a square wave with fixed frequency output by the controller; the value of the fixed frequency corresponds to the frequency value of the buzzer to be simulated; the signal processing circuit 12 is configured to enhance the square wave with a fixed frequency and input the enhanced square wave to the speaker, so as to drive the speaker to emit a sound with a fixed frequency value.

As can be seen from fig. 1 and the sounding principle of the speaker, when the input terminal 11 receives the square wave of the fixed frequency output by the controller, the square wave is enhanced by the signal processing circuit 12 and then input to the speaker, and according to the sounding principle of the speaker, the oscillation frequency of the speaker is equal to the fixed frequency value, and the sounded sound frequency is the fixed frequency, thereby playing the effect of simulating the sounding of the buzzer.

It is noted that the value of the fixed frequency corresponds to the frequency value of the buzzer to be simulated, which means that the value of the fixed frequency is equal to or close to the frequency value of the buzzer to be simulated, in practical cases, due to the error of the element parameters, absolute equality will not generally be achieved, but substantial closeness is achievable. The enhancement of the signal processing circuit 12 is to enhance the driving capability of the square wave, that is, the frequency, level, etc. of the square wave output by the signal processing circuit 12 are the same as those of the square wave output by the controller, and only current amplification is performed. The square wave output by the controller is enhanced because the square wave output by the controller alone is possibly unstable and has poor driving capability, and if the square wave is directly input to a loudspeaker, the loudspeaker cannot sound normally.

Of course, in practical application, a person skilled in the art can select a driving signal having the same function as a square wave according to actual requirements to realize the driving sound production of the horn.

Furthermore, the controller and the loudspeaker can be directly multiplexed with the original controller and loudspeaker on the electronic equipment, namely, the controller is the controller in the electronic equipment, and the loudspeaker is also the loudspeaker on the electronic equipment. The controller may be, for example, an ARM or a single chip, and the Output end of the controller is an Input/Output (I/O) port of the ARM or the single chip. With respect to how the controller controls the output end to output the square wave with fixed frequency, it can be understood that the I/O port can be used for outputting voltage, and when the I/O port outputs voltage, the controller can control the output voltage to be high level or low level, so that the square wave with fixed frequency can be generated by controlling the output of the I/O port to periodically change between high level and low level. The fixed frequency of the square wave is related to the period of the square wave signal, and assuming that the period T of the square wave signal is 1ms, the frequency F is 1/T1/0.001 is 1KHZ, and the period of the square wave refers to a period from one rising edge to the next rising edge, starting from the rising edge or the falling edge, where the starting position is calculated.

For a fixed frequency, the frequency of the buzzer corresponds to, and the general buzzer frequency is generally between 3-4KHZ, so the natural frequency can also be between 3-4KHZ, for example, the frequency value of 3.5KHZ, 3.6KHZ, 3.7KHZ, etc. Correspondingly, the period of the square wave can be calculated by T being 1/F, i.e. the reciprocal of the fixed frequency.

From the analysis, it can be seen that the loudspeaker is driven to emit the sound with the fixed frequency value, the fixed frequency value corresponds to the frequency value of the buzzer to be simulated, the sound emitted by the loudspeaker can simulate the sound of the buzzer, and the sound production effect of the traditional buzzer is achieved. Compared with the traditional buzzer, the circuit of the analog buzzer is simple, the simple circuit is used for simulating the buzzer to sound, the active buzzer and the passive buzzer can be replaced, and the problem that a small number of sounding frequencies of the buzzer have deviation (namely, the quality is uneven) is solved; on the other hand, since the circuit is simple and is not limited in structural space, the applicability of the analog buzzer circuit 10 is improved.

Two alternative embodiments are provided for signal processing circuit 12, which are described below.

Referring to fig. 2, for a first implementation of the signal processing circuit 12 according to the embodiment of the present disclosure, as shown in fig. 2, the signal processing circuit 12 includes a transistor Q, a first resistor R1, a second resistor R2, and a protection circuit 120. One end of the first resistor R1 is connected with the input end 11, and the other end of the first resistor R1 is connected with the base electrode of the triode Q; one end of the second resistor R2 is connected with the base electrode of the triode Q, and the other end of the second resistor R2 is connected with the bias voltage V and the emitting electrode of the triode Q; the collector of the triode Q is connected to one end of the protection circuit 120, and the other end of the protection circuit 120 is connected to the speaker.

Signal enhancement principle of the signal processing circuit 12: after the square wave is input to the base of the triode Q, the triode Q is turned on and off according to the high and low levels output by the I/O by the characteristics of the high level cut-off and the low level turn-on of the triode Q, the bias voltage V is chopped into a square wave with the same frequency as the square wave, and the square wave is output to the horn through the protection circuit 120, so that the driving capability of the square wave is enhanced. The bias voltage V has a voltage level equal to the high level of the square wave of the I/O output, and may be 3.3V, for example.

Further, the protection circuit 120 may include a diode D, wherein an anode of the diode D is connected to a collector of the transistor Q, a cathode of the diode D is connected to the speaker, and the diode D is used for protecting the transistor Q.

The principle that the diode D protects the triode Q: when the analog buzzer circuit 10 is used, because the horn belongs to an electronic device, other functions or functions may be provided, and other driving circuits are correspondingly provided, so that in order to avoid the influence of other driving circuits on the triode Q, the characteristic of forward conduction of the diode D is utilized, even if high voltage exists on the periphery, the triode Q cannot be conducted, and the peripheral high voltage cannot be reversely connected to the triode Q to damage the triode Q. By utilizing this characteristic of the diode D, the stability of the entire circuit can be improved.

Further, in addition to the diode D, the protection circuit 120 may further include a variable resistor R3, one end of the variable resistor R3 is connected to the cathode of the diode D, and the other end of the variable resistor R3 is connected to the speaker; the variable resistor R3 is used to regulate the current input to the horn.

Working principle of the variable resistor R3: the resistance of the variable resistor R3 is adjustable, is connected to the front end of the loudspeaker, and can adjust the current input to the loudspeaker, so that the current of the whole circuit can be avoided from being too large, and the current can be adjusted to adjust the volume of the loudspeaker.

In practical application, the variable resistor R3 can be adjusted to a suitable value through pre-debugging, so as to ensure the stability of the analog buzzer circuit 10, and the embodiment of the present application provides an optional resistance value: 49.9 ohms (error range 1%).

In the first embodiment of the signal processing circuit 12, the analog buzzer circuit 10 may further include a capacitor C, one end of the capacitor C is connected to the input terminal 11, the other end of the capacitor C is connected to one end of the first resistor R1, and the capacitor C is used for blocking direct current and alternating current. The characteristic that the blocking current of the capacitor C is alternating current is utilized to filter the direct current in the square wave signal, and only alternating current is conducted to avoid the influence of the direct current.

With reference to fig. 3, referring to the first embodiment of the signal processing circuit 12, a possible circuit structure of the analog buzzer circuit 10 according to the embodiment of the present disclosure is shown in fig. 3, where the input terminal 11 is connected to a capacitor C from an I/O port of a controller, the capacitor C is connected to a first resistor R1, the first resistor R1 is connected to a base of a transistor Q, one end of a second resistor R2 is connected to the base of the transistor Q, the other end of the second resistor R2 is connected to an emitter of the transistor Q, the emitter of the transistor Q is connected to a bias voltage, a collector of the transistor Q is connected to a diode D, the diode D is connected to a variable resistor R3, the variable resistor R3 is connected to one end of a horn, and the other end of.

The signal enhancement is realized through the triode Q, the circuit structure is simple, the triode Q is low in price and cost, the triode Q does not belong to a large device, the layout is convenient, and the applicability is strong.

Second embodiment of the signal processing circuit 12: the signal processing circuit 12 comprises a power amplifier, the input of which is connected to the input 11 and the output of which is connected to the loudspeaker.

The power amplifier is widely used for driving sound of various broadcast control devices, and the power amplifier is internally provided with a corresponding circuit and has the working principle that the power of a power supply is converted into current which changes according to an input signal by using the current control action of a triode or the voltage control action of a field effect tube, because the sound is waves with different amplitudes and different frequencies, namely alternating current signal current, the collector current of the triode is β times of the base current forever, β is the alternating current amplification factor of the triode, and by applying the point, if a small signal is injected into the base, the current flowing through the collector is equal to β times of the base current, and then the signal is isolated by a DC blocking capacitor, so that a large signal with the current (or voltage) β times of the original current is obtained, and the phenomenon becomes the amplification action of the triode, and the power amplification is finished after the continuous current amplification action.

When a power amplifier is used, a direct-current-blocking and alternating-current-blocking capacitor C may also be arranged at the front end of the power amplifier to play a role of blocking direct current and alternating current, referring to fig. 4 based on the second embodiment, for another possible circuit structure of the analog buzzer circuit 10 provided in the embodiment of the present application, as shown in fig. 4, an input end 11 is connected to the capacitor C, the capacitor C is connected to the power amplifier, the power amplifier is connected to one end of a horn, and the other end of the horn is grounded.

The power amplifier essentially utilizes the triode to amplify current, but the power amplifier is a device integrated with various circuits, can be directly connected into the circuit for use, can stably complete the driving of the loudspeaker, and improves the stability of the circuit.

In practical applications, the first embodiment and the second embodiment of the signal processing circuit 12 may be selected according to specific situations, and if the fund is sufficient and the cost is sufficient, the power amplifier (i.e. the second embodiment) may be directly adopted; assuming that the capital is not too abundant and the cost is limited, the circuit can be built by itself (i.e. the first embodiment). Except for the cost reason, the required structural space can be considered, the structural space occupied by the power amplifier is large, if the structural space is large, the form of the power amplifier can be adopted, and if the structural space is small, the first implementation mode is adopted.

Based on the same concept, an embodiment of the present application further provides an electronic device, including: an apparatus body; a horn disposed on the apparatus body; a controller disposed within the device body and an analog buzzer circuit 10.

When the electronic equipment is used, the simulation buzzer circuit 10 is directly connected with the output ends of the loudspeaker and the controller, the original circuit is not influenced, meanwhile, the replacement of the buzzer is realized, the running stability of the electronic equipment is improved, and the cost of the electronic equipment is reduced.

Furthermore, the electronic equipment can be a building interphone, and the building interphone is a gating and talkback control device installed at an entrance of a building security door. When the analog buzzer circuit 10 is applied to a building interphone, after a user presses a relevant key on the interphone, the analog buzzer circuit 10 simulates a buzzer to sound and sends out corresponding key sound.

The electronic device may be various devices having a key sounding function other than the building interphone, and the sounding of the key may be realized by the analog buzzer circuit 10, which is not limited herein.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An analog buzzer circuit, comprising:

the input end is connected with the output end of the controller and used for receiving the square wave with fixed frequency output by the controller; the value of the fixed frequency corresponds to the frequency value of the buzzer to be simulated;

and one end of the signal processing circuit is connected with the input end, the other end of the signal processing circuit is connected with the loudspeaker, and the signal processing circuit is used for enhancing the square wave of the fixed frequency and then inputting the square wave of the fixed frequency into the loudspeaker so as to drive the loudspeaker to make the sound of the value of the fixed frequency.

2. The circuit of claim 1, wherein the signal processing circuit comprises a transistor, a first resistor, a second resistor, and a protection circuit;

one end of the first resistor is connected with the input end, and the other end of the first resistor is connected with the base electrode of the triode; one end of the second resistor is connected with the base electrode of the triode, and the other end of the second resistor is connected with the bias voltage and the emitting electrode of the triode;

and the collector of the triode is connected with one end of the protection circuit, and the other end of the protection circuit is connected with the loudspeaker.

3. The circuit of claim 2, wherein the protection circuit comprises a diode, an anode of the diode is connected to a collector of the transistor, a cathode of the diode is connected to the horn, and the diode is used for protecting the transistor.

4. The circuit of claim 3, wherein the protection circuit further comprises a variable resistor; one end of the variable resistor is connected with the cathode of the diode, and the other end of the variable resistor is connected with the loudspeaker; the variable resistor is used for adjusting the current input to the horn.

5. The circuit of claim 2, wherein the analog buzzer circuit further comprises a capacitor, one end of the capacitor is connected to the input terminal, the other end of the capacitor is connected to one end of the first resistor, and the capacitor is used for blocking direct current and alternating current.

6. The circuit of claim 1, wherein the signal processing circuit comprises a power amplifier, an input of the power amplifier is connected to the input, and an output of the power amplifier is connected to the horn.

7. The circuit of any one of claims 1-6, wherein the controller is an ARM or a single chip microcomputer, and the output is an I/O port of the ARM or the single chip microcomputer.

8. The circuit according to any of claims 1-6, wherein the fixed frequency is between 3-4 KHZ.

9. An electronic device, comprising:

an apparatus body; a horn disposed on the apparatus body; a controller disposed within the device body and an analog buzzer circuit as claimed in any one of claims 1 to 8.

10. The electronic device of claim 9, wherein the electronic device is a building interphone.