Electronic assemblies and automotive light-emitting devices for automotive light-emitting devices

Abstract

The present invention provides an electronic assembly for an automotive lighting device (10), comprising a light source (1), a driver (3) for controlling the light source (1), and an input protection circuit (2). The input protection circuit (2) is disposed between a power source and the light source (1) and comprises a protection input (21) and a protection output (22). The protection input (21) and the protection output (22) are connected via a resistor group comprising a resistor (23) and a diode (24) connected in series. The node between the protection input (21) and the resistor group is connected to ground via a first capacitor (25), and the node between the resistor group and the protection output (22) is connected to ground via a second capacitor (26).

Description

Technical Field

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[0001] The present invention belongs to the field of electronic configurations for controlling light sources for motor vehicles.

Background Art

[0002] The automotive lighting market can be considered one of the most competitive markets and constantly requires new lighting functions. Some customer trends include the use of RGB (red, green, blue) solid light sources, such as RGB LEDs (light-emitting diodes), to implement the required lighting and signaling functions.

[0003] However, these components and their drivers require special input protection to avoid transient pulses that can exceed the maximum voltage, thereby damaging the components and their drivers and thus causing system malfunctions.

[0004] To prevent this occurrence, transient voltage suppressors are usually employed in the input protection circuit. However, these components are usually heavy, expensive, and large.

[0005] The present invention provides an alternative configuration that provides a controlled group of solid light sources for an electronic assembly for an automotive light-emitting device to overcome these drawbacks.

Summary of the Invention

[0006] The present invention provides an alternative solution for managing the current needs of a light source of an automotive light-emitting device by an electronic assembly for the automotive light-emitting device, the electronic assembly comprising - a light source, - a driver configured to control the operation of the light source, - a power supply configured to provide an electrical supply to the light source and to the driver, <000002- An input protection circuit disposed between a power source and a light source, wherein the input protection circuit is intended to limit transient voltages and / or currents received by the light source and / or the driver, and comprises a protection input and a protection output. Equipped with, - The protection input and protection output are connected by a group of resistors and diodes connected in series, the diodes having an anode terminal and a cathode terminal, - The anode terminal of the diode is connected to the protection input, either directly or via a resistor. - The node between the protection input and the resistor group is connected to ground via the first capacitor. - The node between the resistor group and the protection output is connected to ground via a second capacitor.

[0007] Without requiring expensive, bulky, and space-consuming transient suppressors, this automotive light-emitting device is configured to filter out all hazardous pulses. This is a critical issue for internal lighting RGB modules.

[0008] By connecting the diode's anode terminal to the protection input, current can flow freely towards the module driver while protecting the driver from current inversion.

[0009] Preferably, the cathode terminal of the diode is directly connected to the protection output via a resistor.

[0010] In some specific embodiments, the resistor is located closer to the protection output than the diode.

[0011] This advantageous position, where the resistor is located after the diode in the current direction, results in particularly favorable behavior for negative pulses. However, various configurations between the resistor and diode are also suitable.

[0012] When the resistor is closer to the protection output than the diode, it is preferable that the anode of the diode is connected to the protection circuit input, the cathode of the diode is connected to the resistor, and the resistor is connected to the protection circuit output.

[0013] In some specific embodiments, the first capacitor has a capacitance value higher than 47nF, particularly 68nF or more, and especially 100nF or more.

[0014] These values ​​are sufficient to provide protection against electrostatic discharge.

[0015] In some specific embodiments, the second capacitor has a capacitance value of 2.2 μF or greater, and in particular, 4.7 μF or greater.

[0016] These high values ​​are intended to provide protection against dangerous pulses without requiring transient voltage suppressors, compared to known systems.

[0017] In some specific embodiments, the resistance is between 10 and 40 ohms.

[0018] In the steady-state region, a high resistance value is advantageous because it provides power sharing between the driver and the resistor. Therefore, the driver can supply a high current to the load (LED), and thus its power supply capacity is increased because the excess heat dissipation caused by the voltage rise in the power supply is shared between the resistor and the driver.

[0019] However, due to certain pulses such as a cold start, the voltage drops to 6V during the transient period, causing the system to operate at a lower voltage value from the power supply. A lower resistance value is advantageous to reduce the voltage drop across the resistor. The claimed scope results in a favorable compromise.

[0020] In some specific embodiments, the driver is a DC / DC driver.

[0021] In some specific embodiments, the driver is a linear driver.

[0022] A linear driver is a simple element that can manage the operation of a single LED.

[0023] In some specific embodiments, the light source is a solid-state light source.

[0024] The term "solid" refers to light emitted by solid-state electroluminescence that uses semiconductors to convert electricity into light. Compared with incandescent lighting, solid-state lighting generates visible light with less heat generation and less energy dissipation. The typically small mass of solid-state electronic lighting devices provides greater resistance to shock and vibration compared to fragile glass tubes / bulbs and elongated filament wires. They also eliminate filament evaporation and potentially extend the life of the lighting device. Some examples of these types of lighting include semiconductor light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), or polymer light-emitting diodes (PLEDs) as the light source, rather than an electric filament, plasma, or gas.

[0025] In some specific embodiments, the light source includes at least one RGB LED.

[0026] RGB LEDs are useful for providing various colors in a single element. These elements can also be managed by a linear driver.

[0027] The present invention is particularly suitable for powering RGB LEDs that require relatively low power compared to normal automotive lighting applications. In particular, the present invention is most suitable for interior lighting that can use RGB LEDs in accordance with color regulations existing in the field of automotive lighting that limit the color of exterior lighting of a vehicle. On the other hand, there are no such regulations for interior lighting.

[0028] Furthermore, internal lighting uses relatively low currents compared to external lighting. This means similarly low power dissipation due to the Joule effect on the resistor group placed in series within the input protection circuit, and therefore in series with the current supplying power to the driver. In high-power applications, such as some external lighting applications, such a design means high power dissipation, which can render the protection circuit inadequate in such cases.

[0029] In a further aspect of the invention, the present invention provides an automotive light-emitting device comprising an electronic assembly according to an aspect of the first invention and an optical element configured to project light emitted by a light source.

[0030] Unless otherwise defined herein, all terms used herein (including technical and scientific terms) should be construed as conventional in the art. Unless expressly defined herein, terms in general use should also be construed as conventional in the relevant art, and not as idealized or overly formal in meaning.

[0031] In this specification, the term “comprise” and its derivatives (e.g., “comprising”) should not be understood as exclusionary; that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc.

[0032] To complete the description and to provide a favorable understanding of the invention, a set of drawings is provided. These drawings form an integral part of the description and illustrate embodiments of the invention, which should not be construed as limiting the scope of the invention, but only as examples of how the invention may be carried out. The drawings include the following figures: [Brief explanation of the drawing]

[0033] [Figure 1]This diagram shows the mechanism of the electronic assembly according to the present invention. [Figure 2] This figure shows the electrical mechanism of a protective input circuit provided in a specific embodiment of the electronic configuration according to the present invention. [Figure 3] This figure shows an automobile equipped with an internal light-emitting device having such an electronic configuration. [Modes for carrying out the invention]

[0034] In these diagrams, the following reference numbers are used for each of the following elements: 1 LED 2 Input protection circuits 21 Protected Input 22 Protected Output 23 Resistors 24 diodes 25 First Capacitor 26. Second Capacitor 3 Drivers 4 Power source 10 Automotive Light-Emitting Devices 100 automobiles

[0035] The exemplary embodiments are described in sufficient detail so that those skilled in the art can embody and implement the systems and processes described herein. It is important to understand that embodiments can be provided in many alternative forms and should not be construed as being limited to the embodiments described herein.

[0036] Accordingly, the embodiments can be modified in various ways and take on various alternative forms, but specific embodiments are shown in the drawings and described in detail below as examples. There is no intention to limit the embodiments to the specific forms disclosed. Rather, all modifications, equivalents, and alternative forms included in the appended claims should be included. Elements of the exemplary embodiments are indicated by the same reference numerals consistently, where appropriate, throughout the drawings and detailed description.

[0037] Figure 1 shows the mechanism of the electronic assembly according to the present invention.

[0038] In this diagram, driver element 3 is configured to control the operation of RGB LED1.

[0039] The driver element 3 receives two inputs: a power input 31 coming from the input protection circuit 2, and a control input 32 intended to control the operation of the RGB LED 1.

[0040] Next, the input protection circuit 2 receives power from the power source 4, which comes from the vehicle's battery.

[0041] Therefore, the input protection circuit 2 is configured to eliminate all potentially dangerous pulses from the power supply so that neither the driver nor the LED receives current or voltage pulses.

[0042] As can be seen from this diagram, the input protection circuit comprises a protection input 21 that receives power and a protection output 22 that is connected to the parallel connection of the driver and the light source. Therefore, the input protection circuit 2 acts on both the LED 1 and the driver 3.

[0043] The driver is a linear driver specifically adapted to control the operation of RGB LED1.

[0044] Figure 2 shows the electrical mechanism of a protective input circuit included in a specific embodiment of the electronic configuration according to the present invention.

[0045] This diagram shows a protection input 21 that receives power and a protection output 22 that is connected to the parallel connection of the driver and LED.

[0046] Between the protection input 21 and the protection output 22, there is a group of resistors 23 and diodes 24. In this case, the resistors 23 are located after the diodes 24 for the preferred behavior of the configuration against negative pulses. However, in different embodiments, the diodes 24 may be located after the resistors 23.

[0047] The input protection circuit further comprises a first capacitor 25 and a second capacitor 26. The node between the protection input 21 and the resistor group is connected to ground via the first capacitor 25, and the node between the resistor group and the protection output 22 is connected to ground via the second capacitor 26.

[0048] The first capacitor has a capacitance value of 2.2μF, while the second capacitor has a capacitance value of 4.7μF. The resistor has a resistance value of 33Ω. These values ​​prevent dangerous pulses, and the circuit operation is fully customized to allow the driver 3 to control the operation of the RGB LED1. These values ​​are illustrative only and depend on the specifications of the automotive manufacturer and local regulations.

[0049] Figure 3 shows an automobile 100 comprising an internal light-emitting device 10 having such an electronic configuration and an optical lens for projecting light emitted by an RGB LED.

Claims

1. An electronic assembly for an automotive light-emitting device (10), wherein the electronic assembly is Light source (1), A driver (3) configured to control the operation of the light source (1), wherein the driver (3) comprises a driver power input and a driver control input, and the light source is electrically connected to the driver control input. A power supply (4) configured to supply electricity to the light source and the driver, An input protection circuit (2) is disposed between the power supply and the light source (1), wherein the input protection circuit (2) is intended to limit transient voltages and / or currents received by the light source and / or the driver, and comprises a protection input (21) and a protection output (22), Equipped with, The protection input (21), the resistance group, and the protection output (22) are connected in series, and the protection input (21), the resistance group, and the protection output (22) are connected in series. The aforementioned resistor group, The anode terminal of the diode (24) is directly connected to the protection input (21), and the resistor is connected in series between the cathode terminal of the diode (24) and the protection output (22), or The cathode terminal of the diode (24) is directly connected to the protection output (22), and the resistor is connected in series between the protection input (21) and the anode terminal of the diode (24). The node between the protection input (21) and the resistor group is connected to ground via the first capacitor (25). The node between the resistor group and the protection output (22) is connected to ground via a second capacitor (26). Electronic assembly.

2. The electronic assembly according to claim 1, wherein the input protection circuit (2) is further located between the power supply and the driver power input.

3. The electronic assembly according to claim 1, wherein the first capacitor (25) has a capacitor value higher than 47 nF, particularly 68 nF or more, and particularly 100 nF or more.

4. The electronic assembly according to claim 1, wherein the second capacitor (26) has a capacitor value of 2.2 μF or more, and in particular 4.7 μF or more.

5. The electronic assembly according to claim 1, wherein the resistor (23) is a resistance value that falls between 10 Ω and 40 Ω.

6. The electronic assembly according to claim 1, wherein the driver is a DC / DC driver.

7. The electronic assembly according to claim 1, wherein the driver is a linear driver.

8. The electronic assembly according to claim 1, wherein the light source is a solid-state light source.

9. The electronic assembly according to claim 1, wherein the light source comprises at least one RGB LED (1).

10. The electronic assembly according to claim 1, wherein the resistor is located closer to the protection output than the diode.

11. An electronic assembly according to any one of claims 1 to 10, An optical element configured to project light emitted by the aforementioned light source, An automotive light-emitting device equipped with the following features.

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