Constant-current driving circuit and electronic equipment

Abstract

The utility model discloses a constant current drive circuit and electronic equipment, which are applied to the field of electronic hardware. Wherein the first end of the driving circuit is connected with the controller, the second end of the driving circuit is connected with the first end of each constant-current feedback circuit, the third end of the driving circuit is connected with the first power supply, and the driving circuit is used for converting a voltage signal sent by the controller into a driving signal and sending the driving signal to each constant-current feedback circuit; the second end of each constant current feedback circuit is connected with the second power supply through the corresponding diode, and is used for controlling the corresponding diode to drive according to the obtained driving signal. Therefore, each diode corresponds to one constant-current feedback circuit, and driving of different colors and brightness of the diodes connected with the constant-current feedback circuits can be controlled through one driving circuit. The constant current driving circuit provided by the utility model is simple in structure, can save the material cost during circuit design, saves the pin resources of the controller, and saves the space of a printed circuit board.

Description

Technical Field

[0001] This utility model relates to the field of electronic hardware, and in particular to a constant current drive circuit and electronic device. Background Technology

[0002] A light-emitting diode (LED) is a semiconductor diode made of compounds containing gallium, arsenic, phosphorus, nitrogen, etc., that can convert electrical energy into light energy. When electrons and holes recombine inside, it can radiate visible light. Therefore, it is usually used as an indicator light in circuits and instruments, or to form text or numbers for display.

[0003] Currently, large instruments typically use multiple LEDs of varying brightness to display different operating states. However, in practical applications, because the brightness and color of LEDs are different, each LED corresponds to a control system. Having multiple control systems leads to problems such as a large number of electronic components, high material costs, a large number of microcontroller (MCU) pin resources, and a large footprint on printed circuit boards (PCBs).

[0004] In view of the above-mentioned technology, finding a constant current drive circuit is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] The purpose of this invention is to provide a constant current drive circuit and electronic device that can simultaneously drive multiple diodes with different colors and brightness while saving material costs and printed circuit board space.

[0006] To solve the above-mentioned technical problems, on the one hand, the present invention provides a constant current driving circuit, including: a driving circuit and at least two constant current feedback circuits;

[0007] The first end of the drive circuit is connected to the controller, the second end of the drive circuit is connected to the first end of each constant current feedback circuit, and the third end of the drive circuit is connected to the first power supply. It is used to convert the voltage signal sent by the controller into a drive signal and send the drive signal to each constant current feedback circuit.

[0008] The second terminal of each constant current feedback circuit is connected to the second power supply through a corresponding diode, which is used to control the corresponding diode drive according to the acquired drive signal.

[0009] Preferably, the driving circuit includes: a first switching transistor and a second switching transistor;

[0010] In this circuit, the control terminal of the first switch is connected to the controller as the first terminal of the drive circuit, the first terminal of the first switch is connected to the control terminal of the second switch, and the second terminal of the first switch is grounded.

[0011] The first terminal of the second switch is connected to the first power supply as the third terminal of the drive circuit, and the second terminal of the second switch is connected to the first terminal of each constant current feedback circuit as the second terminal of the drive circuit.

[0012] Preferably, it further includes: a voltage configuration circuit;

[0013] The first terminal of the voltage configuration circuit is connected to the second terminal of the drive circuit.

[0014] The second terminal of the voltage configuration circuit is connected to the first terminal of each constant current feedback circuit.

[0015] Preferably, the voltage configuration circuit includes: a first resistor and a second resistor;

[0016] In this circuit, the first end of the first resistor is connected to the second end of the driving circuit as the first end of the voltage configuration circuit.

[0017] The second end of the first resistor is connected to the first end of the second resistor, and together they serve as the second end of the voltage configuration circuit, which is connected to the first end of each constant current feedback circuit.

[0018] The second terminal of the second resistor is grounded.

[0019] Preferably, the constant current feedback circuit includes: a third switching transistor and a third resistor;

[0020] Among them, the control terminal of the third switch is connected to the first terminal of the constant current feedback circuit, the first terminal of the second resistor, and the second terminal of the first resistor.

[0021] The first terminal of the third switching transistor serves as the second terminal of the constant current feedback circuit and is connected to the second power supply through the corresponding diode.

[0022] The second terminal of the third switch is connected to the first terminal of the third resistor;

[0023] The second terminal of the third resistor is grounded.

[0024] Preferably, the first switching transistor is a first transistor, and the first transistor is an NPN transistor;

[0025] Among them, the base of the first transistor is connected to the controller as the control terminal of the first switching transistor;

[0026] The collector of the first transistor is connected to the control terminal of the second switch as the first terminal of the first switch.

[0027] The emitter of the first transistor is grounded as the second terminal of the first switching transistor.

[0028] Preferably, the second switching transistor is a second transistor, and the second transistor is a PNP type transistor;

[0029] In this configuration, the base of the second transistor serves as the control terminal of the second switching transistor and is connected to the first terminal of the first switching transistor.

[0030] The emitter of the second transistor is connected to the first power supply as the first terminal of the second switching transistor.

[0031] The collector of the second transistor is connected to the first terminal of each constant current feedback circuit as the second terminal of the second switch.

[0032] Preferably, the third switching transistor is a third transistor, and the third transistor is an NPN transistor;

[0033] In this configuration, the base of the third transistor serves as the control terminal of the third switching transistor and is connected to the second terminal of the first resistor and the first terminal of the second resistor.

[0034] The collector of the third transistor serves as the first terminal of the third switching transistor and is connected to the second power supply through a corresponding diode.

[0035] The emitter of the third transistor is connected to the first terminal of the third resistor as the second terminal of the third switching transistor.

[0036] Preferably, the third resistor is a variable resistor.

[0037] On the other hand, this application also provides an electronic device including the aforementioned constant current drive circuit.

[0038] This utility model provides a constant current driving circuit, comprising: a driving circuit and at least two constant current feedback circuits; wherein, the first terminal of the driving circuit is connected to a controller, the second terminal of the driving circuit is connected to the first terminal of each constant current feedback circuit, and the third terminal of the driving circuit is connected to a first power supply, used to convert the voltage signal sent by the controller into a driving signal and send the driving signal to each constant current feedback circuit; the second terminal of each constant current feedback circuit is connected to a second power supply through a corresponding diode, used to control the driving of the corresponding diode according to the acquired driving signal. Thus, in this application, each diode corresponds to one constant current feedback circuit, and the entire circuit has only one driving circuit. A single driving circuit can control the driving of each diode connected to the constant current feedback circuit, each with different colors and brightness. The constant current driving circuit provided in this application has a simple structure, saving material costs in circuit design, saving pin resources of the controller, and saving space on the printed circuit board. Attached Figure Description

[0039] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A schematic diagram of a constant current drive circuit provided in an embodiment of this application;

[0041] Figure 2 A circuit diagram of a constant current drive circuit provided for an embodiment of this application;

[0042] Figure 3 This is a schematic diagram of negative feedback constant current drive provided in an embodiment of this application. Detailed Implementation

[0043] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0044] The core of this invention is to provide a constant current drive circuit and an electronic device.

[0045] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Figure 1 A schematic diagram of a constant current driving circuit provided in an embodiment of this application is shown in the figure. It includes: a driving circuit 1 and at least two constant current feedback circuits (2¹-2N, where N is an integer greater than 2). In addition, Figure 1 It also includes: controller 3, diodes (D1-DN). Figure 1 The connection relationship of the constant current drive circuit shown is as follows: the first end of the drive circuit 1 is connected to the controller 3, the second end of the drive circuit 1 is connected to the first end of each constant current feedback circuit (21-2N), and the third end of the drive circuit 1 is connected to the first power supply V1; the second end of each constant current feedback circuit (21-2N) is connected to the second power supply V2 through the corresponding diode (D1-DN).

[0047] In a specific embodiment, the controller 3 is connected to the drive circuit 1 and is used to send a voltage signal (DC signal or PWM signal) to the drive circuit 1. If the drive circuit 1 detects a high-level voltage signal, the drive circuit 1 is turned on, and the first voltage VCC provided by the first power supply V serves as the start-up voltage for each constant current feedback circuit (21-2N). If the drive circuit 1 detects a low-level voltage signal, the drive circuit 1 is turned off, and the entire constant current drive circuit is turned off. In the constant current feedback circuit (21-2N), if the start-up voltage is obtained, different drive circuits are provided for the connected diodes (D1-DN) based on the relevant parameters of the device itself, thereby ensuring that each diode in the constant current drive circuit provided in this application can simultaneously display different colors and different brightness.

[0048] Since the constant current drive circuit provided in this application is specifically used in large instruments, electronic equipment, and rail transportation, the controller 3 can be a microcontroller unit, control chip, etc.; the first power supply V can be the first voltage VCC of the power chip, which is the voltage provided by the power chip; the second power supply V2 can be a car battery, so the second voltage Vbattery provided by the second power supply V2 can be the voltage provided by the car battery.

[0049] This utility model provides a constant current driving circuit, comprising: a driving circuit and at least two constant current feedback circuits; wherein, the first terminal of the driving circuit is connected to a controller, the second terminal of the driving circuit is connected to the first terminal of each constant current feedback circuit, and the third terminal of the driving circuit is connected to a first power supply, used to convert the voltage signal sent by the controller into a driving signal and send the driving signal to each constant current feedback circuit; the second terminal of each constant current feedback circuit is connected to a second power supply through a corresponding diode, used to control the driving of the corresponding diode according to the acquired driving signal. Thus, in this application, each diode corresponds to one constant current feedback circuit, and the entire circuit has only one driving circuit. A single driving circuit can control the driving of each diode connected to the constant current feedback circuit, each with different colors and brightness. The constant current driving circuit provided in this application has a simple structure, saving material costs in circuit design, saving pin resources of the controller, and saving space on the printed circuit board.

[0050] Based on the above embodiments, as a preferred embodiment, the driving circuit 1 includes: a first switching transistor and a second switching transistor, such as... Figure 2 As shown, the first switching transistor is a first transistor Q1, and the first transistor Q1 is an NPN transistor; the second switching transistor is a second transistor Q2, and the second transistor Q2 is a PNP transistor, and... Figure 2TP1, TP2, and TP3 are all voltage detection points. Therefore, the connection relationship of its driving circuit 1 is as follows: the control terminal of the first switch (the base of the first transistor Q1) is connected to the controller 3 as the first terminal of the driving circuit 1; the first terminal of the first switch (the collector of the first transistor Q1) is connected to the control terminal of the second switch (the base of the second transistor Q2); the second terminal of the first switch (the emitter of the first transistor Q1) is grounded; the first terminal of the second switch (the emitter of the second transistor Q2) is connected to the first power supply V1 as the third terminal of the driving circuit 1; and the second terminal of the second switch (the collector of the second transistor Q2) is connected to the first terminal of each constant current feedback circuit (21-2N) as the second terminal of the driving circuit 1.

[0051] In addition, to ensure the current during startup of the constant current feedback circuit (21-2N), a voltage configuration circuit is added between the drive circuit 1 and the constant current feedback circuit (21-2N). For example... Figure 2 As shown, its voltage configuration circuit includes: a first resistor RS and a second resistor RD. The circuit connection is as follows: the first end of the first resistor RS is connected to the second end of the drive circuit 1 as the first end of the voltage configuration circuit; the second end of the first resistor RS is connected to the first end of the second resistor RD, and together they are connected to the first end of each constant current feedback circuit (21-2N) as the second end of the voltage configuration circuit; the second end of the second resistor RD is grounded.

[0052] In a specific embodiment, controller 3 is connected to drive circuit 1 and is used to control the on / off state of subsequent diodes (D1-DN). The specific principle is as follows: When controller 3 outputs a high-level signal (5V voltage), TP1 is high. At this time, the first transistor Q1 and the second transistor Q2 are turned on, making the voltage value of TP2 approximately equal to the first voltage VCC provided by the first power supply V1. Taking VCC=5V and the resistance values ​​Rs of the first resistor RS and Rd of the second resistor RD as an example, TP3=2.5V. At this time, all constant current feedback circuits (21-2N) are turned on, and diodes D1-DN are lit. When controller 3 outputs a low-level signal (0V voltage), TP1 is low. The first transistor Q1 and the second transistor Q2 are turned off, making TP3=TP2=0V. At this time, all constant current feedback circuits (21-2N) are turned off, and diodes D1-DN are turned off.

[0053] Based on this, since each constant current feedback circuit (21-2N) includes a third switching transistor and a third resistor, and the third switching transistor is a third NPN transistor, while the third resistor is a variable resistor, therefore its... Figure 2The third transistor shown is Q31-Q3N, and the variable resistor is R1-RN. The connection relationship of its constant current feedback circuit (21-2N) is as follows: the control terminal of the third switching transistor (the base of the third transistor Q31-Q3N) is connected to the first terminal of the corresponding constant current feedback circuit (21-2N) and the first terminal of the second resistor Rd and the second terminal of the first resistor Rs; the first terminal of the third switching transistor (the collector of the third transistor Q31-Q3N) is connected to the second power supply through the corresponding diode (D1-DN); the second terminal of the third switching transistor (the emitter of the third transistor Q31-Q3N) is connected to the first terminal of the third resistor (variable resistor R1-RN); the second terminal of the third resistor (variable resistor R1-RN) is grounded.

[0054] In a specific embodiment, taking the first constant current feedback circuit 21 as an example, it internally includes a third transistor Q31, a variable resistor R1, and is connected to a diode D1. Its maximum operating current... ,in, Characterizing the threshold voltage of diode D1, Characterizing the threshold voltage of transistor Q31, The resistance value of the variable resistor R1 is represented. The maximum operating current value I corresponds to the maximum brightness of diode D1, that is, the maximum brightness when the signal duty cycle is 100%, at which point the operating current is I. Therefore, the diode brightness can be adjusted by changing the duty cycle of the PWM signal. For example, during the day, the diode brightness is set to maximum, i.e., the PWM duty cycle is set to 100%; at night, the PWM duty cycle is adjusted to 50%, i.e., the diode brightness is reduced to 50%.

[0055] Meanwhile, taking the first constant current feedback circuit 21 as an example, the Vbattery voltage range is 9V~16V. For example... Figure 3 As shown, the Ic circuit represents the current flowing through diode D1; the Ie current is the current flowing through variable resistor R1; the Ib current is the current flowing through transistor Q31; Vb voltage is the voltage at the base of transistor Q31; Ve voltage is the voltage at the emitter of transistor Q31; and Vbe is the voltage difference between the base and emitter. Under normal operation, Vbattery = 12V. If Vbattery voltage increases, the Ic current increases, and the Ie current increases. The increase in Ie current, in turn, controls the Ve voltage to increase. Since Vb is a fixed value, and Vbe = Vb - Ve, Vbe decreases. According to the volt-ampere characteristic, a decrease in Vbe leads to a decrease in Ib, and vice versa, thus achieving negative feedback. That is, when the supply voltage Vbattery fluctuates, the circuit can automatically adjust to maintain a constant current in diode D1-DN, i.e., maintain a constant brightness in diode D1-DN, thereby preventing diode D1-DN from flickering.

[0056] In this design, the variable resistors R1-RN are configured to provide the corresponding operating currents for the diodes D1-DN. When used as variable resistors, different operating currents can be configured for the diodes at any time. Furthermore, the constant current drive circuit provided in this application meets automotive-grade EMC requirements and will not oscillate due to parasitic parameters even when the signal source is at a long distance, making it directly applicable to automobiles.

[0057] It should be noted that the embodiments provided in this application are only one possible implementation method, but are not limited to this only implementation method. Users can set their own implementation methods according to their needs.

[0058] This utility model provides a constant current driving circuit, comprising: a driving circuit and at least two constant current feedback circuits; wherein, the first terminal of the driving circuit is connected to a controller, the second terminal of the driving circuit is connected to the first terminal of each constant current feedback circuit, and the third terminal of the driving circuit is connected to a first power supply, used to convert the voltage signal sent by the controller into a driving signal and send the driving signal to each constant current feedback circuit; the second terminal of each constant current feedback circuit is connected to a second power supply through a corresponding diode, used to control the driving of the corresponding diode according to the acquired driving signal. Thus, in this application, each diode corresponds to one constant current feedback circuit, and the entire circuit has only one driving circuit. This single driving circuit can control the driving of each diode connected to the constant current feedback circuit, each with different colors and brightness. The constant current driving circuit provided in this application has a simple structure, saving material costs in circuit design, saving pin resources of the controller, and saving space on the printed circuit board; furthermore, it allows for real-time brightness control and adjustment of the diodes to prevent diode flickering.

[0059] On the other hand, this application also provides an electronic device including the aforementioned constant current drive circuit, and having the same beneficial effects. Since the embodiments provided in this application are the same as the embodiments of the aforementioned constant current drive circuit, they will not be described in detail here.

[0060] The constant current drive circuit and electronic device provided by this utility model have been described in detail above. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

[0061] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A constant current drive circuit, characterized in that, include: The driving circuit and at least two constant current feedback circuits; The first end of the driving circuit is connected to the controller, the second end of the driving circuit is connected to the first end of each constant current feedback circuit, and the third end of the driving circuit is connected to the first power supply. The driving circuit is used to convert the voltage signal sent by the controller into a driving signal and send the driving signal to each constant current feedback circuit. The second terminal of each constant current feedback circuit is connected to the second power supply through a corresponding diode, and is used to control the corresponding diode drive according to the acquired drive signal.

2. The constant current drive circuit according to claim 1, characterized in that, The driving circuit includes: a first switching transistor and a second switching transistor; Wherein, the control terminal of the first switch is connected to the controller as the first terminal of the drive circuit, the first terminal of the first switch is connected to the control terminal of the second switch, and the second terminal of the first switch is grounded. The first terminal of the second switch is connected to the first power supply as the third terminal of the driving circuit, and the second terminal of the second switch is connected to the first terminal of each constant current feedback circuit as the second terminal of the driving circuit.

3. The constant current drive circuit according to claim 1, characterized in that, Also includes: Voltage configuration circuit; The first terminal of the voltage configuration circuit is connected to the second terminal of the drive circuit. The second terminal of the voltage configuration circuit is connected to the first terminal of each of the constant current feedback circuits.

4. The constant current drive circuit according to claim 3, characterized in that, The voltage configuration circuit includes: a first resistor and a second resistor; Wherein, the first end of the first resistor is connected to the second end of the driving circuit as the first end of the voltage configuration circuit; The second end of the first resistor is connected to the first end of the second resistor, and together they serve as the second end of the voltage configuration circuit and are connected to the first end of each of the constant current feedback circuits; The second terminal of the second resistor is grounded.

5. The constant current drive circuit according to claim 4, characterized in that, The constant current feedback circuit includes: a third switching transistor and a third resistor; The control terminal of the third switch is connected to the first terminal of the constant current feedback circuit and the first terminal of the second resistor and the second terminal of the first resistor. The first terminal of the third switching transistor serves as the second terminal of the constant current feedback circuit and is connected to the second power supply through the corresponding diode. The second terminal of the third switch is connected to the first terminal of the third resistor; The second terminal of the third resistor is grounded.

6. The constant current drive circuit according to claim 2, characterized in that, The first switching transistor is a first transistor, and the first transistor is an NPN transistor; The base of the first transistor is connected to the controller as the control terminal of the first switching transistor. The collector of the first transistor is connected to the control terminal of the second switch as the first terminal of the first switch. The emitter of the first transistor is grounded as the second terminal of the first switching transistor.

7. The constant current drive circuit according to claim 2, characterized in that, The second switching transistor is a second transistor, and the second transistor is a PNP type transistor; The base of the second transistor serves as the control terminal of the second switch and is connected to the first terminal of the first switch. The emitter of the second transistor serves as the first terminal of the second switching transistor and is connected to the first power supply. The collector of the second transistor is connected to the first terminal of each constant current feedback circuit as the second terminal of the second switch.

8. The constant current drive circuit according to claim 5, characterized in that, The third switching transistor is a third transistor, and the third transistor is an NPN transistor; Wherein, the base of the third transistor serves as the control terminal of the third switching transistor and is connected to the second terminal of the first resistor and the first terminal of the second resistor; The collector of the third transistor serves as the first terminal of the third switching transistor and is connected to the second power supply through the corresponding diode. The emitter of the third transistor is connected to the first terminal of the third resistor as the second terminal of the third switching transistor.

9. The constant current drive circuit according to claim 5, characterized in that, The third resistor is a variable resistor.

10. An electronic device, characterized in that, Includes the constant current drive circuit as described in any one of claims 1-9.

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