Driving circuit, key and electronic equipment

Abstract

The invention relates to the technical field of electronic circuits, and discloses a driving circuit, a key and an electronic device, the driving circuit comprises a control module and a first constant current module; the control module is connected with the first constant current module, the first constant current module is further connected with the power supply and the piezoelectric ceramic, and the power supply is further connected with the power supply load; the power supply is used for supplying power to power supply load output power supply current and outputting charging current to the first constant current module; the control module is used for outputting a charging signal to the first constant current module; and the first constant current module is used for keeping the charging current constant according to the charging signal, and transmitting the constant charging current to the piezoelectric ceramic for charging so as to reduce the fluctuation of the power supply current. Compared with the prior art, when the piezoelectric ceramic is charged, the constant charging current is adopted, so that reduction of the current transmitted to the power supply load by the power supply is reduced, the power supply stability of the power supply is improved, and the influence on the work of other devices is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a driving circuit, a key, and an electronic device. Background Art

[0002] With the upgrade of various consumer electronic products and the improvement of user experience, the demand for vibration feedback function in product buttons is becoming more and more widespread. Currently, vibration feedback of button buttons can generally be achieved by driving piezoelectric ceramics with voltage. Specifically, the power supply transmits the output voltage to the boost circuit. The control module controls the boost circuit to output a sinusoidal voltage signal to charge and discharge the piezoelectric ceramic, thus achieving vibration feedback.

[0003] Existing power supplies connected to piezoelectric ceramics are typically connected in parallel with other power supply loads, such as light-emitting diodes (LEDs) for light feedback. However, due to the voltage-driven operation, the voltage across the piezoelectric ceramic is low at the beginning of the drive, while the slope of the voltage signal is relatively large (i.e., the slope at the beginning of the sine wave, which reflects the rate of change of voltage; a greater rate of change in voltage indicates a greater current). This results in a relatively large current being transmitted to the piezoelectric ceramic, which in turn reduces the current transmitted to other devices, causing unstable operation of these devices and, consequently, poor power supply stability, affecting the operation of other devices. Summary of the Invention

[0004] The main purpose of this application is to provide a driving circuit, a button and an electronic device, which aims to solve the existing technical problem that when piezoelectric ceramics are powered by a power supply, other devices connected to the power supply become unstable due to the use of voltage-type drive, resulting in poor stability of the power supply and affecting the operation of other devices.

[0005] To achieve the above object, the present application provides a driving circuit, which includes: a control module and a first constant current module;

[0006] The control module is connected to the first constant current module, the first constant current module is further connected to a power supply and a piezoelectric ceramic, and the power supply is further connected to a power supply load;

[0007] The power supply is configured to output a power supply current to the power supply load and output a charging current to the first constant current module;

[0008] The control module is configured to output a charging signal to the first constant current module;

[0009] The first constant current module is used to control the charging current according to the charging signal, and transmit the constant charging current to the piezoelectric ceramic for charging, so as to reduce the fluctuation of the power supply current.

[0010] In one embodiment, the driving circuit further includes: a second constant current module;

[0011] The second constant current module is connected to the ground terminal, the piezoelectric ceramic and the control module respectively;

[0012] The control module is further configured to output a discharge signal to the second constant current module;

[0013] The second constant current module is used to constant the discharge current output by the charged piezoelectric ceramic according to the discharge signal, and to output the constant discharge current to the ground terminal so as to enable the piezoelectric ceramic to perform vibration feedback.

[0014] In one embodiment, the control module is further configured to obtain preset vibration information of the piezoelectric ceramic;

[0015] The control module is further configured to obtain the ceramic capacitance value of the piezoelectric ceramic, the charging current value of the constant current charging current, and the discharging current value of the constant current discharging current;

[0016] The control module is further configured to generate a charging signal according to the preset vibration information, the ceramic capacitance value, and the charging current value, and to generate a discharging signal according to the preset vibration information, the ceramic capacitance value, and the discharging current value;

[0017] The control module is further configured to transmit the charging signal to the first constant current module and transmit the discharging signal to the second constant current module, so that the piezoelectric ceramic performs vibration feedback according to the preset vibration information.

[0018] In one embodiment, the preset vibration information includes: a preset vibration speed;

[0019] The control module is further configured to determine a corresponding preset charging slope and a preset discharging slope according to the preset vibration speed;

[0020] The control module is further configured to determine a charge duty cycle according to the preset charge slope, the ceramic capacitance value, and the charge current value, and to determine a discharge duty cycle according to the preset discharge slope, the ceramic capacitance value, and the discharge current value;

[0021] The control module is further configured to generate a charging signal according to the charging duty cycle, and generate a discharging signal according to the discharging duty cycle.

[0022] In one embodiment, the preset vibration information includes: a preset vibration amplitude;

[0023] The control module is further configured to determine a corresponding preset charging voltage and a preset discharging voltage according to the preset vibration amplitude;

[0024] The control module is further configured to determine a charging duty cycle and a charging duration according to the preset charging voltage, the ceramic capacitance value, and the charging current value, and to determine a discharge duty cycle and a discharge duration according to the preset discharge voltage, the ceramic capacitance value, and the discharge current value;

[0025] The control module is further configured to generate a charging signal according to the charging duty cycle and the charging duration, and to generate a discharging signal according to the discharging duty cycle and the discharging duration.

[0026] In one embodiment, the control module is further configured to output a first detection signal to the first constant current module according to a preset charging duration when the power is first turned on, so that the first constant current module charges the piezoelectric ceramic according to the first detection signal;

[0027] The control module is further configured to collect the port voltage of the piezoelectric ceramic after charging, and determine the ceramic capacitance value of the piezoelectric ceramic according to the charging current value, the port voltage, and the preset charging time.

[0028] In one embodiment, the control module is further configured to, after obtaining the ceramic capacitance value, output a second detection signal to the second constant current module according to a preset discharge duration, so that the second constant current module discharges the piezoelectric ceramic according to the second detection signal;

[0029] The preset charging time is T1, the preset discharging time is T2, the charging current value is I1, the discharging current value is I2, and T2>T1*I1 / I2.

[0030] In one embodiment, the driving circuit further includes: a first current limiting module and a second current limiting module;

[0031] The first current limiting module is connected to the control module and the first constant current module respectively, and the second current limiting module is connected to the control module and the second constant current module respectively;

[0032] The first current limiting module is configured to limit the current of the charging signal output by the control module and transmit the current-limited charging signal to the first constant current module;

[0033] The second current limiting module is used to limit the current of the discharge signal output by the control module and transmit the current-limited discharge signal to the second constant current module.

[0034] In addition, to achieve the above-mentioned purpose, the present application also provides a key, which includes piezoelectric ceramics and the driving circuit as described above.

[0035] In addition, to achieve the above-mentioned purpose, the present application also provides an electronic device, which includes the key as described above.

[0036] The present application provides a drive circuit, a button and an electronic device, wherein the drive circuit includes: a control module and a first constant current module; the control module is connected to the first constant current module, the first constant current module is also connected to a power supply and a piezoelectric ceramic, and the power supply is also connected to a power supply load; the power supply is used to output a supply current to the power supply load and output a charging current to the first constant current module; the control module is used to output a charging signal to the first constant current module; the first constant current module is used to constant the charging current according to the charging signal, and transmit the constant charging current to the piezoelectric ceramic for charging, so as to reduce the fluctuation of the supply current.

[0037] In this application, the driving circuit can output a charging signal to the first constant current module through the control module. The first constant current module can then constant the charging current provided by the power supply according to the charging signal, and then transmit the constant current charging current to the piezoelectric ceramic for charging. Compared to the existing voltage-based drive, the present application uses the constant current charging current when charging the piezoelectric ceramic, thereby reducing the current transmitted from the power supply to the power supply load, thereby improving the stability of the power supply and reducing the impact on the operation of other devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0039] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0040] Figure 1 This is a schematic structural diagram of the first embodiment of the driving circuit of the present application;

[0041] Figure 2 This is a circuit schematic diagram of the first embodiment of the driving circuit of this application.

[0042] Description of Figure Numbers:

[0043]

[0044] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0045] It should be understood that the specific embodiments described herein are merely used to explain the technical solutions of the present application and are not intended to limit the present application.

[0046] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0047] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0048] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0049] Understandably, with the upgrade of various consumer electronic products and the improvement of user experience, the demand for vibration feedback function in product buttons is becoming more and more widespread. Currently, vibration feedback of buttons can generally be achieved by driving the piezoelectric ceramic 4 with voltage. Specifically, the power supply 3 transmits the output voltage to the boost circuit. The control module 1 controls the boost circuit to output a sinusoidal voltage signal to the piezoelectric ceramic 4 for charging and discharging, thereby achieving vibration feedback.

[0050] The power supply 3 connected to the existing piezoelectric ceramic 4 is typically also connected in parallel with other power supply loads 5 to provide power, such as light-emitting diodes (LEDs) for light feedback. However, due to the voltage-driven operation, when the piezoelectric ceramic 4 is initially driven, the voltage value of the piezoelectric ceramic 4 is low, while the slope of the voltage signal is relatively large (i.e., the slope at the beginning of the sine wave, which reflects the rate of change of voltage; a greater rate of change of voltage indicates a greater current). This results in a relatively large current being transmitted to the piezoelectric ceramic 4, which in turn reduces the current transmitted by the power supply 3 to other devices, causing unstable operation of these devices. Consequently, the power supply stability of the power supply 3 is poor, affecting the operation of these other devices.

[0051] To address the above-mentioned drawbacks, this embodiment provides a drive circuit that may include a control module 1 and a first constant current module 2. The drive circuit may output a charging signal to the first constant current module 2 via the control module 1. The first constant current module 2 may regulate the charging current provided by the power supply 3 according to the charging signal, and then transmit the regulated charging current to the piezoelectric ceramic 4 for charging. Compared to the existing voltage-based drive, this embodiment uses the regulated charging current when charging the piezoelectric ceramic 4, thereby reducing the current transmitted from the power supply 3 to the power supply load 5, thereby improving the stability of the power supply 3 and reducing the impact on the operation of other devices.

[0052] For ease of understanding, the following Figures 1 to 2 The driving circuit provided in the embodiment of the present application is described in detail.

[0053] Reference Figure 1 , Figure 1 This is a structural diagram of the first embodiment of the driving circuit of the present application, as shown in FIG. Figure 1 As shown, in this embodiment, the driving circuit includes: a control module 1 and a first constant current module 2;

[0054] The control module 1 is connected to the first constant current module 2 , the first constant current module 2 is further connected to a power supply 3 and a piezoelectric ceramic 4 , and the power supply 3 is further connected to a power supply load 5 .

[0055] It should be noted that the control module 1 can be any module with data processing and program running functions, such as a microcontroller (MCU), etc., and this embodiment does not limit this.

[0056] It should also be noted that the first constant current module 2 can be a module that performs constant current operation on current, such as a voltage stabilizer, a switching power supply 3 chip, etc. Of course, it can also be other modules with constant current function, which is not limited in this embodiment.

[0057] It is understandable that in this embodiment, the first constant current module 2 can be connected to the control module 1 and the power supply 3 respectively, and the power supply 3 can be any power supply 3. At the same time, the power supply 3 in this embodiment can also be connected to other loads, and the other loads can be any load that requires electricity, for example, it can be a load used in conjunction with the piezoelectric ceramic 4 (such as a light-emitting diode, when the user presses the piezoelectric ceramic 4, the light-emitting diode emits light feedback), or it can be other loads that are not used in conjunction with the piezoelectric ceramic 4 but can share a power supply 3 with the piezoelectric ceramic 4. This embodiment does not impose any restrictions on this.

[0058] like Figure 1 As shown, in this embodiment, the first constant current module 2 can be connected to the positive electrode of the piezoelectric ceramic 4, and the negative electrode of the piezoelectric ceramic 4 can be connected to the ground terminal. In actual use, the power supply 3 is used to output the supply current to the power supply load 5 and output the charging current to the first constant current module 2;

[0059] The control module 1 is configured to output a charging signal to the first constant current module 2;

[0060] The first constant current module 2 is used to control the charging current according to the charging signal, and transmit the constant charging current to the piezoelectric ceramic 4 for charging, so as to reduce the fluctuation of the power supply current.

[0061] It should be understood that the above-mentioned power supply current may be a current for supplying power to the power supply load 5 .

[0062] The charging signal may be a signal for controlling the constant current operation of the first constant current module 2, and the charging current may be a current for charging the piezoelectric ceramic 4. In this embodiment, the piezoelectric ceramic 4 can induce vibration feedback through charging and discharging. Specifically, when the piezoelectric ceramic 4 is charged, charge accumulates within the ceramic, generating an electric field that causes the electric domains to shift and align, causing the ceramic lattice to distort, thereby causing deformation and initiation of vibration. When the piezoelectric ceramic 4 is discharged, the accumulated charge is released, the electric field weakens or disappears, the electric domains gradually return to their original disordered state, the lattice distortion also decreases or disappears, and the vibration gradually weakens until it stops.

[0063] Furthermore, when the piezoelectric ceramic 4 is driven by voltage, the slope of the sinusoidal voltage signal is relatively high at the beginning of the drive, resulting in a relatively large charging current for charging the piezoelectric ceramic 4. As a result, the current of the power supply load 5 connected to the same power supply 3 as the piezoelectric ceramic 4 is reduced, resulting in poor stability of the power supply 3.

[0064] In this embodiment, power supply 3 can provide power supply current to power supply load 5 and output charging current to first constant current module 2. When the user presses piezoelectric ceramic 4 and requires vibration feedback, control module 1 can output a charging signal to first constant current module 2. First constant current module 2 can then perform a constant current operation on the charging current provided by power supply 3 and transmit the constant current to piezoelectric ceramic 4 for charging. Since the constant current is used for charging, the current transmitted from power supply 3 to power supply load 5 is reduced, thereby improving the stability of power supply 3 and reducing the impact on the operation of other components.

[0065] Further, in order to make the piezoelectric ceramic 4 complete the vibration feedback, continue as follows Figure 1 As shown, in this embodiment, the driving circuit further includes: a second constant current module 6;

[0066] The second constant current module 6 is connected to the ground terminal, the piezoelectric ceramic 4 and the control module 1 respectively;

[0067] The control module 1 is further configured to output a discharge signal to the second constant current module 6;

[0068] The second constant current module 6 is used to constant the discharge current output by the charged piezoelectric ceramic 4 according to the discharge signal, and to output the constant discharge current to the ground terminal so as to enable the piezoelectric ceramic 4 to perform vibration feedback.

[0069] It should be noted that the second constant current module 6 can be a module that performs constant current operation on current, such as a voltage stabilizer, a switching power supply 3 chip, etc. Of course, it can also be other modules with constant current function, which is not limited in this embodiment.

[0070] It should also be noted that the discharge signal may be a module for controlling the second constant current module 6 to perform a discharge operation, and the discharge current may be a current generated by the piezoelectric ceramic 4 when the charge is released.

[0071] It is understandable that since the charging and discharging of the piezoelectric ceramic 4 can be completed through the same end, Figure 1 As shown, in this embodiment, the second constant current module 6 can be connected to the first constant current module 2, thereby achieving connection with the same end of the piezoelectric ceramic 4, and the other end of the second constant current module 6 can be connected to the ground end.

[0072] In actual use, after the piezoelectric ceramic 4 is charged, the piezoelectric ceramic 4 begins to release the charge and generate a discharge current. The control module 1 can output a discharge signal to the second constant current module 6. The second constant current module 6 can receive the discharge current and perform a constant current operation, and then export the constant current discharge current to the ground end, so that the piezoelectric ceramic 4 completes vibration feedback.

[0073] Furthermore, in order to achieve the constant current function, refer to Figure 2 , Figure 2 This is a circuit diagram of the first embodiment of the driving circuit of this application. Figure 2 As shown, in this embodiment, the first constant current module 2 includes: a first resistor R1, a first transistor Q1 and a second transistor Q2;

[0074] The first end of the first resistor R1 is connected to the power supply 3, the second end of the first resistor R1 is connected to the collector of the first transistor Q1, the base of the first transistor Q1 is connected to the control module 1 and the collector of the second transistor Q2, respectively, the emitter of the first transistor Q1 is connected to the base of the second transistor Q2 and the piezoelectric ceramic 4, respectively, and the emitter of the second transistor Q2 is grounded.

[0075] It should be understood that, in this embodiment, the first transistor Q1 and the second transistor Q2 may be NPN transistors.

[0076] It should be noted that the resistance of the first resistor R1 can be set according to the current required for constant current operation, and this embodiment does not limit this.

[0077] In actual use, when the control module 1 outputs a charging signal, the base of the first transistor Q1 receives the charging signal, the collector and emitter of the first transistor Q1 are turned on, and the collector of the first transistor Q1 receives the charging current output by the power supply 3 after passing through the first resistor R1. At this time, the base of the second transistor Q2 receives the current, and the collector and emitter of the second transistor Q2 are turned on. In this way, the first transistor Q1 and the second transistor Q2 clamp each other and maintain a balanced state, thereby completing the constant current operation of the charging current provided by the power supply 3, and transmitting the constant current charging current through the emitter of the first transistor Q1 to the piezoelectric ceramic 4 for charging.

[0078] Furthermore, in order to perform constant current operation on the discharge current, continue as follows Figure 2 As shown, in this embodiment, the second constant current module 6 includes: a second resistor R2, a third transistor Q3 and a fourth transistor Q4;

[0079] The collector of the third transistor Q3 is connected to the piezoelectric ceramic 4, the base of the third transistor Q3 is respectively connected to the collector of the fourth transistor Q4 and the control module 1, the emitter of the third transistor Q3 is respectively connected to the base of the fourth transistor Q4 and the first end of the second resistor R2, the emitter of the fourth transistor Q4 is grounded, and the second end of the second resistor R2 is connected to the ground end.

[0080] It is understandable that the resistance of the second resistor R2 can be set according to the current required for constant current operation, and this embodiment does not limit this.

[0081] In actual use, similarly, when the control module 1 outputs a discharge signal, the base of the third transistor Q3 receives the discharge signal, the collector and emitter of the third transistor Q3 are turned on, and the collector of the third transistor Q3 receives the discharge current released by the piezoelectric ceramic 4. At this time, the base of the fourth transistor Q4 receives the current, and the collector and emitter of the fourth transistor Q4 are turned on. In this way, the third transistor Q3 and the fourth transistor Q4 clamp each other and are positioned in a balanced state, thereby completing the constant current operation of the discharge current, and transmitting the constant current discharge current to the ground through the emitter of the third transistor Q3.

[0082] It should be emphasized that since this embodiment uses a transistor to achieve constant current, the charging signal and the discharging signal output by the control module 1 in this embodiment can both be pulse width modulation (PWM) signals. Furthermore, since charging and discharging are generally performed alternately, the charging signal and the discharging signal in this embodiment are complementary signals.

[0083] Furthermore, since the output of the charging signal and the discharging signal in this embodiment will increase suddenly, in order to protect the transistor, such as Figure 2 As shown, in this embodiment, the driving circuit further includes: a first current limiting module 7 and a second current limiting module 8;

[0084] The first current limiting module 7 is connected to the control module 1 and the first constant current module 2 respectively, and the second current limiting module 8 is connected to the control module 1 and the second constant current module 6 respectively;

[0085] The first current limiting module 7 is used to limit the current of the charging signal output by the control module 1 and transmit the charging signal after current limiting to the first constant current module 2;

[0086] The second current limiting module 8 is used to limit the current of the discharge signal output by the control module 1 and transmit the limited discharge signal to the second constant current module 6 .

[0087] It should be noted that the first current limiting module 7 and the second current limiting module 8 may be modules for current limiting, such as resistors.

[0088] like Figure 2 As shown, the first current limiting module 7 includes: a third resistor R3, and the second current limiting module 8 includes: a fourth resistor R4;

[0089] A first end of the third resistor R3 is connected to the control module 1, a second end of the third resistor R3 is connected to the base of the first transistor Q1, a first end of the fourth resistor R4 is connected to the control module 1, and a second end of the fourth resistor R4 is connected to the base of the third transistor Q3.

[0090] It is understandable that the resistance values ​​of the third resistor R3 and the fourth resistor R4 can be set according to actual conditions, and this embodiment does not limit this.

[0091] In actual use, when the control module 1 outputs a charging signal, the third resistor R3 can perform a current limiting operation on the charging signal, and transmit the charging signal after current limiting to the first transistor Q1, so that the collector and emitter of the first transistor Q1 are turned on; when the control module 1 outputs a discharge signal, the fourth resistor R4 can perform a current limiting operation on the discharge signal, and transmit the discharge signal after current limiting to the third transistor Q3, so that the collector and emitter of the third transistor Q3 are turned on.

[0092] Furthermore, in order to realize vibration feedback only when the user presses the piezoelectric ceramic 4, continue as follows Figure 2 As shown, in this embodiment, the driving circuit further includes: an acquisition module 8;

[0093] The acquisition module 8 is connected to the control module 1 and the piezoelectric ceramic 4 respectively;

[0094] The control module 1 is further configured to collect the piezoelectric current generated by the piezoelectric ceramic 4 through the collection module 8 when the piezoelectric ceramic 4 is pressed, and output the charging signal to the first constant current module 2 when the piezoelectric current reaches a preset current threshold.

[0095] It should be noted that the piezoelectric current can be the current generated when the piezoelectric ceramic 4 is pressed. The acquisition module 8 can be any module with a voltage acquisition function. Since the piezoelectric current generated by the piezoelectric ceramic 4 is an analog signal, the MCU can recognize it as a digital signal. Therefore, the acquisition module 8 can also have an analog-to-digital conversion function, such as an analog-to-digital converter.

[0096] It should also be noted that the above-mentioned preset current threshold can be a current threshold for determining whether the user presses the piezoelectric ceramic 4 , and can be set according to actual conditions, and this embodiment does not limit this.

[0097] It is understandable that, in this embodiment, the acquisition module 8 , the first constant current module 2 , and the second constant current module 6 may all be connected to the same end of the piezoelectric ceramic 4 .

[0098] In actual use, the acquisition module 8 can collect the piezoelectric current generated by the piezoelectric ceramic 4 and transmit it to the control module 1. The control module 1 can then compare the piezoelectric current with a preset current threshold. If the piezoelectric current does not reach the preset current threshold, it can indicate that the user is not pressing the piezoelectric ceramic 4, and the control module 1 will not output a charging signal or a discharging signal. If the piezoelectric current reaches the preset current threshold, it can indicate that the user is pressing the piezoelectric ceramic 4, and the control module 1 will alternately output a charging signal and a discharging signal to charge and discharge the piezoelectric ceramic 4.

[0099] In this embodiment, the drive circuit can output a charging signal to the first constant current module 2 via the control module 1. The first constant current module 2 can then regulate the charging current provided by the power supply 3 according to the charging signal and then transmit the regulated charging current to the piezoelectric ceramic 4 for charging. Compared to the existing voltage-based drive, since this embodiment uses the regulated charging current when charging the piezoelectric ceramic 4, the current transmitted from the power supply 3 to the power supply load 5 is reduced, thereby improving the stability of the power supply 3 and reducing the impact on the operation of other devices.

[0100] It should also be emphasized that since the traditional voltage-type driving method is generally implemented through an integrated circuit (IC), the hardware cost is relatively high. In this embodiment, only smaller devices (i.e., the above-mentioned resistors and transistors) can be used to achieve constant current driving of the piezoelectric ceramic 4, thereby reducing the hardware cost.

[0101] Continue based on Figure 1 and Figure 2 , and based on the above-mentioned first embodiment, a second embodiment of the driving circuit of this application is proposed.

[0102] In order to achieve personalized setting of the vibration of the piezoelectric ceramic 4, such as Figure 1 and Figure 2 As shown, in this embodiment, the control module 1 is further used to obtain preset vibration information of the piezoelectric ceramic 4 .

[0103] It should be noted that the preset vibration information may be information related to the vibration of the piezoelectric ceramic 4 , such as vibration speed, vibration amplitude, etc. The preset vibration information may be set by the user in advance according to vibration requirements and stored in the control module 1 .

[0104] The control module 1 is further configured to obtain the ceramic capacitance value of the piezoelectric ceramic 4, the charging current value of the constant current charging current, and the discharging current value of the constant current discharging current;

[0105] The control module 1 is further configured to generate a charging signal according to the preset vibration information, the ceramic capacitance value, and the charging current value, and to generate a discharge signal according to the preset vibration information, the ceramic capacitance value, and the discharge current value;

[0106] The control module 1 is further configured to transmit the charging signal to the first constant current module 2 and the discharging signal to the second constant current module 6 , so that the piezoelectric ceramic 4 performs vibration feedback according to the preset vibration information.

[0107] It is understandable that since the piezoelectric ceramic 4 can be equivalent to a capacitor, the above-mentioned ceramic capacitance value can be the capacitance value of the piezoelectric ceramic 4, which can be calculated based on the specific piezoelectric ceramic 4. The above-mentioned charging current value can be the current value of the charging current after constant current operation, which can be obtained based on the actual circuit design (for example, the voltage output by the above-mentioned power supply 3 and the resistance value of the first resistor R1). The above-mentioned discharge current value can be the current value of the discharge current after constant current operation, which can also be obtained based on the actual circuit design (for example, the voltage of the piezoelectric ceramic 4 and the resistance value of the second resistor R2).

[0108] In actual use, when it is necessary to set the vibration amplitude or vibration speed of the piezoelectric ceramic 4, the control module 1 in this embodiment can pre-acquire the vibration amplitude or vibration speed required as the above-mentioned preset vibration information, and calculate and generate a charging signal based on the preset vibration information, the ceramic capacitance value of the piezoelectric ceramic 4 and the charging current value of the constant current, and transmit it to the first constant current module 2; at the same time, according to the preset vibration information, the ceramic capacitance value of the piezoelectric ceramic 4 and the discharge current value of the discharge current after the constant current, calculate and generate a discharge signal and transmit it to the second constant current module 6. The first constant current module 2 can charge the piezoelectric ceramic 4 according to the charging signal, and the second constant current module 6 can discharge the piezoelectric ceramic 4 according to the discharge signal, so that the piezoelectric ceramic 4 can perform vibration feedback according to the corresponding vibration amplitude or vibration speed.

[0109] Furthermore, if the user wants to perform vibration feedback according to a certain vibration speed of the piezoelectric ceramic 4, then in this embodiment, the preset vibration information includes: a preset vibration speed;

[0110] The control module 1 is further configured to determine a corresponding preset charging slope and a preset discharging slope according to the preset vibration speed;

[0111] The control module 1 is further configured to determine a charge duty cycle according to the preset charge slope, the ceramic capacitance value, and the charge current value, and to determine a discharge duty cycle according to the preset discharge slope, the ceramic capacitance value, and the discharge current value;

[0112] The control module 1 is further configured to generate a charging signal according to the charging duty cycle, and generate a discharging signal according to the discharging duty cycle.

[0113] It should be noted that the different vibration speeds of the piezoelectric ceramic 4 during charging and discharging can be reflected as different slopes of the vibration waveform of the piezoelectric ceramic 4 . That is, the slope of the vibration waveform of the piezoelectric ceramic 4 during vibration can determine the vibration speed of the piezoelectric ceramic 4 . Therefore, in this embodiment, if the vibration speed of the piezoelectric ceramic 4 is to be achieved at a predetermined speed, the slope of the vibration waveform of the piezoelectric ceramic 4 can be achieved by achieving the corresponding predetermined slope.

[0114] Furthermore, in this embodiment, the preset charging slope may be the slope of the vibration waveform of the piezoelectric ceramic 4 at a preset vibration speed during charging, and the preset discharging slope may be the slope of the vibration waveform of the piezoelectric ceramic 4 at a preset vibration speed during discharging. In this embodiment, different preset vibration speeds may correspond to different preset charging slopes and preset discharging slopes.

[0115] In actual use, the control module 1 can determine the corresponding preset charging slope and preset discharging slope according to the preset vibration speed that the user needs to achieve. For the convenience of subsequent description, in this embodiment, the above-mentioned preset charging slope is recorded as XC, and the preset discharging slope is recorded as XF.

[0116] It is understandable that the above-mentioned charging duty cycle can be the duty cycle of the charging signal, and the above-mentioned discharging duty cycle can be the duty cycle of the discharging signal. Since both the charging signal and the discharging signal in this embodiment can be PWM signals, different vibration speeds can be adjusted by adjusting the duty cycle of the PWM signal.

[0117] The ceramic capacitor value can be denoted as C, the charging current value as I1, the discharging current value as I2, the charging duty cycle as PC, and the discharging duty cycle as PF. After the control module 1 obtains the preset charging slope XC and the preset discharging slope XF, the control module 1 can determine the charging duty cycle PC of the charging signal based on the preset charging slope XC, the ceramic capacitor value C, and the charging current value I1, specifically as XC = PC * I1 / C. Similarly, the control module 1 can determine the discharge duty cycle PF of the discharge signal based on the preset discharge slope XF, the ceramic capacitor value C, and the discharge current value I2, specifically as XF = PC * I2 / C.

[0118] After obtaining the charging duty cycle PC, the control module 1 can generate a corresponding charging signal according to the charging duty cycle and transmit it to the first constant current module 2. After obtaining the discharge duty cycle PF, the control module 1 can generate a corresponding discharge signal according to the discharge duty cycle and transmit it to the second constant current module 6. This allows the piezoelectric ceramic 4 to perform vibration feedback at a preset vibration speed.

[0119] It should be emphasized that when the capacitance value of the piezoelectric ceramic 4 is adjusted, the corresponding charging duty cycle PC and the corresponding discharging duty cycle PF can also be calculated in the above manner to generate corresponding charging signals and discharging signals, so that different piezoelectric ceramics 4 can all perform vibration feedback according to the above preset vibration speed.

[0120] Furthermore, if the user wants to perform vibration feedback according to a certain vibration amplitude of the piezoelectric ceramic 4, then in this embodiment, the preset vibration information includes: a preset vibration amplitude;

[0121] The control module 1 is further configured to determine a corresponding preset charging voltage and a preset discharging voltage according to the preset vibration amplitude;

[0122] The control module 1 is further configured to determine a charging duty cycle and a charging duration according to the preset charging voltage, the ceramic capacitance value, and the charging current value, and to determine a discharge duty cycle and a discharge duration according to the preset discharge voltage, the ceramic capacitance value, and the discharge current value;

[0123] The control module 1 is further configured to generate a charging signal according to the charging duty cycle and the charging duration, and to generate a discharging signal according to the discharging duty cycle and the discharging duration.

[0124] It should be noted that the different vibration amplitudes of the piezoelectric ceramic 4 during charging and discharging can be reflected as different voltages during charging and discharging. That is, the voltage level during charging and discharging determines the vibration amplitude of the piezoelectric ceramic 4. Therefore, in this embodiment, to achieve a predetermined vibration amplitude for the piezoelectric ceramic 4, the voltage during charging and discharging can be increased to the corresponding predetermined voltage.

[0125] Furthermore, in this embodiment, the preset charging voltage may be the voltage when charging the piezoelectric ceramic 4, and the preset discharging voltage may be the voltage when discharging the piezoelectric ceramic 4. Different preset vibration amplitudes in this embodiment may correspond to different preset charging voltages and preset discharging voltages.

[0126] In actual use, the control module 1 can determine the corresponding preset charging voltage and preset discharging voltage according to the preset vibration amplitude that the user needs to achieve. For the convenience of subsequent description, in this embodiment, the above-mentioned preset charging voltage is recorded as VC and the preset discharging voltage is recorded as VF.

[0127] It is understood that the aforementioned charging duration can be the duration of charging of the piezoelectric ceramic 4, or the duration of outputting the charging signal; the aforementioned discharging duration can be the duration of discharging of the piezoelectric ceramic 4, or the duration of outputting the discharge signal. For ease of subsequent description, in this embodiment, the charging duration is denoted as TC and the discharging duration is denoted as TF.

[0128] Furthermore, after the control module 1 obtains the preset charging voltage VC and the preset discharging voltage VF, the control module 1 can determine the charging duty cycle PC and the charging time TC of the charging signal according to the preset charging voltage VC, the ceramic capacitance value C and the charging current value I1, specifically VC=PC*I1*TC / C; similarly, the control module 1 can determine the discharge duty cycle PF and the discharge time TF of the discharge signal according to the preset discharging voltage VF, the ceramic capacitance value C and the discharge current value I2, specifically XF=PC*I2*TF / C.

[0129] It should be emphasized that since two unknowns, the duty cycle and the duration, need to be determined, the present embodiment can flexibly set the duty cycle and the duration so that they satisfy the above equations and the vibration amplitude of the piezoelectric ceramic 4 satisfies the preset vibration amplitude.

[0130] It should also be emphasized that when the capacitance value of the piezoelectric ceramic 4 is adjusted, the corresponding charging duty cycle PC, charging time TC, corresponding discharge duty cycle PF and discharge time TF can also be calculated in the above manner to generate corresponding charging signals and discharge signals, so that different piezoelectric ceramics 4 can all perform vibration feedback according to the above preset vibration amplitude.

[0131] Continue based on Figure 1 and Figure 2 , and based on the above embodiments, a third embodiment of the driving circuit of the present application is proposed.

[0132] In order to obtain the ceramic capacitance value of the piezoelectric ceramic 4, in this embodiment, the control module 1 is further configured to output a first detection signal to the first constant current module 2 according to a preset charging time when the power is first turned on, so that the first constant current module 2 charges the piezoelectric ceramic 4 according to the first detection signal;

[0133] The control module 1 is further configured to collect the port voltage of the piezoelectric ceramic 4 after charging, and determine the ceramic capacitance value of the piezoelectric ceramic 4 according to the charging current value, the port voltage, and the preset charging time.

[0134] It should be noted that the first detection signal may be a signal for charging the piezoelectric ceramic 4 according to a predetermined charging time. The predetermined charging time can be set according to actual conditions and is not limited in this embodiment. For the convenience of subsequent description, the predetermined charging time is referred to as T1 in this embodiment.

[0135] It is understandable that the port voltage may be the voltage across the piezoelectric ceramic 4 , which may be acquired by the acquisition module 8 , or may be acquired by other means, which is not limited in this embodiment.

[0136] In actual use, when the control module 1 is powered on for the first time, it is generally initialized. At this time, the control module 1 can first output the above-mentioned first detection signal to the first constant current module 2, and the first constant current module 2 can charge the piezoelectric ceramic 4 according to the preset charging time T1 corresponding to the first detection signal, that is, the charging time of the piezoelectric ceramic 4 is T1. After charging is completed, the control module 1 can collect the voltage across the piezoelectric ceramic 4 as the above-mentioned port voltage. For the convenience of subsequent description, the port voltage is recorded as V. After obtaining the port voltage V, the control module 1 can calculate the ceramic capacitance value C of the piezoelectric ceramic 4 based on the charging current value I1, the port voltage V and the preset charging time T1, specifically C=I1*T1 / V.

[0137] Furthermore, considering that after the ceramic capacitance value of the piezoelectric ceramic 4 is determined, the piezoelectric ceramic 4 is fully charged and needs to be discharged before use in order to facilitate subsequent vibration. Therefore, in this embodiment, the control module 1 is further configured to output a second detection signal to the second constant current module 6 according to a preset discharge duration after obtaining the ceramic capacitance value, so that the second constant current module 6 discharges the piezoelectric ceramic 4 according to the second detection signal;

[0138] The preset charging time is T1, the preset discharging time is T2, the charging current value is I1, the discharging current value is I2, and T2>T1*I1 / I2.

[0139] It should be understood that the second detection signal may be a signal for discharging the piezoelectric ceramic 4 according to a predetermined discharge duration. The predetermined discharge duration may be set according to actual circumstances and is not limited in this embodiment. For ease of description, the predetermined discharge duration is referred to as T2 in this embodiment.

[0140] In actual use, after the control module 1 obtains the ceramic capacitance value C of the piezoelectric ceramic 4, it can output a second detection signal with a preset discharge duration T2 to the second constant current module 6, causing the piezoelectric ceramic 4 to discharge. The discharge duration is T2, so that subsequent vibration feedback can be performed after the discharge is completed. To ensure complete discharge, in this embodiment, T2*I2>T1*I1, that is, T2>T1*I1 / I2.

[0141] In addition, to achieve the above-mentioned purpose, an embodiment of the present application further provides a key, which includes a piezoelectric ceramic 4 and the driving circuit as described above.

[0142] It should be noted that the above-mentioned key in the embodiment can be any key for vibration feedback, and the key can further include other components such as the power supply load 5, and the embodiment is not limited in this regard. The specific implementation of the piezoelectric ceramic 4, the power supply load 5, and the driving circuit can refer to the above-mentioned embodiments of the driving circuit, and the embodiment is not limited in this regard.

[0143] It should be emphasized that since the specific implementation of the key in the embodiment can refer to the above-mentioned embodiments of the driving circuit, the key in the embodiment can have all the beneficial effects achieved by the above-mentioned embodiments of the driving circuit, and the embodiment is not described in detail.

[0144] In addition, to achieve the above-mentioned purpose, the embodiment of the present application further provides an electronic device, which includes the key as described above.

[0145] It should be noted that the above-mentioned electronic device in the embodiment can be any electronic device with the above-mentioned key, such as smart glasses, smart bracelets, etc., and the embodiment is not limited in this regard.

[0146] It should be emphasized that since the specific implementation of the electronic device in the embodiment can refer to the above-mentioned embodiments of the key, the electronic device in the embodiment can have all the beneficial effects achieved by the above-mentioned embodiments of the key, and the embodiment is not described in detail.

[0147] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A driving circuit, characterized in that: The driving circuit includes: a control module and a first constant current module; The control module is connected to the first constant current module, the first constant current module is further connected to a power supply and a piezoelectric ceramic, and the power supply is further connected to a power supply load; The power supply is configured to output a power supply current to the power supply load and output a charging current to the first constant current module; The control module is configured to output a charging signal to the first constant current module; The first constant current module is used to control the charging current according to the charging signal, and transmit the constant charging current to the piezoelectric ceramic for charging, so as to reduce the fluctuation of the power supply current.

2. The driving circuit according to claim 1, wherein: The driving circuit further includes: a second constant current module; The second constant current module is connected to the ground terminal, the piezoelectric ceramic and the control module respectively; The control module is further configured to output a discharge signal to the second constant current module; The second constant current module is used to constant the discharge current output by the charged piezoelectric ceramic according to the discharge signal, and to output the constant discharge current to the ground terminal so as to enable the piezoelectric ceramic to perform vibration feedback.

3. The driving circuit according to claim 2, wherein: The control module is further configured to obtain preset vibration information of the piezoelectric ceramic; The control module is further configured to obtain the ceramic capacitance value of the piezoelectric ceramic, the charging current value of the constant current charging current, and the discharging current value of the constant current discharging current; The control module is further configured to generate a charging signal according to the preset vibration information, the ceramic capacitance value, and the charging current value, and to generate a discharging signal according to the preset vibration information, the ceramic capacitance value, and the discharging current value; The control module is further configured to transmit the charging signal to the first constant current module and transmit the discharging signal to the second constant current module, so that the piezoelectric ceramic performs vibration feedback according to the preset vibration information.

4. The driving circuit according to claim 3, wherein: The preset vibration information includes: a preset vibration speed; The control module is further configured to determine a corresponding preset charging slope and a preset discharging slope according to the preset vibration speed; The control module is further configured to determine a charge duty cycle according to the preset charge slope, the ceramic capacitance value, and the charge current value, and to determine a discharge duty cycle according to the preset discharge slope, the ceramic capacitance value, and the discharge current value; The control module is further configured to generate a charging signal according to the charging duty cycle, and generate a discharging signal according to the discharging duty cycle.

5. The driving circuit according to claim 3, wherein: The preset vibration information includes: a preset vibration amplitude; The control module is further configured to determine a corresponding preset charging voltage and a preset discharging voltage according to the preset vibration amplitude; The control module is further configured to determine a charging duty cycle and a charging duration according to the preset charging voltage, the ceramic capacitance value, and the charging current value, and to determine a discharge duty cycle and a discharge duration according to the preset discharge voltage, the ceramic capacitance value, and the discharge current value; The control module is further configured to generate a charging signal according to the charging duty cycle and the charging duration, and to generate a discharging signal according to the discharging duty cycle and the discharging duration.

6. The driving circuit according to claim 3, wherein: The control module is further configured to output a first detection signal to the first constant current module according to a preset charging duration when the power is first turned on, so that the first constant current module charges the piezoelectric ceramic according to the first detection signal; The control module is further configured to collect the port voltage of the piezoelectric ceramic after charging, and determine the ceramic capacitance value of the piezoelectric ceramic according to the charging current value, the port voltage, and the preset charging time.

7. The driving circuit according to claim 6, wherein: The control module is further configured to, after obtaining the ceramic capacitance value, output a second detection signal to the second constant current module according to a preset discharge duration, so that the second constant current module discharges the piezoelectric ceramic according to the second detection signal; The preset charging time is T1, the preset discharging time is T2, the charging current value is I1, the discharging current value is I2, and T2>T1*I1 / I2.

8. The driving circuit according to any one of claims 2 to 7, wherein: The driving circuit further includes: a first current limiting module and a second current limiting module; The first current limiting module is connected to the control module and the first constant current module respectively, and the second current limiting module is connected to the control module and the second constant current module respectively; The first current limiting module is configured to limit the current of the charging signal output by the control module and transmit the current-limited charging signal to the first constant current module; The second current limiting module is used to limit the current of the discharge signal output by the control module and transmit the current-limited discharge signal to the second constant current module.

9. A button, characterized in that: The key comprises piezoelectric ceramics and a driving circuit according to any one of claims 1 to 8.

10. An electronic device, characterized in that: The electronic device comprises the key according to claim 9.

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