CN204791944U - Passive magneto -electric buzzer drive circuit of volume adjustable - Google Patents

Abstract

The utility model relates to a passive magnetoelectric buzzer drive circuit with adjustable volume, which comprises: an input unit, a trigger unit, an input/output control unit, a reference buzzer drive unit and a buzzer volume adjustment module The input circuit is connected to the trigger circuit and the input/output control circuit respectively; the input/output control circuit is connected to the reference buzzer drive circuit and the buzzer volume adjustment unit respectively; the buzzer volume adjustment unit is connected to the reference buzzer drive unit And the buzzer is connected. The utility model proposes a passive magnetoelectric buzzer drive circuit with adjustable volume, which effectively solves the different demands on the volume of the buzzer in different environments.

Description

A passive magnetoelectric buzzer drive circuit with adjustable volume

technical field

The utility model relates to the driving technology of generating devices in the financial POS system, in particular to a passive magnetoelectric buzzer driving circuit with adjustable volume.

Background technique

The passive magnetoelectric buzzer has the advantage of low cost. It is a sounding device widely used in financial POS systems and electronic products. It is used to generate various prompts, and is widely used in fault alarms, operation feedback, and button volume output. . However, due to the variety of product application environments, some environments are relatively noisy, such as large shopping malls and supermarkets, and some environments are relatively quiet, such as convenience stores and western restaurants. This adopts a fixed volume and cannot meet various environmental needs, and the existing technology The realization of multi-level volume control depends on relatively complex software control, which is costly, difficult to operate, and not easy to integrate into the financial POS system. Therefore, it is urgent to solve the different requirements for the volume of the buzzer in different environments.

Contents of the invention

The purpose of the utility model is to provide a passive magnetoelectric buzzer drive circuit with adjustable volume to overcome the defects in the prior art; the utility model has a simple structure and is easy to realize.

In order to achieve the above object, the technical solution of the present invention is: a passive magnetoelectric buzzer drive circuit with adjustable volume, which is characterized in that it includes: an input circuit, a trigger circuit, and an input/output control circuit , a reference buzzer drive circuit and a buzzer volume adjustment unit; the input circuit is connected to the trigger circuit and the input/output control circuit respectively; the input/output control circuit is connected to the reference buzzer The buzzer drive circuit is connected with the buzzer volume adjustment unit; the buzzer volume adjustment unit is connected with the reference buzzer drive unit and the buzzer.

In an embodiment of the present invention, the input/output control circuit includes an MCU; the MCU includes several IO ports and several PWM ports.

In an embodiment of the present invention, the reference buzzer driving circuit includes a first resistor, a second resistor, a buzzer driving transistor and a power supply decoupling capacitor; one end of the first resistor is connected to the The PWM end of the input/output control circuit is connected, and the other end is connected with the base of the buzzer driving transistor; the emitter of the buzzer driving transistor is grounded through the second resistor; the buzzer driving The collector of the triode is connected to one end of the buzzer; one end of the power supply decoupling capacitor is grounded, and the other end is connected to the other end of the buzzer and connected to a high level.

In an embodiment of the present invention, the buzzer volume adjustment unit includes N volume adjustment circuits, and the volume adjustment circuits are respectively connected to the reference buzzer drive circuit and the input/output control circuit, Wherein, N is a positive integer greater than 1.

In an embodiment of the present invention, the volume adjustment circuit includes a third resistor, a fourth resistor, and a volume adjustment transistor; one end of the third resistor is connected to an IO end of the input/output control circuit , the other end is connected to the base of the volume adjusting transistor; the emitter of the volume adjusting transistor is grounded; the collector of the volume adjusting transistor is connected to the emitter of the buzzer driving transistor through the fourth resistor .

In an embodiment of the present invention, the trigger circuit includes a trigger button; two ends of the trigger button are respectively connected to another IO terminal and another IO terminal of the input/output control unit.

In an embodiment of the present invention, the input circuit includes several input button circuits and a display screen.

Compared with the prior art, the utility model has the following beneficial effects: the utility model proposes a volume-adjustable passive magnetoelectric buzzer drive circuit, by setting a multi-stage volume adjustment unit, combined with the existing The software and control method, the user can adjust the output volume level of the input button through the input circuit according to the noise level of the financial POS system application environment embedded in the circuit, and the reference buzzer drive circuit combines the control volume adjustment unit to drive the buzzer The corresponding sound volume of the buzzer effectively solves the different needs of the financial POS system for the volume of the buzzer in different environments.

Description of drawings

Fig. 1 is a circuit schematic diagram of a passive magnetoelectric buzzer drive circuit with adjustable volume in the utility model.

Fig. 2 is a schematic circuit diagram of another volume-adjustable passive magnetoelectric buzzer drive circuit of the present invention.

Fig. 3 is a circuit connection schematic diagram of another volume-adjustable passive magnetoelectric buzzer driving circuit in the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the technical solution of the utility model is described in detail.

The utility model provides a passive magnetoelectric buzzer drive circuit with adjustable volume, as shown in Figure 1, comprising: an input circuit, a trigger circuit, an input/output control circuit, and a reference buzzer drive circuit circuit and a buzzer volume adjustment unit; the input circuit is respectively connected with the trigger circuit and the input/output control circuit; the input/output control circuit is respectively connected with the reference buzzer drive circuit and the The buzzer volume adjustment unit is connected; the buzzer volume adjustment unit is connected to the reference buzzer drive circuit and the buzzer; the trigger circuit receives the first input signal sent by the input circuit to generate a trigger signal and sent to the input/output control circuit.

Further, in this embodiment, as shown in Figure 3, the input/output control circuit includes an MCU, which is an embedded controller of the financial POS system; the MCU includes several IO ports and several PWM ports; PIO1, PIO2 to PIO(n+1) are the input and output ports of the MCU, which can control the output or input high and low levels. PIO1 and PIO2 are used to trigger the key K1 drive, and the other PIOs are used for volume control. The PWM terminal is the pulse width of the MCU. The modulation signal output port can set the frequency and duty cycle of the PWM signal through the MCU.

Further, in this embodiment, as shown in FIG. 3 , the reference buzzer driving circuit includes a first resistor Rb1, a second resistor Re1, a buzzer driving transistor Q1 and a power supply decoupling capacitor C1 One end of the first resistor Rb1 is connected to the PWM end of the input/output control unit, that is, it is connected to the PWM output end of the MCU, and the other end is connected to the base of the buzzer driving transistor Q1; The emitter of the buzzer driving transistor Q1 is grounded through the second resistor Re1; the collector of the buzzer driving transistor Q1 is connected to one end of the buzzer LS1; one end of the power supply decoupling capacitor C1 is grounded, The other end is connected with the other end of the buzzer LS1 and connected to a high level.

Further, in this embodiment, as shown in FIG. 2 , the buzzer volume adjustment unit includes N volume adjustment circuits, and the volume adjustment circuits are respectively connected to the reference buzzer drive circuit and the input The / output control circuit is connected, wherein, N is a positive integer greater than 1.

Further, in this embodiment, as shown in FIG. 3 , the volume adjustment circuit includes a third resistor, a fourth resistor, and a volume adjustment transistor; one end of the third resistor is connected to the input/output control One IO terminal of the unit is connected, and the other end is connected with the base of the volume adjustment transistor; the emitter of the volume adjustment transistor is grounded; the collector of the volume adjustment transistor is connected to the buzzer via the fourth resistor The device drives the emitter of the transistor. In this embodiment, one end of Rb2 in the first volume adjustment circuit is connected to the PIO3 end of the MCU, and the other end is connected to the base of the first volume adjustment transistor Q2; the emitter of the first volume adjustment transistor Q2 is grounded; the first volume Adjust the collector of the transistor Q2 through Re2 to connect the emitter of the buzzer to drive the transistor Q1; The base of the N-1 volume-adjusting transistor Qn; the emitter of the N-1 volume-adjusting transistor Qn is grounded; the collector of the N-1 volume-adjusting transistor Qn is connected to the buzzer to drive the emitter of the transistor Q1 through Ren; In this embodiment, Rb1, Rb2, Rb3 to Rbn are base current-limiting resistors corresponding to each transistor, and the selected resistance values can make each transistor enter a saturated conduction state; Re1≈2Re2≈4Re3...≈2 ^{(n -1)} Ren.

Further, in this embodiment, as shown in FIG. 3 , the trigger circuit includes a trigger button K1; As shown in Figure 3, they are respectively connected to the PIO1 and PIO2 terminals of the MCU.

Further, in this embodiment, the input circuit includes several input key circuits and a display screen, which are used for key input and display of the financial POS system.

In order for those skilled in the art to further understand the volume-adjustable passive magnetoelectric buzzer driving circuit proposed by the present invention, further description will be made below in conjunction with the driving method of the circuit. It should be pointed out that the existing software and control methods involved in the description process are not the object of protection of the utility model, and the utility model only protects the structure of the circuit and its connection relationship.

The trigger circuit receives the first input signal sent by the input circuit, generates a trigger signal and sends it to the input/output control circuit; the input/output control circuit receives the trigger signal, generates a time width of Ts, and takes The PWM signal with a duty ratio of M:L is sent to the reference buzzer drive circuit through the PWM terminal to drive the buzzer to output sound; the input/output control circuit receives the second signal sent by the input circuit. The input signal generates N-1 IO signals, and correspondingly transmits to the volume adjustment circuit in the volume adjustment unit through each IO terminal; the reference buzzer drive circuit receives the volume adjustment signal of each volume adjustment unit circuit, Adjusting the sound volume output of the buzzer; wherein, M and L are both positive integers greater than or equal to 1. In this embodiment, the PWM outputs a square wave with a time width of 100 ms and a frequency of buzzer resonant frequency with a duty ratio of 1:1.

Further, in this embodiment, the connection terminals between the input/output control unit and the N-1 volume adjustment circuits are respectively the first IO terminal to the N-1th IO terminal; if the first IO terminal outputs a high level, The second to N-1IO terminals all output low levels, and the sound output of the buzzer is the first-level volume; if the second IO terminal outputs high levels, the first IO terminal and the third to N-1IO terminals Both terminals output low level, and the sound output of the buzzer is the second-level volume; and so on, if the N-1IO terminal outputs high level, the first to N-2IO terminals all output low level, The sound output of the buzzer is Nth level volume.

Further, in this embodiment, the user can preset each input button circuit in the input unit according to specific requirements, that is, set N-1 IO signal outputs corresponding to each input button circuit, so that each input The button circuit matches a buzzer sound volume output; when inputting through each input button circuit, the first input signal sent by the input button circuit is received in the trigger unit, the trigger button is closed, and a trigger signal is generated; The input/output control unit receives the trigger signal, generates a PWM signal, and drives the buzzer to output sound; at the same time, the input/output control unit receives the second input signal sent by the input button circuit, and generates a corresponding N -1 IO signal, which should be transmitted to the volume adjustment unit in the volume adjustment module through each IO terminal; the reference buzzer drive unit receives the volume adjustment signal output by each volume adjustment unit, and outputs the input button The circuit matches the volume of the buzzer sound.

The above are the preferred embodiments of the utility model, and all changes made according to the technical solution of the utility model, when the functional effect produced does not exceed the scope of the technical solution of the utility model, all belong to the protection scope of the utility model.

Claims (7)

1. A passive magnetoelectric buzzer drive circuit with adjustable volume, comprising: an input circuit, a trigger circuit, an input/output control circuit, a reference buzzer drive circuit and a buzzer buzzer volume adjustment unit; the input circuit is connected to the trigger circuit and the input/output control circuit; the input/output control circuit is connected to the reference buzzer drive circuit and the buzzer volume The adjusting unit is connected; the buzzer volume adjusting unit is connected with the reference buzzer driving unit and the buzzer. 2. The passive magnetoelectric buzzer driving circuit with adjustable volume according to claim 1, wherein the input/output control circuit includes an MCU; the MCU includes several IO ports and several PWM port. 3. The passive magnetoelectric buzzer driving circuit with adjustable volume according to claim 1, wherein the reference buzzer driving circuit comprises a first resistor, a second resistor, a The buzzer drives the triode and a power supply decoupling capacitor; one end of the first resistor is connected to the PWM terminal of the input/output control circuit, and the other end is connected to the base of the buzzer drive triode; the buzzer The emitter of the buzzer driving transistor is grounded through the second resistor; the collector of the buzzer driving transistor is connected to one end of the buzzer; one end of the power supply decoupling capacitor is grounded, and the other end is connected to the The other end of the buzzer is connected and connected to a high level. 4. A passive magnetoelectric buzzer drive circuit with adjustable volume according to claim 3, characterized in that, the buzzer volume adjustment unit comprises N volume adjustment circuits, and the volume adjustment The circuits are respectively connected with the reference buzzer drive circuit and the input/output control circuit, wherein, N is a positive integer greater than 1. 5. A passive magnetoelectric buzzer drive circuit with adjustable volume according to claim 4, wherein the volume adjustment circuit includes a third resistor, a fourth resistor and a volume adjustment transistor ; One end of the third resistor is connected to an IO end of the input/output control circuit, and the other end is connected to the base of the volume adjustment transistor; the emitter of the volume adjustment transistor is grounded; the volume adjustment transistor The collector of the buzzer is connected to the emitter of the buzzer driving triode through the fourth resistor. 6. The passive magnetoelectric buzzer driving circuit with adjustable volume according to claim 1, wherein the trigger circuit includes a trigger button; the two ends of the trigger button are respectively connected to the Another IO terminal of the input/output control unit is connected to another IO terminal. 7 . The passive magnetoelectric buzzer drive circuit with adjustable volume according to claim 1 , wherein the input circuit includes several input button circuits and a display screen.