Power supply control system for light-emitting diodes

Abstract

This system (1) for controlling the power supply of light-emitting diodes (3) comprises a first set (5) of light-emitting diodes (3) and a second set (7) of light-emitting diodes (3) as well as a management unit (11) comprising a microcontroller (13) connected to a central computer (17), a power converter (15) of the sets (5; 7) of light-emitting diodes (3) connected to the microcontroller (13) by a communication bus (19), the system (1) comprising a power supply module (23) of the power converter (15) and of the microcontroller (13) as well as a switch (21) controlled by the microcontroller (13) between a first and a second power supply position respectively of the first and second sets (5; 7) of light-emitting diodes (3) by the power converter (15). Figure for the abstract: Fig. 1

Description

Title of the invention: System for controlling the power supply of light-emitting diodes Technical field

[0001] The present invention relates to systems for managing the electrical power supply of light sources, in particular for motor vehicles.

[0002] In particular, the present invention relates to the management of the electrical power supply of sets of light-emitting diodes, also called LEDs or LEDs, which participate in the realization of several lighting functions of a motor vehicle, in particular the function of indicator light, position light, and daytime running light, also called DRL (daytime running light in English terms).

[0003] More generally, the present invention applies to any device comprising light-emitting diodes. Previous techniques

[0004] On the front of a motor vehicle, namely on the side of the vehicle facing the road when said vehicle is moving forward, there are two flashing lights, one on the right and the other on the left, making it possible to signal to other users the direction that the vehicle is about to take.

[0005] The turn signals are generally integrated into a headlight which also includes lights having functions of dipped beam, main beam, daytime running lights, and position lights.

[0006] Alternatively, another projector, called FCL for “front combi light” in Anglo-Saxon terms, specifically includes an indicator light, a daytime running light and a position light.

[0007] Most of the time, the flashing light comprises a set of light-emitting diodes having a driver specific to said flashing light, also called a management unit. Another driver is then used for a second set of light-emitting diodes, forming for example the position light. Indeed, the design of the headlights being specific to each vehicle model, it is customary for each driver to be independent and specific, which has the consequence of complicating the control electronics. Statement of the invention

[0008] The present invention therefore aims to overcome the aforementioned drawbacks and to provide an electronic system for controlling sets of light-emitting diodes which is simple and capable of independently managing several different sets of light-emitting diodes. The system is furthermore configurable to adapt to different vehicle models.

[0009] The present invention relates to a system for controlling the power supply of light-emitting diodes, comprising a first set of light-emitting diodes and a second set of light-emitting diodes, the system further comprising a management unit comprising a microcontroller connected to a central computer, a power converter for the sets of light-emitting diodes connected to the microcontroller, for example by a communication bus, the system comprising a power supply module for the power converter and the microcontroller as well as a switch controlled by the microcontroller between a first and a second power supply position respectively of the first and second sets of light-emitting diodes by the power converter.

[0010] Thus, two sets of light-emitting diodes can be controlled by the same management unit, the first set being able to form a flashing light and the second set a position light or daytime running light. The power converter as well as the microcontroller can also be configured differently depending on the motor vehicle models in order to adapt to each one.

[0011] Advantageously, the system comprises a means for measuring voltage across a defined number of diodes of the first set of light-emitting diodes, said voltage measuring means communicating with the microcontroller.

[0012] In a particular embodiment, the system further comprises a dummy load controlled by the microcontroller and configured to consume a current greater than a predetermined current value, preferably 100 mA, when the microcontroller does not detect any fault in the power converter or in the sets of light-emitting diodes, and configured to consume a current less than a predetermined current value, preferably 1 mA, when the microcontroller detects a fault in the power converter or in the sets of light-emitting diodes.

[0013] Advantageously, the microcontroller is configured to detect a fault in the power converter or in the sets of light-emitting diodes by measuring current or voltage at the terminals, preferably the output terminals, of the power converter.

[0014] Advantageously, the switch is a reversing switch and comprises at least one transistor and / or at least one relay.

[0015] Advantageously, the management unit comprises at least two power converters, preferably at least three power converters.

[0016] In another embodiment, at least two power converters of the light-emitting diodes are connected in parallel and supply power to the first or second set of light-emitting diodes via the switch.

[0017] In a particular embodiment, the system comprises at least a third set of light-emitting diodes powered via at least one power converter different from the power converter(s) powering the first or second set of light-emitting diodes via the switch.

[0018] Advantageously, the system comprises a single temperature sensor configured to measure the temperature of the first set of light-emitting diodes and the second set of light-emitting diodes.

[0019] The present invention also relates to a motor vehicle comprising a as defined above, in which the first set of light-emitting diodes forms a flashing light, and in which the second set of light-emitting diodes forms a position light and / or daytime running light. Brief description of the drawings

[0020] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

[0021] [Fig.l] is a schematic view of a first embodiment of a system for controlling the power supply of light-emitting diodes according to the invention;

[0022] [Fig.2] is a schematic view of a second embodiment of a system for controlling the power supply of light-emitting diodes according to the invention;

[0023] [Fig.3] is a schematic view of a third embodiment of a system for controlling the power supply of light-emitting diodes according to the invention; and

[0024] [Fig.4] is a schematic view of a fourth embodiment of a system for controlling the power supply of light-emitting diodes according to the invention. Detailed description of at least one embodiment

[0025] [Fig.l] schematically shows an embodiment of a system 1 for controlling the power supply of light-emitting diodes 3 according to the invention.

[0026] The system 1 comprises a first set 5 of light-emitting diodes 3 and a second set 7 of light-emitting diodes 3.

[0027] The system 1 is for example installed on board a motor vehicle 9. In this embodiment, the first set 5 of light-emitting diodes 3 forms for example a flashing light, for example orange in color, and the second set 7 of light-emitting diodes 3 forms for example a position light and / or daytime running light, in white color.

[0028] In a particular embodiment, the first set 5 of light-emitting diodes 3 and the second set 7 of light-emitting diodes 3 are combined on the same optical system.

[0029] The system 1 further comprises a management unit 11 comprising a microcontroller 13 and a power converter 15 of the sets 5 and 7 of light-emitting diodes 3.

[0030] The power converter 15 is preferably a buck converter, or a series chopper.

[0031] The microcontroller 13 is connected to a central computer 17, for example a central computer 17 of the motor vehicle 9. In a particular embodiment, the motor vehicle 9 comprises said central computer 17 receiving instructions from the dashboard and from the controls close to the driver's steering wheel. The instructions are for example instructions to switch on a flashing light to indicate to other road users that the vehicle is going to deviate from its current trajectory. The central computer 17 thus communicates these instructions to the microcontroller 13.

[0032] The power converter 15 is connected to the microcontroller 13 by a communication bus 19 transmitting instructions on how a set 5 or 7 of light-emitting diodes 3 must be lit, for example continuously or flashing.

[0033] The current supplied by the power converter 15 to the sets 5 or 7 of light-emitting diodes 3 can be adjusted by resistors paired with the light-emitting diodes 3 and read back by the microcontroller 13 which delivers, depending on the value of each resistor, a particular current to be injected into the light-emitting diodes 3.

[0034] The control system 1 further comprises a switch 21 controlled by the microcontroller 13 between a first and a second power supply position respectively of the first 5 and of the second set 7 of light-emitting diodes 3 by the power converter 15.

[0035] Advantageously, the switch 21 is a reversing switch and comprises at least one transistor and / or at least one relay.

[0036] Thus, the power converter 15 is connected to one or the other set 5 or 7 of light-emitting diodes 3 via the switch 21. This makes it possible to share the management unit 11, in particular the microcontroller 13 and the power converter 15, for two separate sets 5 and 7 of light-emitting diodes 3, which may have different functions.

[0037] Furthermore, the control system 1 comprises a module 23 for supplying the power converter 15 and the microcontroller 13, as well as a ground connection 25.

[0038] The sets 5 and 7 of light-emitting diodes 3 are powered via the power converter 15.

[0039] Advantageously, the system 1 comprises a means 27 for measuring the voltage across a defined number of diodes 3 of the first set of light-emitting diodes 5, said voltage measuring means 27 communicating with the microcontroller 13.

[0040] The voltage measuring means 27, for example a voltmeter integrated into the microcontroller 13, measures for example the voltage between the ground 25 and two light-emitting diodes 3, preferably the two light-emitting diodes connected to the ground 25, in other words the ones closest to the ground connection 25.

[0041] The voltage measuring means 27 thus makes it possible to check the lighting of the first set 5 of light-emitting diodes 3, and in particular makes it possible to ensure that the correct set of light-emitting diodes 3 is lit.

[0042] If the current flows correctly in the first set 5 of light-emitting diodes 3, a voltage greater than a predetermined threshold, for example between 2V and 6V, is detected and proves the correct operation of the first set 5 of light-emitting diodes 3, in other words the indicators.

[0043] The voltage measuring means 27 therefore makes it possible to form a safety device capable of carrying out a diagnosis of the correct operation of the switch 21.

[0044] Optionally, the system 1 further comprises a dummy load 29 controlled by the microcontroller 13 and configured to consume a current greater than a predetermined current value, preferably 100 mA, when the microcontroller 13 does not detect any fault in the power converter 15 or in the sets 5 and 7 of light-emitting diodes 3.

[0045] The dummy load is also connected to the central computer.

[0046] The dummy load 29 is also configured to consume a current less than a predetermined current value, preferably 1 mA, when the microcontroller 13 detects a fault in the power converter 15 or in the sets 5 and 7 of light-emitting diodes.

[0047] A fault is for example a short circuit, a defective or short-circuited light-emitting diode 3. The fault is for example detected by the microcontroller 13 via a means for measuring voltage and / or current at the terminals of the power converter 15.

[0048] The dummy load 29 is particularly interesting for a motor vehicle 9 which passes from an architecture where the light-emitting diodes were powered and controlled directly by the central computer 17 or a dedicated management unit, with an architecture as described previously.

[0049] Indeed, the presence of the dummy load 29 makes it possible to send a signal to the central computer 17 indicating that the light-emitting diodes 3 are lit, a signal which was previously directly received by the central computer, the latter powering said light-emitting diodes. In other words, the dummy load 29 is a decoy intended to indicate to the central computer 17 the correct operating state of the light-emitting diodes 3.

[0050] Thus, when the indicator formed by the first assembly 5 is activated and there is no fault, the dummy load 29 is activated and consumes sufficient current for the central computer to believe that it is powering said first assembly 5. If the microcontroller detects a fault, then it relaxes the dummy load and the central computer sees the fault, due to a lack of current, and can thus switch to a degraded mode, for example by warning the driver by doubling the flashing frequency of the operating indicators on the dashboard and by doubling the flashing frequency of the indicators installed on the side and at the rear of the vehicle. Advantageously, the system comprises a single temperature sensor 31 configured to measure the temperature of the first assembly 5 of light-emitting diodes 3 and of the second assembly 7 of light-emitting diodes 3.

[0051] The sensor 31 communicates for example with the microcontroller 13.

[0052] Thus, the thermal management of the system is simplified since a single temperature sensor 31 is sufficient to measure the two sets 5 and 7 of light-emitting diodes 3.

[0053] Generally speaking, thanks to this control system 1, it is not necessary to develop and install specific control electronics for a flashing light of a motor vehicle. It is sufficient to wire the sets of light-emitting diodes to the management unit 11.

[0054] This system 1 therefore allows an economic gain, since the system can become universal, only the wiring having to be adapted to the shape of the location of the flashing light and the position light in the headlight or in the FCL.

[0055] [Fig.2] shows another embodiment of a system 1 according to the invention.

[0056] In this embodiment, system 1 includes the same features as system 1 of [Fig.l], including optional features that remain optional.

[0057] In this embodiment, the management unit 11 comprises at least two power converters 15.

[0058] In this embodiment, the at least two power converters 15 of the light-emitting diodes 3 are connected in parallel and supply the first or second set 5 and 7 of light-emitting diodes 3 via the switch 21.

[0059] Obviously, an additional number of power converters 15 can be added in parallel with the power converters already illustrated in [Fig.2], so as to increase the power available for the sets 5 and 7 of light-emitting diodes.

[0060] [Fig.3] shows a third embodiment of a system 1 according to the invention.

[0061] In this embodiment, system 1 includes the same features as system 1 of [Fig.l], including optional features that remain optional.

[0062] In this embodiment, the system 1 comprises a third set 33 of light-emitting diodes, forming for example a position or daytime running light, or a portion of a position or daytime running light, or a flashing light.

[0063] This third assembly 33 is controlled and powered via a specific power converter 15.

[0064] Obviously, other sets of light-emitting diodes 3 and other power converters 15 can be added in this embodiment.

[0065] [Fig. 4] shows a fourth embodiment of a system 1 according to the invention. This embodiment is a combination of the embodiments illustrated in Figures 2 and 3.

[0066] In this embodiment, system 1 includes the same features as system 1 of [Fig.l], including optional features that remain optional.

[0067] Advantageously, the management unit 11 comprises at least two power converters 15 connected in parallel and supplying the first or second set 5 and 7 of light-emitting diodes 3 via the switch 21.

[0068] In addition, the system 1 comprises a third set 33 of light-emitting diodes forming, for example, a position light or daytime running light, or a portion of a position light or daytime running light, or a flashing light.

[0069] This third assembly 33 is controlled and powered via a specific power converter 15.

[0070] Obviously, other sets of light-emitting diodes 3 and other power converters 15 can be added in this embodiment.

Claims

Claims

1. System (1) for controlling the power supply of light-emitting diodes (3), comprising a first set (5) of light-emitting diodes (3) and a second set (7) of light-emitting diodes (3), characterized in that it comprises a management unit (11) comprising a microcontroller (13) connected to a central computer (17), a power converter (15) of the sets (5; 7) of light-emitting diodes (3) connected to the microcontroller (13) by a communication bus (19), the system (1) comprising a power supply module (23) of the power converter (15) and of the microcontroller (13) as well as a switch (21) controlled by the microcontroller (13) between a first and a second power supply position respectively of the first and second sets (5; 7) of light-emitting diodes (3) by the power converter (15).

2. System (1) according to claim 1, comprising means (27) for measuring voltage across a defined number of diodes (3) of the first set (5) of light-emitting diodes (3), said voltage measuring means (27) communicating with the microcontroller (13).

3. System (1) according to one of claims 1 and 2, further comprising a dummy load (29) controlled by the microcontroller (13) and configured to consume a current greater than a predetermined current value, preferably 100 mA, when the microcontroller (13) does not detect any failure in the power converter (15) or in the sets (5; 7; 33) of light-emitting diodes (3), and configured to consume a current less than a predetermined current value, preferably 1 mA, when the microcontroller (13) detects a failure in the power converter (15) or in the sets (5; 7; 33) of light-emitting diodes (3).

4. System (1) according to claim 3, wherein the microcontroller (13) is configured to detect a fault in the power converter (15) or in the sets (5; 7; 33) of light-emitting diodes (3) by measuring current or voltage at the terminals of the power converter (15).

5. System (1) according to any one of claims 1 to 4, wherein the switch (21) is a reversing switch and comprises at least one transistor and / or at least one relay.

6. System (1) according to any one of claims 1 to 5, wherein the management unit (11) comprises at least two power converters (15), preferably at least three power converters (15).

7. System (1) according to claim 6, wherein at least two power converters (15) of the light-emitting diodes (3) are connected in parallel and supply the first or second set (5; 7) of light-emitting diodes (3) via the switch (21).

8. System (1) according to one of claims 6 and 7, comprising at least one third set (33) of light-emitting diodes (3) powered via at least one power converter (15) different from the power converter(s) (15) powering the first or second set (5; 7) of light-emitting diodes (3) via the switch (21).

9. System (1) according to any one of claims 1 to 8, comprising a single temperature sensor (31) configured to measure the temperature of the first set (5) of light-emitting diodes (3) and of the second set (7) of light-emitting diodes (3).

10. Motor vehicle (9) comprising a system (1) according to any one of claims 1 to 9, in which the first set (5) of light-emitting diodes (3) forms a flashing light, and in which the second set (7) of light-emitting diodes (3) forms a position light and / or daytime running light.

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