Method for configuring a lamp for a vehicle and configured lamp for a vehicle

Abstract

The invention relates to a method for configuring a light (1) for a vehicle (1), wherein the light (1) comprises a light module (2) including a number of light sources (2a), in particular LEDs, and a driver circuit (3) for supplying electrical power to the light module (2), wherein the number of light sources (2a) are arranged in a light string (2b), wherein the light module (2) has at least one electronic auxiliary component (Rh) in the form of an ohmic resistor, which auxiliary component (Rh) is provided to be energized during normal operation of the light module (2), wherein this electronic auxiliary component (Rh) has a resistance value that is representative of the brightness class of the light module (2), wherein the method comprises the following steps: a) providing a light module (2) and a suitable driver circuit (3), b) determining the resistance value of the auxiliary component (Rh) of the light module (2),c) Configure the driver circuit (3) depending on the resistance value detected in step b) so that the output voltage or output current of the driver circuit (3) is adjusted according to the brightness class of the light sources (2a).

Description

[0001] The invention relates to a method for configuring a light for a vehicle, wherein the light comprises a lighting module including a number of light sources, in particular LEDs, and a driver circuit for supplying electrical power to the lighting module, wherein the number of light sources are arranged in a lighting string.

[0002] Headlights and taillights typically use simple LED PCBs powered by lighting control units or control boards. Due to varying light source brightness classes, a binning resistor is usually integrated onto the LED PCB or a lighting module to identify the specific brightness class.

[0003] The invention aims to create a solution that enables the brightness class to be recognized and also reduces the required cabling and electronics effort.

[0004] This problem is solved by a method of the type mentioned at the outset, in which, according to the invention, the lighting module has at least one electronic auxiliary component in the form of an ohmic resistor, which auxiliary component is provided to be energized during normal operation of the lighting module, wherein this electronic auxiliary component has a resistance value that is representative of the brightness class of the lighting module, in particular of the light sources of the lighting module, wherein the method comprises the following steps: a) providing a lighting module and a suitable driver circuit, b) detecting the resistance value of the auxiliary component of the lighting module, c) configuring the driver circuit as a function of the resistance value detected in step b), so that the output voltage or output current of the driver circuit is adjusted according to the brightness class of the light sources.

[0005] The number of light sources is typically two or more per string. Multiple strings may also be used. However, it is also conceivable that only a single light source per string and / or only a single string is used. "Normal operation" of a light source is defined as operation in which the light source emits light and the current is typically within the light source's rated range. Tables may be provided for the resistance values ​​of the auxiliary components of the lighting modules, in which the resistance values ​​are assigned to different brightness classes, particularly a bijective assignment. The driver circuit can then be configured by comparing the values ​​to the table, thus determining the current brightness class. Each brightness class will typically be assigned its own specific resistance value.

[0006] In particular, it may be provided that in or after step b) or c) the driver circuit is connected to the lighting module for the electrical supply of the lighting module.

[0007] Furthermore, it may be planned that step c) takes place during the manufacturing of the luminaire or the initial commissioning of the luminaire. For this purpose, as long as the driver circuit has not yet been configured according to the brightness class, a protective operation with low output power can be assumed in order to then – after successful detection – perform the configuration and switch to normal operation.

[0008] Alternatively, the measuring current can also be higher than the nominal current.

[0009] In particular, it may be possible to perform steps b) and c) only once during the manufacturing or initial commissioning of the luminaire, and to permanently retain the configuration of the lighting module thereafter. This allows for a faster system startup once the configuration has been established. For this purpose, the configuration can be stored in memory.

[0010] Furthermore, the driver circuit may include a microcontroller to which the resistance value detected in step b) is supplied, and the microcontroller is configured to control the output voltage / current of the driver circuit depending on the detected brightness class. Unlike in the prior art, the microcontroller does not detect the resistance value itself, but rather this resistance value is supplied to the microcontroller.

[0011] In particular, the driver circuit can be configured to include a constant voltage converter and a linear regulator, with the linear regulator serving to regulate the current in the lighting circuit. The auxiliary component is connected in series with the lighting circuit. The linear regulator does not regulate the output voltage, but rather the current in the lighting circuit. That is, the linear regulator acts as a constant current sink in the lighting circuit, and the available voltage is determined by the constant voltage converter.

[0012] Furthermore, the auxiliary component may be provided with a resistance value selected such that, during normal operation of the lighting module, the electrical power dissipated by the auxiliary component is less than 10% of the power of the lighting string, wherein the resistance value of the auxiliary component is preferably between 0.1 ohms and 5 ohms, and particularly between 0.5 ohms and 1.5 ohms. Typical currents through the light sources, especially in the form of LEDs, are ≤ 100 mA.

[0013] In particular, it can be provided that the resistance value of the auxiliary component of the lighting module according to step b) is determined during the manufacture of the luminaire by establishing an electrical connection between the lighting module and the driver circuit, temporarily short-circuiting the lighting string, preferably using a needle adapter, and driving a constant current through the auxiliary component by means of the driver circuit, whereby its resistance value and thus the brightness class of the light sources in the lighting string can be deduced by simultaneously measuring the voltage at the auxiliary component.

[0014] Furthermore, it may be provided that the auxiliary component is connected in parallel to the lighting string in order to dissipate more quickly any electrical voltage that may still be temporarily present on the lighting string despite a desired switch-off of the driver circuit due to capacitive effects.

[0015] In particular, it can be provided that the driver circuit has at least two channels, wherein the auxiliary component is led from a first node common to the light string to a first channel, and wherein the light string is led from the first node to a second channel, wherein a second node is provided on the first channel, wherein an additional electronic component in the form of an ohmic resistor, hereinafter referred to as the additional resistor, is provided between the second node and the second channel, such that in the case of high-impedance operation of the first channel there is essentially a series circuit between the auxiliary component and the additional resistor, and this series circuit is connected in parallel to the light string.

[0016] Furthermore, it may be provided that the resistance value of the additional resistor is between 10 kOhm and 30 kOhm and the resistance value of the auxiliary component is between 1 and 5 Ohm.

[0017] In particular, it can be provided that the resistance value of the auxiliary component of the lighting module is determined according to step b) by activating the first channel and passing a reference current through the auxiliary component and the additional resistor to the second channel, whereby the differential voltage between the two channels and the potential at the first node are detected, and the resistance value of the auxiliary component is deduced by measuring quantities derived from these. This is particularly important when the light is used as a rear light.

[0018] Furthermore, it can be provided that the first channel is operated at high impedance during normal operation of the luminaire. This means that the channel is switched at high impedance to keep incoming currents low and thus minimize electrical losses.

[0019] In particular, it can be provided that the luminaire comprises two or more strands, each having light sources, wherein the light sources of the strands have the same brightness class, wherein each strand is assigned its own channel, wherein the detection of the brightness class is carried out using a method according to the invention.

[0020] The invention further relates to a configured luminaire, wherein the luminaire comprises a lighting module including a number of light sources, in particular LEDs, and a driver circuit for supplying electrical power to the lighting module, wherein the number of light sources are arranged in a lighting string, wherein the lighting module has at least one electronic auxiliary component in the form of an ohmic resistor, which auxiliary component is provided to be energized in normal operation of the lighting module, wherein this electronic auxiliary component has a resistance value that is representative of the brightness class of the lighting module, in particular of the light sources of the lighting module, wherein the configuration of the luminaire was obtained by applying a method according to the invention.

[0021] The invention is explained in more detail below with reference to an exemplary and non-limiting embodiment, which is illustrated in the figures. These show Figure 1 a state-of-the-art equivalent circuit diagram of a luminaire, Figure 2 an equivalent circuit diagram of a luminaire according to the invention in a first embodiment, Figure 3 an equivalent circuit diagram of a luminaire according to the invention in a second embodiment, Figure 4 an equivalent circuit diagram of a luminaire according to the invention analogous to Fig. 3 , however, with two light strings of the same brightness class, Figure 5 an equivalent circuit diagram of a luminaire according to the invention analogous to Fig. 3 , however, with two light strings of different brightness classes, and Figure 6 An equivalent circuit diagram of a typical driver circuit for supplying power to a lighting string.

[0022] In the following figures, unless otherwise stated, the same reference symbols denote the same features.

[0023] Figure 1 Figure 1 shows an equivalent circuit diagram of a luminaire 1 according to the state of the art. An individual resistance value Rh is located on a lighting module 2 in the form of an LED PCB. This individual resistance value Rh represents the brightness class of the installed LEDs. A microcontroller 3a on the control board or driver circuit 3 reads the voltage value, which results from Rp and Rh, at an ADC pin and sets the current according to a table stored in the microcontroller 3a. The auxiliary resistor Rh is not energized during normal operation and is therefore only intended for classifying the brightness class. To prevent, for example, unwanted glowing, an additional resistor must be provided.

[0024] With regard to Fig. 2A first embodiment of the invention, which has many similarities with the remaining embodiments, will now be discussed. All embodiments of the invention have in common that they provide a method for configuring a light 1 for a vehicle, wherein the light 1 comprises a lighting module 2 including a number of light sources 2a, in particular LEDs, and a driver circuit 3 for supplying electrical power to the lighting module 2. The light sources 2a are arranged in at least one lighting string 2b.Unlike the prior art, the lighting module 2 has at least one electronic auxiliary component Rh in the form of an ohmic resistor, which auxiliary component Rh is intended to be energized even during normal operation of the lighting module 2, wherein this electronic auxiliary component Rh has a resistance value that is representative of the brightness class of the lighting module 2, in particular of the light sources of the lighting module, wherein the method comprises the following steps: a) providing a lighting module 2 and a suitable driver circuit 3, b) determining the resistance value of the auxiliary component Rh of the lighting module 2, and c) configuring the driver circuit 3 depending on the resistance value determined in step b, such that the output voltage or output current of the driver circuit 3 is adjusted according to the brightness class of the light sources 2a.The driver circuit includes a DC / DC converter 5, which is powered by the supply voltage Uv. Reference numeral 7 refers to a communication bus, e.g., SPI or UART.

[0025] In particular, it may be provided that in or after step b) or c), the driver circuit 3 is connected to the lighting module 2 to supply the lighting module 2 with electricity. Step c) can, for example, be performed during the manufacturing of the luminaire 1 or during its initial commissioning. Specifically, it may be provided that steps b) and c) are performed only once during the manufacturing or initial commissioning of the luminaire 1 and that the configuration of the lighting module 2 is subsequently retained permanently. This allows for a rapid "start-up" of the luminaire 1 once the configuration has been established. For this purpose, the luminaire 1 can have a memory in which the configuration is stored.

[0026] Furthermore, it may be provided that the driver circuit 3 has a microcontroller 3a to which the resistance value detected in step b) is supplied, wherein the microcontroller 3a is configured to control the output voltage / output current of the driver circuit 3 depending on the detected brightness class.

[0027] With regard to Fig. 2It should be noted that the driver circuit 3 may, in particular, include a constant voltage converter and a linear regulator, the linear regulator being used to regulate the current in the lighting string 2b, with the auxiliary component Rh being connected in series with the lighting string 2b. The auxiliary component Rh may be configured to have a resistance value such that, during normal operation of the lighting module 2, the electrical power dissipated by the auxiliary component Rh is less than 10% of the power of the lighting string 2b, with the resistance value of the auxiliary component Rh preferably being between 0.1 ohms and 5 ohms, and particularly between 0.5 ohms and 1.5 ohms.Furthermore, it can be provided that the resistance value of the auxiliary component Rh of the lighting module 2 according to step b) is determined during the manufacture of the luminaire 1 by establishing an electrical connection between the lighting module 2 and the driver circuit 3, temporarily short-circuiting the lighting string 2b, preferably using a needle adapter 4, and driving a constant current through the auxiliary component Rh by means of the driver circuit 3, whereby the resistance value of the auxiliary component Rh and thus the brightness class of the light sources 2a in the lighting string 2b can be deduced by simultaneously measuring the voltage at the auxiliary component Rh.

[0028] With regard to Fig. 3 It should be mentioned that, as an alternative to Fig. 2The auxiliary component Rh can be connected in parallel to the lighting string 2b in order to dissipate more quickly any electrical voltage that may still be temporarily present on the lighting string 2b due to capacitive effects, even after the driver circuit 3 has been switched off. This reduces any unwanted afterglow of the light sources 2a.

[0029] Furthermore, it can be provided that the driver circuit 3 has at least two channels CH1, CH2, wherein the auxiliary component Rh is led from a first node K1 common with the light string 2b to a first channel CH1, and wherein the light string 2b is led from the first node K1 to a second channel CH2, wherein a second node K2 is provided at the first channel CH1, wherein an additional electronic component in the form of an ohmic resistor is provided between the second node K2 and the second channel CH2, hereinafter referred to as additional resistor Rh+, so that in a high-impedance operation of the first channel CH1 there is essentially a series circuit between the auxiliary component Rh and the additional resistor Rh+, and this series circuit is connected in parallel to the light string 2b.When Rh+ is used as an anti-glow resistor, it can additionally dissipate energy from residual capacitances or leakage currents during operation, which would otherwise lead to unwanted afterglow. Preferably, the resistance value of the additional resistor Rh+ is between 10 kΩ and 30 kΩ, and the resistance value of the auxiliary component Rh is between 1 and 5 Ω.

[0030] In particular, it can be provided that the resistance value of the auxiliary component Rh of the lighting module 2 is determined according to step b) by activating the first channel CH1 and passing a reference current through the auxiliary component Rh and the additional resistor Rh+ to the second channel CH2, whereby the differential voltage Uch12 between the two channels CH1 and CH2, as well as the potential at the first node K1, are measured, and the resistance value of the auxiliary component Rh is deduced by measuring quantities derived from these measurements. The potential measurement can, for example, be performed with respect to CH2. To save energy, it can be provided that the first channel CH1 is operated at a high impedance during normal operation of the luminaire 1.

[0031] With regard to Figure 4 and 5It should be mentioned that it can also be provided that the luminaire 1 comprises two or more strands 2b, each having light sources 2a, wherein the light sources 2a of the strands 2b have the same brightness class, wherein each strand 2b is assigned its own channel CH-4, CH-2, wherein the detection of the brightness class is carried out using a method according to the invention.

[0032] In Figure 4 Do the light strings 2b or their light sources 2a have the same brightness class? Figure 5 However, different brightness classes are present, which is why different auxiliary resistors Rh1 and Rh2 are provided.

[0033] Figure 6 Figure 2 shows an equivalent circuit diagram of a typical DC-DC converter for supplying a lighting module 2. Reference symbol 5a denotes a boost converter and reference symbol 5b a buck converter.

[0034] The invention further relates to a configured luminaire 1, wherein the luminaire 1 comprises a luminaire module 2 including a number of light sources 2a, in particular LEDs, and a driver circuit 3 for supplying electrical power to the luminaire module 2, wherein the number of light sources 2a are arranged in a luminaire string 2b, wherein the luminaire module 2 has at least one electronic auxiliary component Rh in the form of an ohmic resistor, which auxiliary component Rh is provided to be energized in normal operation of the luminaire module 2, wherein this electronic auxiliary component Rh has a resistance value that is representative of the brightness class of the luminaire module 2, in particular of the light sources of the luminaire module, wherein the configuration of the luminaire 1 was obtained by applying a method according to the invention.

[0035] The invention is not limited to the embodiments shown, but is defined by the entire scope of protection of the claims. Individual aspects of the invention or the embodiments can also be adopted and combined. In particular, all features of the method can be implemented in the device, or those features of the method that are reflected in the implementation of the device can also be part of the device. Any reference numerals in the claims are exemplary and serve only to improve the readability of the claims, without limiting them.

Claims

1. A method for configuring a luminaire (1) for a vehicle, wherein the luminaire (1) comprises a luminaire module (2) including a number of light sources (2a), in particular LEDs, and a driver circuit (3) for supplying electrical power to the luminaire module (2), wherein the number of light sources (2a) are arranged in a luminaire string (2b), wherein the luminaire module (2) comprises at least one electronic auxiliary component (Rh) in the form of an ohmic resistor, which auxiliary component (Rh) is provided to be energized during normal operation of the luminaire module (2), wherein this electronic auxiliary component (Rh) has a resistance value that is representative of the brightness class of the luminaire module (2), in particular of the light sources of the luminaire module, wherein the method comprises the following steps: a) providing a luminaire module (2) and a suitable driver circuit (3), b) determining the resistance value of the auxiliary component (Rh) of the luminaire module (2),c) Configure the driver circuit (3) depending on the resistance value detected in step b) so that the output voltage or output current of the driver circuit (3) is adjusted according to the brightness class of the light sources (2a).

2. Method according to claim 1, wherein in or after step b) or c) the driver circuit (3) is connected to the light module (2) for the electrical supply of the light module (2).

3. Method according to claim 1 or 2, wherein step c) is carried out during the manufacture of the lamp (1) or the first commissioning of the lamp (1).

4. Method according to claim 3, wherein steps b) and c) are performed only once during the manufacture or initial commissioning of the luminaire (1) and the configuration of the luminaire module (2) is subsequently maintained permanently.

5. Method according to one of the preceding claims, wherein the driver circuit (3) comprises a microcontroller (3a) to which the resistance value detected in step b) is supplied, wherein the microcontroller (3a) is configured to control the output voltage / output current of the driver circuit (3) depending on the detected brightness class.

6. Method according to one of the preceding claims, wherein the driver circuit (3) comprises a constant voltage converter and a linear regulator, wherein the linear regulator is provided for adjusting the current in the lighting string (2b), wherein the auxiliary component (Rh) is connected in series with the lighting string (2b).

7. Method according to claim 6, wherein the auxiliary component (Rh) has a resistance value selected such that in normal operation of the lighting module (2) the electrical power dissipated at the auxiliary component (Rh) is less than 10% of the power of the lighting string (2b), wherein the resistance value of the auxiliary component (Rh) is preferably between 0.1 ohms and 5 ohms, in particular between 0.5 ohms and 1.5 ohms.

8. Method according to claim 6 or 7, wherein the detection of the resistance value of the auxiliary component (Rh) of the light module (2) according to step b) during the manufacture of the light (1) is carried out by establishing an electrical connection between the light module (2) and the driver circuit (3), temporarily short-circuiting the light string (2b), preferably using a needle adapter (4), and driving a constant current through the auxiliary component (Rh) by means of the driver circuit (3), wherein the resistance value and thus the brightness class of the light sources (2a) in the light string (2b) is determined by simultaneously measuring the voltage at the auxiliary component (Rh).

9. Method according to one of claims 1 to 5, wherein the auxiliary component (Rh) is connected in parallel to the light string (2b) in order to reduce more quickly an electrical voltage which may still be temporarily present on the light string (2b) despite a desired switching off of the driver circuit (3) due to capacitive effects.

10. Method according to any one of claims 1 to 5, wherein the driver circuit (3) has at least two channels (CH1, CH2), wherein the auxiliary component (Rh) is led from a first node (K1) common with the light string (2b) to a first channel (CH1), and wherein the light string (2b) is led from the first node (K1) to a second channel (CH2), wherein a second node (K2) is provided at the first channel (CH1), wherein an additional electronic component in the form of an ohmic resistor, hereinafter referred to as the additional resistor (Rh+), is provided between the second node (K2) and the second channel (CH2), such that in the case of high-impedance operation of the first channel (CH1) there is essentially a series circuit between the auxiliary component (Rh) and the additional resistor (Rh+), and this series circuit is connected in parallel to the light string (2b).

11. Method according to claim 10, wherein the resistance value of the additional resistor (Rh+) is between 10 kOhm and 30 kOhm and the resistance value of the auxiliary component (Rh) is between 1 and 5 Ohm.

12. Method according to claim 10 or 11, wherein the detection of the resistance value of the auxiliary component (Rh) of the light module (2) according to step b) is carried out by activating the first channel (CH1) and passing a reference current through the auxiliary component (Rh) and the additional resistor (Rh+) to the second channel (CH2), wherein the differential voltage (Uch12) between the two channels (CH1, CH2) and the potential at the first node (K1) are detected and the resistance value of the auxiliary component (Rh) is deduced by measuring quantities derived therefrom.

13. Method according to one of claims 10 to 12, wherein the first channel (CH1) is operated at high impedance during normal operation of the luminaire (1).

14. Method according to one of the preceding claims, wherein the luminaire (1) comprises two or more strands (2b) each having light sources (2a), wherein the light sources (2a) of the strands (2b) have the same brightness class, wherein each strand (2b) is assigned its own channel (CH-4, CH-2), wherein the detection of the brightness class is carried out using a method according to one of the preceding claims.

15. Configured luminaire (1), wherein the luminaire (1) comprises a luminaire module (2) comprising a number of light sources (2a), in particular LEDs, and a driver circuit (3) for supplying electrical power to the luminaire module (2), wherein the number of light sources (2a) are arranged in a luminaire string (2b), wherein the luminaire module (2) comprises at least one electronic auxiliary component (Rh) in the form of an ohmic resistor, which auxiliary component (Rh) is provided to be energized during normal operation of the luminaire module (2), wherein this electronic auxiliary component (Rh) has a resistance value that is representative of the brightness class of the luminaire module (2), in particular of the light sources of the luminaire module, wherein the configuration of the luminaire (1) was obtained by applying a method according to one of the preceding claims.

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