CN201119073Y - Constant-current general control driving device for automobile background light - Google Patents

Abstract

The utility model claims to protect a driving system and a driving control method for the constant current of the background light of an automobile, and relates to the field of electronic technology. Drive, so that each LED light source that makes up the car background light has a consistent working current, and use the module adjustment device and the comprehensive adjustment device to adjust the output current of the adjustable constant current source LED driver module used by a single component or multiple components. The output currents of these modules are kept changing synchronously, so that the chromaticity and brightness of the car background light are kept changing synchronously when the brightness is adjusted as a whole, and the purpose of effectively controlling the quality of the car background light source is realized. The utility model can be used as a control system for the chromaticity and brightness of the background light of the automobile.

Description

A driving device for constant current master control of automobile background light

technical field

The utility model relates to the field of electronic technology, in particular to the drive control and related technology of LED light source for automobile background light.

Background technique

Functional components such as instrumentation, control buttons, knobs, and switches inside the car provide a luminous lighting system for lighting and indicating functions. The light source is usually designed and installed inside the corresponding component, and the luminous characters with specific meanings are displayed by transmitting light outward. , glowing figures or figure outlines. The components in the car with backlight luminous indicator lighting system usually include instrument cluster, air conditioning controller, CD player, combination switch and so on.

At present, the light-emitting devices used in the backlight of automobiles are mainly light-emitting diodes (LEDs). In addition to a single button and switch, a component with backlight is usually designed with multiple light-emitting diodes as the backlight source. Generally, there are 30 to 50 light-emitting diodes used as background light sources in a car. To improve the quality of the background light of the car, we must first start with the problem of the light source. As the LED of the car background light source, its correct and effective driving method is to ensure the quality of the car background light source. At present, the driving method used by automotive backlight LEDs is to use a resistor R as a current limiting resistor to connect one or more LEDs in series, calculate the required resistance value through the working current of the LED, and then connect all the LEDs and their limiting resistors. The current resistors are connected in parallel for unified power supply, and the power supply is fixed or adjustable, as shown in Figure 1. Since the LED is a current-type device, and the resistance precision of the series connected resistors is difficult to ensure consistency, it is difficult to make the current flowing through each LED basically the same through the method of connecting the resistors in series, so that it is difficult to ensure that the luminous brightness of each LED is consistent; When the voltage is high, due to the change of the working point of the LED, and due to the difference in resistance, each LED will change differently, and there will be obvious confusion in chromaticity and brightness. Therefore, the driving method used for the automobile backlight LED in the prior art cannot effectively control the quality of the automobile backlight light source.

Contents of the invention

The utility model aims at the above-mentioned problems existing in the design of the current automobile background light drive circuit, and designs a constant current master control drive device for the automobile background light. It can effectively improve the consistency of the chromaticity and brightness of the background light of the car, and the user can also conveniently adjust the brightness of the background light of the car according to the brightness of the environment, and can maintain the uniform change of the brightness.

The technical solution of the utility model to solve the above-mentioned technical problems is to design a driving device for constant current control of automobile background light, which is composed of an adjustable constant current source LED drive module, a comprehensive adjustment unit and a module adjustment unit, wherein the adjustable constant current The current LED drive module has multiple outputs, which can provide consistent drive current for multiple LED light sources at the same time; the output terminals of multiple adjustable constant current source LED drive modules are respectively connected to the negative terminals of a series of LED light sources to provide them with consistent Drive current, the output terminals of multiple sub-module adjustment units are respectively connected to the control terminal of an adjustable constant current source LED driver module, and the output terminals of the integrated adjustment unit are respectively connected to the control terminals of multiple module adjustment units and multiple adjustable constant current source LED drivers Module control terminal.

The module adjustment unit adjusts the output current of a single adjustable constant current LED drive module, so as to achieve the purpose of adjusting the LED drive current driven by the module. The comprehensive adjustment unit can adjust the output current of a single or multiple constant current source LED drive modules. In this way, the current of LEDs of each driving module can be adjusted.

The constant current source LED drive module includes a series of parallel unit adjustment drive circuits for adjusting current or voltage. Each unit adjustment drive circuit is composed of a crystal triode series constant current source.

The integrated adjustment unit and the sub-module adjustment unit have built-in linear adjustable resistors, and the output terminal is connected to the control terminal of the constant current source, and the output current of the constant current source is continuously adjusted by adjusting the current or voltage.

Beneficial effects of the utility model: the utility model utilizes a plurality of adjustable constant current source LED drive modules to drive the LEDs of the various parts of the automobile background light, so that each LED light source forming the automobile background light has a consistent working current, and the module The adjustment device and the comprehensive adjustment device adjust the output current of the adjustable constant current source LED drive module used by a single component or multiple components, so that the output current of these modules keeps changing synchronously, so that the car background light is on the whole When the brightness is adjusted, the synchronous change of chromaticity and brightness is maintained to achieve the purpose of effectively controlling the quality of the car background light source.

Description of drawings

Figure 1 is a schematic diagram of the commonly used automotive backlight LED drive circuit;

The schematic block diagram of the circuit of the automobile background light driving device proposed by the utility model in Fig. 2;

Figure 3 schematic block diagram of the circuit principle of the constant current LED drive module;

Figure 4 is a schematic block diagram of a typical constant current source circuit;

Specific implementation

The utility model proposes an automobile background light constant current total control driving device, which uses a plurality of adjustable constant current source LED drive modules to drive the background light source LEDs of various parts of the automobile, so that each LED light source that forms the automobile background light has a consistent working current, use the module adjustment unit and the comprehensive adjustment unit to adjust the output current of the adjustable constant current source LED driver module used by a single component or multiple components, so that the output current of these modules keeps changing synchronously, so that the overall The car background light can maintain the synchronous change of chromaticity and brightness when the brightness is adjusted, and realize the purpose of effectively controlling the quality of the car background light source.

The implementation of the utility model will be specifically described below with reference to the accompanying drawings and specific embodiments.

Fig. 2 shows the electric principle block diagram of the automobile background light drive device of the present invention, the device is composed of an adjustable constant current source LED drive module, a comprehensive adjustment unit and a sub-module adjustment unit, and the power supply is connected to a series of positive terminals of LED indicator lights and The power supply terminal of each constant current source LED driver module provides working power for the device. Among them, the adjustable constant current source LED driver module has multiple outputs, and the output terminals of multiple adjustable constant current source LED driver modules are respectively connected to a series of LED indicators. The negative terminal of the lamp can provide a consistent driving current for multiple LEDs at the same time; the output terminals of each module adjustment unit are connected to the control terminal of an adjustable constant current source LED driver module, and the output terminals of the integrated adjustment unit are respectively connected to multiple sub-modules The control terminal of the adjustment unit and the control terminal of multiple adjustable constant current source LED drive modules, each sub-module adjustment unit adjusts the output current of a single constant current source LED drive module, so as to achieve the purpose of synchronously adjusting the LED drive current driven by the module ; The comprehensive adjustment unit can adjust the output current of one or more constant current source LED drive modules, so as to adjust the current of each drive module LED, so that the output current of these modules can keep changing synchronously, so that the overall brightness of the car background light can be adjusted. Keep the synchronous change of chromaticity and brightness when adjusting.

FIG. 3 is a schematic diagram of the circuit principle of the constant current source LED driver module. The adjustable constant current source LED driver module 6 is inside the dotted line box, including the output of the adjusting device to control the driving current. The constant current source LED drive module consists of a series of unit adjustment drive circuits connected in parallel. The unit adjustment drive circuit is used to adjust current or voltage. Each unit adjustment drive circuit is composed of a series branch of a transistor and a constant current source. The specific circuit is as follows: Figure 3 shows.

The output terminal of the power supply 1 is connected to the bases of a series of NPN transistors 2, the emitters of a series of transistors are grounded, the collectors are connected to the negative pole of the LED light-emitting diode 7 through a constant current source, and the base of the transistors is connected to the power supply. The current output of each channel of the current source LED driver module;

The control end of the constant current source 3 is connected to the output end of the sub-module adjustment unit 4, and the sub-module adjustment unit 4 has a built-in linear adjustable resistor, which is connected in series with the control end of the constant current source LED driver module, and the integrated adjustment unit 5 also has a built-in linear The adjustable resistor is connected in series with the adjustable resistor in the sub-module adjusting unit, and the resistance value of the adjustable resistor in the sub-module adjusting unit 4 can be changed to adjust the output current of the controlled constant current source LED driver module. By adjusting the resistance value of the resistor, the output current of multiple constant current source drive modules connected together can be adjusted. The output current of each constant current source LED drive module is synchronously adjusted by the adjustment unit, so that the drive current output to each LED light source is basically consistent.

The constant current source LED drive module can be a constant current source LED drive circuit composed of discrete components, or an LED drive circuit composed of integrated LED drive chips. The dotted line in Figure 4 is a typical constant current source drive composed of discrete components. Schematic diagram of the circuit principle.

The non-inverting input terminal of the operational amplifier 8 is respectively connected to the voltage dividing resistor R1 and the adjustable resistors R2 and R3 in the adjustment devices 4 and 5, and the voltage dividing resistor R1 provides power for it, and the inverting input terminal of the operational amplifier is connected to the emission of the NPN transistor Q1 pole, resistor R and R4 are connected to the common terminal, the output terminal of the operational amplifier is connected to the gate of the field effect transistor T1, the drain of the field effect transistor is connected to the collector of the triode Q1, and connected to the negative terminal of the light-emitting diode LED, the field effect The source of the transistor Q1 is connected to the base of the transistor Q1 and the other end of the resistor R4; the current sink of the constant current source driving circuit is proportional to the voltage of the non-inverting input terminal of the operational amplifier 8 and inversely proportional to the resistor R. When the output power increases or decreases Hours, the feedback voltage input by the inverting terminal of the operational amplifier also increases or decreases, so that the output voltage of the operational amplifier decreases or increases, thereby adjusting the current flowing through the field effect transistor T1 and the transistor Q1 to decrease or increase, and to achieve constant regulation The purpose of the current source driving control output current; turn up or down the resistance value of the adjustable resistor in the adjustment unit 4, 5, the voltage applied to the non-inverting input terminal of the operational amplifier 8 will increase or decrease, and the output voltage of the operational amplifier 8 will also increase or decrease. Increase or decrease, so as to adjust the power supply through the field effect tube and the triode, and achieve the purpose of adjusting the constant current source current.

The integrated LED driver chip integrates multiple circuits with the above-mentioned constant current driving function on one chip, and the circuit is more concise.

Automobile background light LED light source Multi-channel adjustable constant current source LED driver module can drive multiple LED light sources at the same time, and keep the driving current output to each LED light source consistent. In the process of adjusting the brightness of the light, the multi-channel constant current source LED drive module is simultaneously adjusted, so that these LED light sources can generate background light with basically the same chromaticity and brightness.

Claims (6)

1. A driving device for constant current control of automobile background light, the driving device is composed of an adjustable constant current source LED drive module, a comprehensive adjustment device and a sub-module adjustment device, it is characterized in that the adjustable constant current source LED driver The module has multiple outputs, and the output terminals of multiple adjustable constant current source LED drive modules are respectively connected to the negative terminals of a series of automotive backlight LED light sources to provide them with a consistent driving current; the output terminals of multiple sub-module adjustment devices are respectively The control terminal of an adjustable constant current source LED drive module is connected, and the output terminal of the comprehensive adjustment device is connected with the control terminals of multiple sub-module adjustment devices and the control terminals of multiple adjustable constant current source LED drive modules. 2. The driving device for constant current master control of automobile backlight according to claim 1, characterized in that the constant current source LED driving module includes a series of parallel unit regulating driving circuits for adjusting current or voltage. 3. The driving device for constant current master control of automobile background light according to claim 2, characterized in that the unit adjustment drive circuit is composed of transistors (2) in series with constant current sources, and the power supply is connected to the base of the transistors (2). pole, the emitter of the triode (2) is grounded, and the collector of the triode (2) is connected to the cathode of the LED light-emitting diode through a constant current source. 4. According to one of the claims 1-3, the driving device for constant current control of automobile background light is characterized in that the sub-module adjustment device and the comprehensive adjustment device have built-in linear adjustable resistors, and the output end is connected to an adjustable constant current source The constant current source control terminal in the LED driver module. 5. The driving device for constant current master control of automotive backlight according to any one of claims 1-3, wherein the adjustable constant current source LED driving module is composed of discrete components or an integrated LED driving chip. 6. The driving device for constant current master control of automobile background light according to claim 5, characterized in that the adjustable constant current source LED drive module composed of discrete components includes: an operational amplifier, a triode Q1, a field effect transistor T1, and The inverting input terminal of the amplifier is connected to the emitter of the transistor Q1, the common terminal connected to the resistors R and _R4 , the output terminal of the operational amplifier is connected to the gate of the field effect transistor, and the drain of the field effect transistor is connected to the collector of the transistor Q1, and is connected with The negative terminal of the light-emitting diode LED is connected, the source of the field effect is connected with the base of the transistor Q1 and the common terminal connected with the resistor R4, and the non-inverting input terminal of the operational amplifier is connected with the output terminal of the comprehensive adjustment device and the sub-module adjustment device through a resistor.

Images