Method and system for setting a driving current of a luminaire

Abstract

The present invention relates to the incorporation of a current limit / regulation circuit on a luminaire board for ensuring that the luminaire board will automatically operate at its desired current after replacement. Due to the initial mismatch between the driver's current supply and the luminaire board's demand caused by the current control at the luminaire board, the driver output voltage will drift towards the driver's maximum output voltage. When the maximum output voltage is reached, the driver is configured to operate in constant voltage (CV) mode, sensing the output current and reducing its output current to the same value as the current consumed by the current controlled luminaire board. Alternatively, the driver can gradually reduce the setpoint of the output current until it just leaves the CV mode and stays at that setpoint. In this way, the driver will automatically operate at the correct current for the newly installed luminaire board without any action from the user.

Description

Technical Field

[0001] This invention relates to the field of lighting systems, such as, but not limited to, solid-state lighting systems, for a variety of different applications in homes, offices, retail, hotels, and industries. Background Technology

[0002] Throughout this disclosure, luminaires should be understood as any type of lighting unit or lighting apparatus, including one or more light sources (including visible or invisible (infrared (IR) or ultraviolet (UV)) light sources) for lighting and / or communication purposes, and optionally other internal and / or external components necessary for proper operation of the lighting, such as those for distributing light, positioning and protecting the light source and ballast (where applicable), and connecting the luminaire to a power source. Luminaires can be of conventional types, such as recessed or surface-mounted incandescent lamps, fluorescent lamps, or other discharge lamps. Luminaires can also be of non-conventional types, such as optical fibers having a light source and a fiber core or "light tube" for guiding the light produced by the light source.

[0003] To reduce waste and achieve a circular economy, future lighting fixtures need to be designed to be serviceable. During servicing or upgrade operations, lighting modules (e.g., LED modules also known as "L2 (Level 2) boards") frequently need to be replaced. These modules can serve as a carrier for multiple light sources (e.g., multiple LEDs) and can be manufactured as printed circuit boards (PCBs) from conventional PCB materials (such as FR4), bent on a rigid or MCPCB (metal core PCB) carrier to enhance cooling. After years of use, the old components may become obsolete and no longer usable. When a damaged lighting module is replaced by a more efficient one, the current through the multiple light sources needs to be adjusted. However, the existing lighting drivers (e.g., current drivers for the multiple light sources) are unaware of the new lighting module and will continue to supply the same current to the multiple light sources.

[0004] Therefore, the main issue when it comes to replacing luminaire modules is that the new combination of luminaire driver and luminaire board should be plug-and-play and work properly without any action from the user.

[0005] Typically, the light output of a luminaire module depends on the drive current (set by the driver) and the module's efficiency level. When replacing an existing luminaire module with an improved or new one (e.g., with higher efficiency), the drive current should be adequate to ensure the same light output as the original module.

[0006] In conventional lighting systems, when replacing a luminaire module and reprogramming the luminaire driver would be too complex for the user, the driver does not change the drive current because this requires specific tools and / or knowledge. Therefore, introducing a luminaire module with higher efficiency could result in potentially excessive light output. Summary of the Invention

[0007] The purpose of this invention is to provide improved serviceability for lighting systems when replacing luminaire modules.

[0008] This objective is achieved by the lighting module of claim 1, the device of claim 7, the driver of claim 11, the lighting system of claim 13, the method of claim 14, and the computer program product of claim 15.

[0009] According to the first aspect, a lighting module includes:

[0010] At least one light source; and

[0011] A current limiter is used to control the current flowing through at least one light source to a predetermined value;

[0012] The lighting module is configured to be connected to an external constant current driver.

[0013] Accordingly, current limiting / regulation functions are integrated into the luminaire module, ensuring that a new luminaire module will automatically operate at the desired current after replacement, provided the driver's output voltage is sufficient to achieve that current. Therefore, external drivers and luminaire modules can be automatically matched in a cost-effective manner.

[0014] According to the first option of the first aspect, the current limiter can be configured to control the current flowing through at least one light source to a target value set by the luminaire module, independent of the current source of the external driver. Thus, the current limiter of the luminaire module ensures an appropriate target value for the current through the (multiple) light sources of the luminaire module, regardless of the setpoint of the external driver.

[0015] According to the second option of the first aspect, which can be combined with the first option, the luminaire module may include a temperature sensing element or function for measuring the temperature of the current limiter, wherein the luminaire module can be configured to activate a switch if a predetermined over-temperature is measured by the temperature sensing element or function, the switch shunting the output of an external driver or bypassing the current limiter. This ensures that the current limiter is protected from over-temperature by excessive voltage that may be generated by a mismatched external driver.

[0016] According to the third option of the first aspect, which can be combined with the first or second option, the luminaire module may include a temperature sensing element or function for measuring the temperature of the current limiter, wherein the current limiter can be configured to increase a set point for current regulation or a bypass current sensing element if a predetermined over-temperature is measured by the temperature sensing element or function. This ensures that the current limiter is protected from over-temperature by excessive voltage that may be generated by a mismatched external driver, without deactivating the luminaire module or the current limiter.

[0017] According to the fourth option, which can be combined with any of the first through third options, the luminaire module may include a voltage sensing element or function for measuring the voltage across the current limiter, wherein the luminaire module is configured to activate a switch to bypass the current limiter when the measured voltage exceeds a predetermined threshold voltage. This ensures that the current limiter is protected from overheating by excessive voltage that may be generated by a mismatched external driver.

[0018] According to the fifth option of the first aspect, which can be combined with any of the first to fourth options, the current limiter may include a linear current regulating circuit or a current regulating diode. Thus, the current limiting function can be achieved without substantially increasing the circuit complexity of the luminaire module.

[0019] According to a second aspect (which relates to the driver side), an apparatus is provided for controlling a driver of an external luminaire module that can be connected to a lighting system, wherein the apparatus is configured to measure the output voltage applied to the driver of the connected luminaire module to determine whether the measured output voltage exceeds the operating range of the driver's current control mode, and if the measured output voltage exceeds the operating range (i.e., reaches the upper limit of operation), reduce the output current of the driver. Preferably, the output current of the driver is reduced such that the output current remains greater than zero. The object of the invention is not to stop providing current, such as in overvoltage protection, but to reduce the output current to other non-zero current values.

[0020] Therefore, in addition to the advantages mentioned above, when the lighting module leaves the current control mode, the current limiter of the lighting module can be protected from the effects of over-temperature and / or over-voltage caused by the increased output voltage of the driver.

[0021] According to the first option of the second aspect, which can be combined with any of the first to fifth options of the first aspect, the device can be configured to measure the output current of the driver and, if the measured output voltage exceeds the operating range, reduce the output current to the same value as the current consumed by the luminaire module. This measure ensures that the output voltage of the driver remains within the operating range of the current control mode.

[0022] According to the second option of the second aspect, which can be combined with the first option of the second aspect or any of the first to fifth options of the first aspect, the device can be configured to: if the measured output voltage exceeds the operating range, gradually decrease the set point of the output current until the driver returns to the operating range of the current control mode. This alternative also ensures that the output voltage of the driver remains within the operating range of the current control mode.

[0023] According to the third option of the second aspect, which can be combined with the first or second option of the second aspect or any of the first to fifth options of the first aspect, the device can be configured to control the driver to generate a pulsed output current, wherein the maximum value of the pulsed output current is equal to or greater than the operating range of the current control mode, and if the output voltage of the driver includes a pulse component, the presence of a mismatched luminaire module is determined. Thus, the proposed voltage measurement can be used, for example, to detect mismatched luminaire devices by means of flickering light emitted by the light source of the luminaire module.

[0024] According to a third aspect, a driver is provided that includes the means according to the second aspect.

[0025] According to the first option of the third aspect, which can be combined with any of the first to third options of the second aspect or any of the first to fifth options of the first aspect, the driver can be configured to output a constant current during current control mode (i.e., CC mode) and switch to voltage control mode (i.e., CV mode), wherein the driver outputs a constant voltage when the output voltage exceeds the operating range of the current control mode. Thus, the driver's output voltage can be used to detect whether a mismatched luminaire module is connected to the driver.

[0026] According to a fourth aspect, a lighting system is provided, comprising at least one driver according to a third aspect and at least one luminaire module according to a first aspect.

[0027] According to a fifth aspect, a method for controlling a driver in a lighting system is provided, wherein the method includes:

[0028] Measure the output voltage of the driver applied to the connected lighting module;

[0029] Determine whether the measured output voltage exceeds the operating range of the driver's current control mode; and

[0030] If the measured output voltage exceeds the operating range, reduce the driver's output current.

[0031] According to a sixth aspect, a computer program product is provided, which includes code means for generating the steps of the method described in the fifth aspect when run on a computer device.

[0032] Note that the above-described device may be implemented based on an arrangement of discrete hardware circuits, integrated chips, or chip modules having discrete hardware components, or based on a signal processing device or chip controlled by software routines or programs stored in memory, written on a computer-readable medium, or downloaded from a network such as the Internet.

[0033] It should be understood that the lighting module of claim 1, the device of claim 7, the driver of claim 11, the lighting system of claim 13, the method of claim 14, and the computer program product of claim 15 may have similar and / or identical preferred embodiments, particularly as defined in the dependent claims.

[0034] It should be understood that the preferred embodiments of the present invention may also be any combination of the dependent claims or the above embodiments with the corresponding independent claims.

[0035] These and other aspects of the invention will become apparent from the embodiments described below and will be elucidated with reference to the embodiments described below. Attached Figure Description

[0036] In the following figures:

[0037] Figure 1 A block diagram of a luminaire system having a driver and an enhanced luminaire module according to various embodiments is shown schematically;

[0038] Figure 2 The output characteristics of a driver with constant voltage (CV) mode are schematically illustrated.

[0039] Figure 3 The output characteristics of a driver with CV mode and constant power (CP) mode are schematically shown;

[0040] Figure 4 A block diagram of a driver according to various embodiments is shown schematically;

[0041] Figure 5 A flowchart of an enhanced luminaire driving process according to one embodiment is shown;

[0042] Figure 6 A flowchart of an enhanced luminaire driving process according to an alternative embodiment is shown;

[0043] Figure 7 A block diagram schematically illustrates a first example of an enhanced luminaire module according to one embodiment;

[0044] Figure 8 An example of a linear current regulator circuit that can be used in various embodiments is illustrated schematically;

[0045] Figure 9 A block diagram schematically illustrates a second example of an enhanced luminaire module according to one embodiment;

[0046] Figure 10 A block diagram schematically illustrates a third example of an enhanced luminaire module according to one embodiment;

[0047] Figure 11 A block diagram schematically illustrates a fourth example of an enhanced luminaire module according to one embodiment; and

[0048] Figure 12 A block diagram schematically illustrates a fifth example of an enhanced luminaire module according to one embodiment. Detailed Implementation

[0049] Various embodiments of the invention will now be described based on luminaires based on solid-state lighting systems. Solid-state lighting (SSL) is a type of lighting that uses semiconductor light-emitting diodes (LEDs), semiconductor lasers, vertical-cavity surface-emitting lasers (VCSELs), organic light-emitting diodes (OLEDs), or polymer light-emitting diodes (PLEDs) as light sources, rather than filaments, plasma (used in arc lamps such as fluorescent lamps), or gases. Furthermore, unlike incandescent bulbs (which use thermal radiation) or fluorescent tubes, solid-state electroluminescence can be used in SSL. Compared to incandescent lighting, SSL creates visible light with reduced heat generation and less energy dissipation. Moreover, white LEDs can use photoluminescence to convert blue light from solid-state devices into a (approximate) white light spectrum, which is the same principle used in conventional fluorescent tubes.

[0050] The following embodiments relate to LED luminaires. They can be implemented in conjunction with easy-to-service L2 (Level 2) boards and can be applied to any kind of standalone LED driver designed for the ease of service of the luminaire. However, it should be noted that the invention can be used in any kind of lighting equipment to enhance its serviceability.

[0051] A driver is an electronic device that regulates the power supplied to an LED or a string of LEDs. As the electrical characteristics of an LED change with temperature, the driver responds to these changes by supplying a constant amount of power to the LED. Drivers are crucial because LEDs require very specific electrical power to operate properly. If the voltage supplied to the LED is lower than the required voltage, very little current flows through the junction, resulting in low brightness and poor performance. On the other hand, if the voltage is too high, excessive current flows to the LED, and the LED may overheat and be severely damaged or completely fail (thermal runaway). This, of course, also applies to other types of lighting.

[0052] Figure 1 A block diagram of a luminaire system having a driver 110 and an enhancement luminaire module 120 (e.g., a secondary (L2) board, etc.) according to various embodiments is shown schematically.

[0053] Note that throughout this disclosure, unless specific additional functionality is involved, the structure and / or function of previously described blocks or circuit components with the same reference numerals are not described again. Furthermore, only those structural elements and functions that facilitate understanding the embodiments are shown. For the sake of brevity, other structural elements and functions have been omitted.

[0054] exist Figure 1 In an exemplary embodiment, the driver 110 is connected to the luminaire module 120 via two connection lines or wires 112. The luminaire module houses multiple solid-state light sources 121 (e.g., LEDs) and additionally houses a current limiter 132 for controlling and limiting the current through the light sources 121. The current limiter 132 may be a linear current regulating circuit (which can be obtained at low cost and in small size), such as a current regulating diode (CRD). The current limiter 132 may be implemented as an integrated circuit (e.g., Figure 1 The circuit of a chip or chip module (as shown) or a discrete circuit element.

[0055] In addition, driver 110 may include a user interface and / or input port 111 for setting driver parameters and / or supplying power to driver 110.

[0056] A current limiter 132 is provided on the lighting module 120 so that the current through the light source 121 of the lighting module 120 can be controlled by the lighting module 120, even though the driver 110 also operates as a current source.

[0057] In addition, some additional functions and / or components may be introduced at the driver 110 to minimize losses on the luminaire module, as described later.

[0058] Because the additional current control by the current limiter 132 of the luminaire module 120 may cause an initial mismatch between current supply and demand at the driver 110, the driver output voltage may drift toward the maximum permissible output voltage of the driver 110. This assumes that the constant current setting at the driver 110 is higher than the current consumed by the connected luminaire module 120, which is reasonable since the new luminaire module will most likely carry a light source with better efficiency.

[0059] Individually placed drivers are typically designed to output a constant current (CC) and maintain a constant voltage (CV) under open-circuit load or excessively high load voltage (e.g., LED string voltage). Such drivers are often referred to as CCCV drivers.

[0060] Figure 2 The output characteristics of a CCCV driver in constant voltage (CV) mode are schematically illustrated. In the diagram, the vertical axis corresponds to the driver output voltage V, while the horizontal axis corresponds to the driver output current I.

[0061] If the voltage V and current I of the load (e.g., the lighting module) fall within the operating point Figure 2 Within the operating window, CCCV drivers with this characteristic typically operate in CC mode, which is determined by the driver's maximum output voltage Vm and maximum output current Im. The load current can be set via the control interface 111 through a dimming tool or via the configuration tool of the driver 110, and the resulting voltage is determined by the LED load. Typically, this voltage falls within the limit Vm. When the load voltage V becomes too high (e.g., too many light sources in series (e.g., LEDs)) and exceeds the maximum output voltage Vm, the driver will exit the CC mode window and attempt to maintain a constant output voltage in CV mode, where the current I is no longer regulated. This means that the current I is then determined by the load.

[0062] Some drives may also have a so-called constant power (CP) mode, which is limited by the drive’s throughput power capability.

[0063] Figure 3 The output characteristics of a CCCV driver with CV mode and constant power (CP) mode are schematically illustrated. From Figure 3 As can be seen from the characteristics, the driver's operating window is limited not only by the maximum output voltage Vm and the maximum output current Im, but also by the maximum output power (i.e., the maximum product of the output voltage V and the output current I). This additional limitation of the maximum output power results in the upper right part of the operating window (where the output voltage and output current are high) being cut off.

[0064] In the example of a 40W indoor driver, the output voltage V can be limited to a maximum value of Vm = 54V, and the load current I can be set to a maximum value of Im = 1.1A. However, with a maximum output current Im of 1.1A, the maximum permissible output voltage drops to approximately 36V due to the 40W maximum power limitation.

[0065] However, when the luminaire module 120 has its own current limiter and the current is less than that generated by the driver 110, a voltage difference is generated across the current limiter 132 between the maximum output voltage Vm of the driver 110 and the voltage Vs across the light source 121 (e.g., a string of LEDs), resulting in energy dissipation as heat. This may be acceptable if Vs is close to Vm. However, if the voltage difference is too high, the resulting energy dissipation may be too high for the current limiter 132, and / or the power loss may be undesirable.

[0066] To address this power loss issue, additional measures were proposed for driver 110, as explained in the example below.

[0067] Figure 1 The driver 110 is configured to switch to CV mode when its maximum permissible output voltage Vm has been reached. As an additional measure, the driver 110 can be configured to sense the output current and reduce it to the same value as the current consumed by the luminaire module 120. Alternatively, after any maintenance or after each power-on, the driver 110 can gradually decrease its output current setpoint until it just exits CV mode and can then remain at that setpoint. This newly determined setpoint can be stored in the driver's internal non-volatile memory and used directly after the next power-on, eliminating the need for this process after each power-on. This is beneficial for component lifespan.

[0068] In these ways, the driver 110 will operate automatically with the correct current from the new luminaire module 120 without any action from the user.

[0069] Figure 4 A block diagram of a driver 110 according to various embodiments is shown schematically.

[0070] The driver 110 includes a driver circuit (D) 31 for generating a drive current to be supplied to the luminaire module 120 to activate and drive the light source 121. The driver circuit 31 is configured as a controllable current source to provide sufficient current to illuminate the light source 121 of the luminaire module 120 at the desired brightness, but to limit the current to prevent damage to the light source 121.

[0071] In addition, the driver 110 includes a current control circuit (I-CTRL) 32, which is connected to the output of the driver 110 and is configured (e.g., programmed) to measure the output voltage and control the driver circuit 31 to switch to CV mode when the maximum permissible output voltage Vm of the driver 110 is detected to have been reached.

[0072] Then, the current control circuit 32 measures the output current of the driver 110 and controls the driver circuit 31 to reduce the output current of the driver 110 to the same value as the current consumed by the lamp module 120 (i.e., the value of the measured output current).

[0073] Alternatively, after switching to CV mode, the current control circuit 32 of driver 110 can control driver circuit 31 to gradually decrease its output current setpoint until driver circuit 31 just leaves CV mode to return to CC mode. Then, the current control circuit 32 controls driver circuit 31 to maintain that setpoint.

[0074] Both driver circuit 31 and current circuit 32 receive their power supply P from a power supply circuit (not shown) inside or outside the driver 110.

[0075] The interface control circuit 32 can be implemented as a programmable processor controlled by software routines stored in program memory.

[0076] Figure 5 A flowchart of an enhanced lighting fixture driving process according to one embodiment is shown.

[0077] This process can be implemented in the driver 110, for example, through a software routine that controls the current control circuit 32.

[0078] In step S501, the output voltage Vo of the driver 110 is measured. This can be achieved, for example, by supplying the output voltage of the driver 110 to the analog-to-digital converter (ADC) directly or via a voltage divider, and storing the converted digital measurement value in a memory.

[0079] Then, in step S502, the measured voltage value of the output voltage Vo is compared with the maximum output voltage Vm, which can also be stored in the memory.

[0080] If in step S502 the measured value of the output voltage Vo is less than the maximum output value Vm ( Figure 5 The branch "N" used for "No" indicates CC operation mode, then the process ends because the output current required by the new luminaire module 120 matches the current supplied by the driver 110.

[0081] Otherwise, if the measured value of the output voltage Vo is greater than or equal to the maximum output value Vm ( Figure 5 If the "Y" branch indicates the CV operating mode, the process continues to step S503, and the output current Io of the driver, now determined by the lighting module 120, is measured. This can be achieved, for example, by allowing the output current to flow through a small shunt resistor or other current sensing element to obtain a measurement voltage, and providing the obtained measurement voltage directly or via a voltage divider to the analog-to-digital converter (ADC), and storing the converted digital measurement value corresponding to the measured value of the output current Io in memory. Alternatively, the output current amplitude may already be available within the driver 110.

[0082] Then, in step S504, the driver output current is set to and maintained at the measured value of the output current Io. Optionally, the driver 110 may (gradually) reduce its output current to the measured value consumed by the (new) luminaire module.

[0083] The local current limiter 132 on the luminaire module may eventually saturate during the control process at the driver 110, which could lead to a near short circuit and thus negligible power loss (i.e., the voltage drop across the current limiter 132 may become close to zero volts). In this way, a new operating point can be automatically established between the driver 110 and the new (more efficient) luminaire module 120.

[0084] Figure 6 A flowchart of an enhanced luminaire driving process according to an alternative embodiment is shown.

[0085] exist Figure 6 During the alternative lighting fixture driving process, in step S601, the output voltage Vo of the driver 110 is measured, such as... Figure 5 Step S501.

[0086] Then, in step S602, the measured voltage value of the output voltage Vo is compared with the maximum output voltage Vm, such as... Figure 5 Step S502.

[0087] Now, if in step S602 the measured value of the output voltage Vo is less than the maximum output value Vm ( Figure 6 If the branch "Y" indicates "yes", which indicates the CC operating mode, the process continues to step S603, in which the output current of driver 110 is maintained ("frozen") because it is within the operating window of driver 110.

[0088] Otherwise, if the measured value of the output voltage Vo is greater than or equal to the maximum output value Vm ( Figure 6 If the branch "N" indicates "No", which signifies the CV operating mode, the process branches to step S604, and the driver 110 gradually decreases the set point of the output current in small steps. Then, the process jumps back to step S601, and the output voltage Vo is measured again and then compared with the maximum output voltage Vm.

[0089] The cycle of steps S601, S602, and S604 continues until it is determined in step S602 that the driver 110 has left the CV mode, and the process continues to step S603, causing the driver 110 to remain at the set point.

[0090] Therefore, in Figure 6During the alternative luminaire driving process, the driver 110 will automatically operate at the correct current of the new luminaire module 120 without sensing the output current.

[0091] The above-mentioned characteristics of the process ( Figure 5 and Figure 6 This can be achieved using software programs that control the processor or analog control circuits in the feedback loop of the driver 110.

[0092] In the following text, see references Figures 7 to 12 An example is explained for implementing an enhanced luminaire module 120 with the proposed current limiter 132.

[0093] Figure 7 A block diagram of a first example of a lighting module 120 according to one embodiment is shown schematically.

[0094] A CCCV driver 110 powered by AC power supply 100 is connected to an enhanced luminaire module 120 including a current limiter 132. The current limiter 132 is connected in chain or series with the LEDs 121, thereby allowing the more efficient luminaire module 120 to be driven without replacing the existing driver 110, which outputs a higher current than the new luminaire module 120 requires.

[0095] Local current limiter 132 is configured to control the current through LED 121 to a set target value (which is lower than the output current of driver 110). Therefore, the output voltage of driver 110 increases due to excess current, and this excess current charges the internal output filter capacitor of the driver, and the output voltage quickly reaches the maximum output voltage Vm, thus driver 110 enters CV mode. With the current through LED 121 controlled by local current limiter 132, the new (more efficient) luminaire module 120 can operate at its desired current.

[0096] The current limiter 132 can be implemented by a commonly used current regulator circuit (e.g., a constant current source).

[0097] Figure 8 An example of a linear current regulator circuit that can be used as a current limiter 132 in various embodiments is illustrated schematically.

[0098] A first transistor Q1 is configured as a power transistor that controls the current through at least one LED U4, which is connected in series with and to the collector of the first transistor Q1. A second transistor Q2, having a collector resistor R2 (which provides base current to Q1), provides a feedback signal to the base of the first transistor Q1 based on the voltage generated at a current-sensing resistor Rs. The controlled current flowing through the series connection of LED U4, the first transistor Q1, and the current-sensing resistor Rs is determined by Vbe / Rs, where Vbe is the base-emitter voltage of the second bipolar transistor Q2, assuming that the voltage at the base resistor R1 of the second transistor Q2 can be ignored due to the small base current.

[0099] Therefore, in Figure 8 In the linear current regulator circuit, the current through LED U4 is regulated to the set value Io = Vbe / Rs by the first transistor Q1 via the feedback loop of the second transistor Q2. When the current Io attempts to increase from this set value, the base-emitter voltage at the second transistor Q2 increases, causing the collector-emitter voltage of the second transistor Q2 to decrease. Consequently, the base current of the first transistor Q1 decreases, and the current through LED U4 decreases again to its set value. When the current Io attempts to decrease from this set value, the base-emitter voltage at the second transistor Q2 decreases, causing the collector-emitter voltage of the second transistor Q2 to increase. Consequently, the base current of the first transistor Q1 increases, and the current through LED U4 increases again to its set value.

[0100] Of course, other available current regulating elements, circuits, or integrated circuits (ICs) can be used as the proposed current limiter 132. For example, an easy-to-use device that can be used as the proposed current limiter 132 is a so-called current regulating diode (CRD) or constant current diode, which provides a fixed current and has only two terminals.

[0101] The following second through fourth examples address the issue when the lighting module 120 is connected to a non-intelligent driver 110 (e.g., one that does not have the same connection characteristics as the previous examples). Figure 5 and Figure 6 When the current control function is described, the current regulator 132 may experience thermal overload due to excessive voltage.

[0102] Figure 9 A block diagram of a second example of an enhanced lighting module 120 according to one embodiment is shown schematically.

[0103] In the second example, an enhanced current limiter 132 is proposed for the luminaire module 120, which can protect itself from thermal overload. This can be achieved by providing the current limiter 132 with an integrated or external temperature sensing element or function. Figure 9 (Not shown) This is achieved by configuring the temperature sensing element or function to measure the temperature of the current limiter 132, and if it detects a predetermined over-temperature, the current limiter 132 activates the switch 133, which shunts the output of the current driver 132 (e.g., by (almost) short-circuiting through a low resistance value). Thus, the string 121 of the LEDs in the lighting module 120 and the current limiter 132 are shut off in the event of a thermal overload.

[0104] Figure 10 A block diagram schematically illustrates a third example of an enhanced lighting module 120 according to one embodiment.

[0105] Alternatively, when overheating is detected, the current limiter 132 can shunt itself. This can be achieved by providing a temperature sensing element 135, either inside or outside the current limiter 132, configured to measure the temperature of the current limiter 132 and, if it detects a predetermined overheat, activate a bypass (e.g., a (near) short circuit) of the current limiter 132's switch 134. Consequently, the LED 121 can experience a higher current than the current limiter 132 should guarantee. This problem will be addressed in... Figure 1 The fifth example shown is resolved. The additional bypass switch 134 is not always necessary. The current limiter 132 can increase the set point (target value) for current regulation or bypass the current sensing element (e.g., Figure 5 (The resistor Rs in the current limiter). Therefore, more current is allowed to pass through the current limiter, and the voltage across the current limiter 132 will be reduced, resulting in lower power loss.

[0106] In the second and third examples, the effect of the temperature protection control of the lighting module 120 can cause the string of LEDs 121 to flicker, which in turn warns the user or service personnel that the driver 110 in use is not suitable for the lighting module 120 and needs to be replaced.

[0107] Figure 11 A block diagram schematically illustrates a fourth example of an enhanced lighting module 120 according to an embodiment.

[0108] In the fourth example, overvoltage detection is incorporated into the current limiter 132. To achieve this, the luminaire module 120 includes a voltage sensing element or function 136, either inside or outside the current limiter 132, configured to sense the average or root mean square (rms) voltage on the current limiter 132, and to short-circuit the current limiter 132 via a bypass switch 134 when the voltage exceeds a predetermined threshold voltage (e.g., determined by the maximum power dissipated by the current limiter 132 under given application conditions) to prevent overheating damage.

[0109] The switch 133 in the second example and the bypass switch 134 in the third and fourth examples can be implemented by a semiconductor switch (e.g., a transistor, thyristor, or triac switch) with low on-resistance.

[0110] Figure 12 A block diagram schematically illustrates a fifth example of an enhanced lighting module 120 according to one embodiment.

[0111] In the fifth example, switch 134 is connected in series with current limiter 132 so that when temperature sensing element 135 detects that the temperature of current limiter 132 exceeds a predetermined over-temperature, the current through current limiter 132 is cut off (e.g., a thermostat switch or a reset over-temperature protector). That is, the overheat protection function of the fifth example shuts off current limiter 132 until it is cooled down. This will also cause the lamp to flicker and the driver current and voltage to change regularly, which can be diagnosed by the installer in the first case and / or by the diagnostic features in driver 110 in the second case.

[0112] In a modification of the fifth example, the series switch 134 may be omitted. Instead, the current limiter 132 can be configured to change the current limit to a lower value, where the power loss in the current limiter 132 is lower.

[0113] In the fifth example, the temperature sensing element 135 can also be integrated into the same housing as the current limiter 132, making it more practical.

[0114] The temperature sensing element 135 in the second, third, and fifth examples can be a negative temperature coefficient (NTC) thermistor, a resistance temperature detector (RTD, also known as a resistance thermometer), a thermocouple (e.g., two wires of different metals connected at two points), a semiconductor-based sensor (e.g., two identical diodes having temperature-sensitive voltage-to-current characteristics that can be used to monitor temperature changes), or other temperature-sensitive elements or circuits.

[0115] In another embodiment, driver 110 can be configured to detect whether it is connected to a new lighting module 120 that requires a higher current than the currently programmed output current of driver 110. For this purpose, current control circuitry 31 of driver 110 can be configured to control driver circuitry 31 to generate a pulsed output current, wherein the maximum value of the pulsed output current can be equal to or greater than... Figure 2 and Figure 3 The maximum current value Im of the driver output window is shown. The driver 110 can then detect (e.g., based on changes in its output voltage) whether the current limiter 132 is set on the lighting module 120 and limit the current. Pulsing of the output current can be performed so that the total power supplied to the lighting module 120 remains unchanged.

[0116] Furthermore, when different luminaire modules 120 are connected in parallel to the driver 110, the driver 110 can determine whether a mismatched luminaire module is connected by pulsed output current. For example, the first luminaire module requires a peak current of 350mA, while a newly inserted, higher-efficiency luminaire board is equipped with a current limiter 132 that limits the current to 300mA. The driver 110 can determine the presence of such a mismatched luminaire module by detecting the pulse component in the output voltage.

[0117] In summary, a current-limiting / regulating circuit has been described to ensure that the luminaire board will automatically operate at its desired current after replacement. Because current control at the luminaire board causes an initial mismatch between the driver's current supply and the luminaire board's demand, the driver's output voltage will drift towards the driver's maximum output voltage. When the maximum output voltage is reached, the driver is configured to operate in constant voltage (CV) mode, sensing the output current and reducing it to the same value as the current consumed by the current-controlled luminaire board. Alternatively, the driver can gradually decrease the output current setpoint until it just leaves CV mode and remains at that setpoint. In this way, the driver will automatically operate at the correct current for the newly installed luminaire board without any user intervention.

[0118] While the invention has been detailed and described in the accompanying drawings and foregoing description, such description should be considered illustrative or exemplary rather than restrictive. The invention is not limited to the disclosed embodiments. The proposed current limiter at the luminaire module and current control at the driver can be applied to any type of module provided in a driver-driven luminaire device and may be standardized within such modules.

[0119] By studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement other variations of the disclosed embodiments when practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. A single processor or other unit can implement the functions of several items as described in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not imply that combinations of these measures cannot be advantageously used. The foregoing description details certain embodiments of the invention. However, it should be understood that the invention can be practiced in many ways, however detailed the foregoing may appear, and is therefore not limited to the disclosed embodiments. It should be noted that the use of particular terms when describing certain features or aspects of the invention should not be construed as implying that the term is redefined herein as limited to include any particular characteristic of the feature or aspect of the invention associated with that term.

[0120] and Figure 5 and Figure 6 The processes illustrated can be implemented as program code devices for computer programs and / or dedicated hardware for receiver or transceiver devices, respectively. Computer programs can be stored and / or distributed on suitable media, such as optical storage media or solid-state media, supplied together with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

Claims

1. A constant current driver (110) comprising means for controlling the constant current driver (110), the means (32) being configured to measure the output voltage of the constant current driver (110) applied to a lighting module (120) to determine whether the measured output voltage exceeds the operating range of a current control mode of the constant current driver (110), and if the measured output voltage exceeds the operating range, to reduce the output current of the constant current driver (110). The device is configured to reduce the output current to the same value as the current consumed by the lighting module (120) if the measured output voltage exceeds the operating range by: Switch to constant voltage mode, measure the output current of the constant current driver (110) in constant voltage mode, set the output current to the measured output current, and return to constant current mode; or The constant voltage mode is switched to, and after switching to the constant voltage mode, the constant current driver (110) is adapted to gradually decrease its output current setpoint until the constant current driver (110) leaves the constant voltage mode to return to the constant current mode, and then maintains the setpoint.

2. The constant current driver (110) according to claim 1, wherein the device (32) is configured to switch to the constant voltage mode, and after switching to the constant voltage mode, the constant current driver (110) is adapted to gradually decrease its output current setpoint until the constant current driver (110) leaves the constant voltage mode to return to the constant current mode, and then maintains the setpoint, the operation being: After any maintenance or after each power-on, the constant current driver (110) is adapted to gradually reduce its output current to the set point until the constant current driver (110) leaves the constant voltage mode to return to the constant current mode, and then maintains the set point.

3. The constant current driver (110) according to claim 1, wherein the device (32) is configured to control the constant current driver (110) to generate a pulsed output current, wherein the maximum value of the pulsed output current is equal to or greater than the operating range of the current control mode, and the device (32) is configured to determine the presence of a mismatched luminaire module if the output voltage of the constant current driver (110) includes a pulse component.

4. The constant current driver (110) according to claim 1, wherein the constant current driver (110) is configured to output a constant current during the current control mode and is configured to switch to a voltage control mode when the output voltage exceeds the operating range of the current control mode, wherein the driver (110) outputs a constant voltage in the voltage control mode.

5. A lighting module (120), comprising: At least one light source (121); as well as A current limiter (132) is used to control the current flowing through the at least one light source (121) to a predetermined value. The luminaire module (120) is configured to be connected to a constant current driver (110), wherein the current limiter (132) is configured to, independently of the constant current driver (110), control the current flowing through the at least one light source (121) to a target value set by the luminaire module (120). The lighting module (120) mentioned above includes one of the following: - A temperature sensing element or function (135) for measuring the temperature of the current limiter (132), wherein the lamp module (120) is configured to: if a predetermined over-temperature is measured by the temperature sensing element or function (135), activate a switch (133; 134) that shunts the output of the constant current driver (110) or bypasses the current limiter (132). - A temperature sensing element or function (135) for measuring the temperature of the current limiter (132), wherein the current limiter (132) is configured to: increase a setpoint or bypass current sensing element for current regulation if a predetermined over-temperature is measured by the temperature sensing element or function (135); or - A voltage sensing element or function (136) for measuring the voltage across the current limiter (132), wherein the luminaire module (120) is configured to activate a switch to bypass the current limiter (132) when the measured voltage exceeds a predetermined threshold voltage.

6. The lighting module (120) according to claim 5, wherein the current limiter (132) comprises a linear current regulating circuit or a current regulating diode.

7. A lighting system, comprising: Constant current driver (110) and luminaire module (120). The constant current driver (110) therein is a constant current driver (110) according to any one of claims 1 to 4, and / or the lamp module (120) therein is a lamp module (120) according to any one of claims 5 or 6.

8. A method for controlling a constant current driver (110) in a lighting system, comprising: Measure the output voltage of the constant current driver (110) applied to the connected lighting module (120); Determine whether the measured output voltage exceeds the operating range of the current control mode of the constant current driver (110); If the measured output voltage exceeds the operating range, the output current of the constant current driver (110) is reduced; Measure the output current of the constant current driver (110); as well as If the measured output voltage exceeds the operating range, the output current is reduced to the same value as the current consumed by the lighting module (120) as follows: Switch to constant voltage mode, measure the output current of the constant current driver (110) in the constant voltage mode, set the output current to the measured output current, and return to constant current mode; or The constant voltage mode is switched to, and after switching to the constant voltage mode, the constant current driver (110) is adapted to gradually reduce its output current setpoint until the constant current driver (110) leaves the constant voltage mode to return to the constant current mode, and then maintains the setpoint.

9. A method for controlling a luminaire module (120) in a lighting system, comprising: The current flowing through at least one light source (121) is controlled to a predetermined value using a current limiter (132); A current source independent of the constant current driver (110) controls the current flowing through the at least one light source (121) to the set target value of the luminaire module (120); The method includes at least one of the following steps: The temperature of the current limiter (132) is measured, and the lamp module (120) is configured to activate a switch (133; 134) if a predetermined over-temperature is measured by a temperature sensing element or function (135), the switch (133; 134) shunt the output of the constant current driver (110) or bypass the current limiter (132). The temperature of the current limiter (132) is measured, and the current limiter (132) is configured to increase the set point for current regulation or bypass the current sensing element if a predetermined over-temperature is measured by the temperature sensing element or function (135). or The voltage across the current limiter (132) is measured, and the luminaire module (120) is configured to activate a switch to bypass the current limiter (132) when the measured voltage exceeds a predetermined threshold voltage.

10. A computer program product comprising, when run on a computer device, code means for generating the steps of claim 8.

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