Lighting fixture and method for providing various lighting outputs from a single light source

Abstract

An objective of the invention is achieved by a lighting fixture (10) for emitting one or more colours of light and a method (100) for controlling a light output of one or more sets of light emitting diodes (30) in a lighting fixture (10), wherein the lighting fixture comprises one or more sets of light emitting diodes (30) requiring a pre-determined current and voltage to emit light, a mode switching circuit (50) configured for switching between multiple lighting modes (61), wherein each lighting mode is defined by a light output of the one or more sets of light emitting diodes and said lighting mode is config- ured to supply the pre-determined current and voltage to the one or more sets of light emitting diodes (30), a memory circuit (60) configured for receiving the present lighting mode (63) from the mode switching circuit (50), storing the present lighting mode (63) as the stored lighting mode (64) and transmitting the stored lighting mode to the mode switching circuit, and / or the timer circuit (70) configured for tracking time and storing a reboot time measured between direct current (44) being switch off and on again, and transmitting the stored reboot time to the mode switching circuit (50), wherein the mode switching circuit (50) is configured with a pre-determined time threshold and configured to receive the reboot time from the timer circuit (70), wherein when the reboot time (72) is below the time threshold the mode switching circuit switches to a lighting mode (61) different from the stored lighting mode (64), wherein when the reboot time is above the time threshold the mode switching circuit switches to the stored lighting mode (64).

Description

[0001]Lighting fixture and method for providing various lighting output from a single light source Field of the Invention The present invention relates to lighting equipment, in particular a lighting fixture for emitting one or more colours of light, one or more colour temperatures and / or one or more different light intensities and a method for controlling a light output of one or more sets of light emitting diodes in a lighting fixture. Background of the Invention Lighting equipment for industrial application is a large field of technology, where a large amount of lighting is required to sufficiently illuminate the inside large buildings and large areas. The field has greatly been improved by fluorescent lamps, and especially fluorescent tubes, by providing a bright and broad-covering light output. Recently, the field has further been improved by light emitting diodes, which provide a compact lighting fixture size and a more energy-efficient light output. Furthermore, light emitting diodes enable a single lighting fixture to emit different col- ours of light with the same lighting pattern. Additionally, the different colours of light emitting diodes may be dimmed and combined or mixed to provide a very wide range of different colours of light. For agricultural buildings, the different colours of light may improve the productivity and / or welfare of farming animals. Prior art lighting equipment for industrial applications require expensive, complex and elaborate lighting controllers to provide a large lighting system which can switch be- tween different colours of light and / or dim the brightness. Hence, system specialists are required to install and program the lighting controllers for each application, thereby making such lighting products expensive for smaller industrial buildings. Object of the Invention One objective of the present disclosure is to provide one or more lighting fixture or a system of lighting fixtures which are simple and inexpensive to install, control and ex- pand. One further objective of the present disclosure is to provide a lighting fixture which can switch between different light outputs without requiring expensive extra equipment such as lighting controllers, which are often customized for each application. A further objective of the present disclosure is to provide a lighting fixture which is easy to customize to provide different light outputs or a mix of several light outputs during manufacturing. A further objective of the present disclosure is to provide an improved installation pro- cess wherein a plurality of lighting fixtures is easy to install in an existing building and connect together, so that one or more coherent lighting systems are provided. A further objective is to provide a lighting fixture which can withstand the harsh envi- ronmental conditions inside agriculture buildings. Description of the Invention One objective of the invention is achieved by a lighting fixture for emitting one or more colours of light. The lighting fixture comprises: - one or more sets of light emitting diodes requiring a pre-determined current and volt- age to emit light; - a mode switching circuit configured for: - switching between multiple lighting modes, wherein each lighting mode is defined by a light output of the one or more sets of light emitting diodes and the lighting mode is configured to supply the pre-determined current and volt- age to the one or more sets of light emitting diodes, - transmitting a present lighting mode and receiving a stored lighting mode; - a memory circuit configured for receiving the present lighting mode from the mode switching circuit, storing the present lighting mode as the stored lighting mode and transmitting the stored lighting mode to the mode switching circuit; - one or more power supply units configured for receiving a mains alternating current and supplying a direct current to the mode switching circuit and a timer circuit; and - the timer circuit is configured for tracking time and storing a reboot time measured between direct current being switch off and on again, and transmitting the stored reboot time to the mode switching circuit; wherein the mode switching circuit is configured with a pre-determined time threshold and configured to receive the reboot time from the timer circuit, wherein when the re- boot time is below the time threshold the mode switching circuit switches to a lighting mode different from the stored lighting mode, wherein when the reboot time is above the time threshold the mode switching circuit restores to the stored lighting mode. In one aspect, when the reboot time is less than the pre-determined time threshold, the mode switching circuit may switch the lighting mode to a subsequent lighting mode, i.e., it scrolls through each lighting mode in the sequence of multiple lighting modes sequentially. In another aspect, the switching circuit may jump through the sequence of multiple lighting modes in a different order. The order may be programmed by the user for convenience. The lighting fixture is intended to be part of a lighting system, wherein the lighting sys- tem comprises a plurality of lighting fixtures each powered by one or more common power lines connected to a power switch, dimmer or control circuit. A further embodi- ment of such lighting system is described in the present disclosure. Hence, the power switch enables control of the lighting modes of the plurality of lighting fixtures by being switched on and off in sequences being either faster than or slower than the pre-deter- mined time threshold. Due to a large amount of lighting fixtures being connected to a single power supply and power switch, during switching between the lighting modes a number of the lighting fixtures may become out of sync due to residual current and / or a difference in the indi- vidual timing circuits, e.g. when the power is switched close to the pre-determined time threshold. This problem is solved by the present invention. In one aspect, a sequence of multiple lighting modes comprises at least two lighting modes and may preferably comprise at least three or four lighting modes. The initial lighting mode may be the first lighting mode in the defined sequence, or it may be the lighting mode with a specific colour, such as white light, and / or it may be the lighting mode with the highest or lowest light intensity. The initial lighting mode may be pro- grammed into the mode switching circuit and / or the memory circuit, so that the lighting fixture is able to switch to the initial lighting mode without requiring to cycle through the entire sequence of multiple lighting modes. In one aspect of the lighting fixture, the lighting fixture may comprise one or more printed circuit boards (PCBs), wherein circuit components such as the sets of light emitting diodes (LEDs), mode switching circuit, memory circuit, power supply units (PSUs) and / or the timer circuit may be arranged on the one or more PCBs. One or more circuit components need not be provided separately, e.g., the mode switching circuit, memory circuit and timer circuit may be provided in one circuit component, e.g., an integrated circuit chip. The one or more PCBs and / or circuit components may be coated with a surface treatment, so that the components are resistant to air mixed with hazardous chemicals such as ammonia or other substances which may cause corro- sion such was vapour. In one aspect of the lighting fixture, one or more lenses may be arranged on the LEDs, wherein the lenses are configured to focus the light output of each LED, so that a wider or narrower beam width of the light output is achieved. One advantage of making the beam width wider is that a greater coverage area is achieved. One advantage of mak- ing the beam width narrower is that a greater light intensity is achieved for a narrower area. The lenses may be made of an acrylic plastic such as Polymethyl methacrylate (PMMA). A single lens may be configured to cover all LEDs or a plurality of lenses may be configured to over one or more LEDs. When the mains alternating current (AC) is disconnected from the one or more PSUs by the mains AC being switched off by a power switch or control circuit, the PSUs cease to supply direct current (DC) to the circuit components or at least to the mode switching circuit and the timer circuit. The timer circuit is configured to stay powered on for a specified time duration, so that it can record the reboot time. The specified time duration is at least as long as the time threshold. When the reboot time exceeds the specified time duration or the time thresh- old, the reboot time which is stored is at least longer than the time threshold. When the lighting fixture is connected to mains power, the timer circuit transmits the reboot time to the mode switching circuit, so that the mode switching circuit can switch to a lighting mode which is either the stored lighting mode or a lighting mode different from the stored lighting mode, depending on the reboot time compared to the time threshold. The specified time duration for which the timer circuit remains powered on may be provided by one or more energy storing capacitors. One advantage of using a capacitor is that the life span of the lighting fixture is increased compared to if the timer circuit was powered by a battery. The power which the capacitor should be capable of deliv- ering is minimal as the timer circuit only needs to track and store the reboot time until the reboot time is larger than the time threshold. The reboot time may be stored on non-volatile memory. In another aspect, the timer circuit may not be powered on through a specified time duration or during the entire time which the lighting fixture is not powered by mains AC. In this aspect, the timer circuit comprises circuitry configured to determine the amount of time which has passed while the lighting fixture was not powered. Hence, whether the pre-determined time threshold was exceeded or whether the measured reboot time is less than the time threshold may be determined once the lighting fixture is powered on again. When mains AC is supplied to the one or more PSUs and the lighting fixture is powered on, the memory circuit is configured to transmit the stored lighting mode to the mode switching circuit, so that if the reboot time is above the time threshold, the mode switch- ing circuit will switch to the stored lighting mode. The specific light output of each lighting mode is programmed so that the pre-deter- mined current and voltage for the sets of LEDs to emit the specific light output is sup- plied from the mode switching circuit to the sets of LEDs. The lighting modes may be provided as a combination of two different sets of LEDs so that e.g. a mixture of colour or intensity of light is provided. The one or more lighting modes may provide light output which is unique from the other lighting modes of the lighting fixture and / or the colour, colour temperature and / or intensity of light output of the one or more sets of light emit- ting diodes. One advantage is thus that the circuit components may be used for a wide range of different sets of LEDs and combinations of sets of LEDs. Thus, the manufac- turing of multiple different lighting fixture only varies by LEDs which are used, therefore the manufacturing process is faster and cheaper. One advantageous effect of providing the lighting fixture with the mode switching cir- cuit, the memory circuit and the timer circuit is that the lighting fixture can be installed on its own and still enable a user to use the single lighting fixture to emit different light outputs by simply rebooting the mains AC supplied to the lighting fixture with a general- purpose power switch, because the lighting fixture may provided with the required light output and lighting modes for specific applications and purposes by the manufacturer. no expensive or complex lighting controller is required to change a lighting inten- sity, colour, or colour temperature of the lighting fixture. Thus, an advantage is that the lighting fixture is simple, inexpensive and fast to install and it does not require any knowledge of a complex lighting controller to use the lighting fixture and adjust the light output. One further advantage is that several lighting fixtures may also be installed in parallel with each other and / or daisy-chained together, so that turning on and off the mains AC will make all lighting fixtures in parallel and / or a daisy-chain emit the same light output according to the selected lighting mode. One advantage of the lighting fixture is that it may enable a plurality of lighting modes to be provided and be used independently of each other. E.g. the light output of the lighting fixture is able to emit multiple different colours of light and / or emit light at mul- tiple different intensities by varying the voltage and current supplied to the sets of LEDs independently. As such, by varying the light output in terms of colours and / or intensi- ties, the lighting fixture is generally able to provide at least three lighting modes simply by performing one or more power-on and power-off sequences according to the de- scribed timer circuit and mode switching circuit. In a further embodiment of the lighting fixture the pre-determined time threshold of the mode switching circuit is in the range of 8 to 20 seconds, 10 to 17 seconds, or 12 to 15 seconds. The pre-determined time threshold is programmed into the mode switching circuit and may be re-programmed to a different threshold depending on the application. The lower limit of the time threshold is approximately 8 seconds, as setting a lower limit may be adversely affected by residual current in the one or more cables connecting the one or more lighting fixtures to mains AC or residual current in the one or more PSUs. Residual current may cause the PSU and as a consequence the other circuit compo- nents to remain powered on for a short period of time after the mains AC has been disconnected. As such the timer circuit may not properly start tracking time till after the residual current has dissipated or reduced to a minimum. Therefore, by programming the time threshold to be greater than 8 seconds, the adverse effects may be avoided entirely. On the contrary, programming the mode switching circuit to have a time threshold be- yond 20 seconds may be a disadvantage, since it makes the wait time too long for the user and hence forces the user to make consecutive rapid reboots to cycle to the de- sired lighting mode which is inconvenient. A longer wait time is also disadvantageous because it becomes harder for the user to count how much time has passed since turning off the mains AC. Furthermore, a longer time threshold may be disadvantageous in terms of how long the timer circuit needs to stay powered on after the mains AC is turned off to record the reboot time. In a further embodiment of the lighting fixture, the mode switching circuit switches to an initial lighting mode in a sequence of multiple lighting modes when the direct current has been switched off and on again within the pre-determined time threshold a pro- grammed number of times in a reset sequence The reset sequence may be performed by rapidly switching off and on the lighting fix- ture, wherein rapidly is defined as any time that is faster than the pre-determined time threshold. In one aspect, each power off and power on are to be made within the pre- determined time threshold, while the sequence of a given number of times of rebooting the lighting fixture in the reset sequence may be done over a longer period of time. In one scenario, where livestock animals are situated below the multiple lighting fix- tures, the animals may be stressed by multiple light switches, such as e.g. blinking lights, colour switching and / or dimming up and down. This problem is solved by the lighting fixture of the present invention as the reset sequence ensures that the lighting fixtures are not switched multiple times over a short time period when a reset is to be performed. In a further aspect, where the one or more lighting fixtures are connected to an external dimmer configured to dim the intensity of the light output, the user may preferably dim the light of the lighting fixture before performing the reset sequence in order to further reduce the risk of causing stress to the animals. In one aspect, a sequence of multiple lighting modes comprises at least two lighting modes and may preferably comprise at least three or four lighting modes. The initial lighting mode may be the first lighting mode in the defined sequence, or it may be the lighting mode with a specific colour, such as white light, and / or it may be the lighting mode with the highest or lowest light intensity. In a further embodiment of the lighting fixture, the programmed number of times in the reset sequence is preferably in the range of 2 to 10 times, or 3 to 9 times, or 4 to 8 times, or 5 to 7 times, or 6 times. One advantage of requiring at least three or more times in which the direct current has to be interrupted and resumed is that it is unlikely that a user would accidentally perform the reset sequence when setting out to switch to a different lighting mode or subse- quent lighting mode In a further embodiment of the lighting fixture, the one or more sets of light emitting diodes are configured to emit one or more different colours of light. Colours of light may be defined as static colours or combinations of different colours of light, e.g., combinations of two or more colours from a colour group comprising at least red, blue, green, orange, yellow, white, purple, cyan, magenta, etc. I.e., at least a mil- lion colour combinations may be provided by combining two or more colours. In a fur- ther aspect, two or more LEDs may produce a colour combination. In a further aspect, a single LED may provide the aforementioned colour combination. In a further embodiment of the lighting fixture, the one or more sets of light emitting diodes are configured to emit one or more different wavelengths of light. In one aspect the sets of LEDs may each be provided with different colour LEDs such as red, blue, green, orange, yellow, white, and / or ultraviolet such as UVA and UVC. When the lighting fixture comprises multiple sets of LEDs capable of emitting different wavelengths of light, i.e., different colour LEDs, lighting modes may be programmed so that the different sets of LEDs may be powered on and / or dimmed simultaneously to provide a colour mixture. In a further aspect, the lighting modes may be programmed so that the two or more sets of LEDs may be powered on and / or dimmed independently of each other. One general advantage of providing a lighting fixture which may be dimmed is that some animals are over-sensitive to bright light intensities, e.g., chickens, hence a dim- mable light will therefore properly accommodate such animals and hence improve wel- fare instead of disturbing the animals. One effect of providing sets of LEDs with e.g., red LEDs is that some livestock animals are not disturbed or awakened by red light during sleep, thus allowing personnel to see and work in a livestock building. One further effect of providing sets of LEDs with e.g., green or blue light is that the welfare and / or productivity of some livestock animals is improved when the animals reside and / or live below the specific colour of light. One effect of providing sets of LEDs with UVC LEDs is that the ultraviolet light may be used to break down contaminants, thus providing a cleaner environment in a given room such as a livestock building. One effect of providing sets of LEDs with UVA LEDs is that the ultraviolet light may be used to simulate sunlight, thus providing an improved day and night cycle for animals which may lead to an improved productivity and welfare for the animals. In one aspect, the lighting fixture may be provided with white LEDs and one or more different colour LEDs. The white LEDs may be selected from a specific colour temper- ature such as 3000, 4000 or 6000 Kelvin. The colour LEDs may be one of the afore- mentioned colours or any other colour which are desired by the end-user e.g. for use in an agricultural building. The white LEDs are intended to be used for a majority of the running time of the lighting fixture (e.g. to simulate daytime light), while the coloured LED such as a green LED, or blue LED and / or a combination thereof may be used for a specific re-occurring period of the livestock (e.g., during a mating or growth stage). In another example, the coloured LED may be a red LED which is advantageous during routine and maintenance work performed during nighttime. In such a case, the lighting fixture is advantageous as it provides both the white light and the coloured light in a single lighting fixture and enables an easy switch between the one or more lighting modes. Hence, the lighting fixture is much cheaper to install compared to installing a white light and a coloured light next to each other. In a further embodiment of the lighting fixture, the one or more sets of light emitting diodes are configured to emit one or more different colour temperatures. In one aspect the one or more sets of LEDs may each be provided with different colour temperature LEDs such as 2700, 3000, 4000 and / or 6000 Kelvin. In another aspect the colour temperature LEDs are white LEDs with a temperature in the range between 1000 and 10000 Kelvin. In one aspect by providing multiple sets of LEDs with different colour temperatures, powering on the multiple sets of LEDs simultaneously may be utilised to provide an intermediate colour temperature, e.g., providing one set with 2700 Kelvin LEDs with another set with 6000 K LEDs will combine to approximately a 4000 K light output. In a further aspect, the different LEDs may be arranged in a cyclic pattern on the PCB in order to ensure that the colour combination is as uniform as possible across all sets of LEDs. In a further aspect, one or more sets of white LEDs with a specific colour temperature may be combined with either a set of red or blue LEDs. In a further embodiment of the lighting fixture, one or more lighting modes are defined by the intensity of the light output of the one or more sets of light emitting diodes. In one aspect, the different intensities of the light output of the one or more sets of LEDs may be achieved by providing one or more different wattage levels, e.g., 12, 24 and 36 watts or 6, 18 and 24 watts. The specific wattage levels may be programmed into the mode switching circuit, so that a wide range of specific wattage levels are pro- vided. In another aspect, multiple independent wattage levels may be provided by program- ming the mode switching circuit. This may be achieved by the mode switching circuit providing each independent wattage level. The Independent wattage levels may be e.g., 3, 18 and 36 watts; 3, 12 and 24 watts; 3, 16 and 24 watts, etc. This is advanta- geous as it enables the lighting fixture to provide various different intensities of light output which are not a combination of at least two of the existing wattage levels, e.g. in existing lighting fixtures a third light output at 36 watts is a combination of the other light outputs 12 and 24 watt mode or a third light output at 24 watts is a combination of the other two light outputs of 6 and 18 watts. In another aspect, the intensity of the light output of the one or more sets of LEDs may be dimmable either by providing pulse-width modulation supply or by lowering the for- ward current of the LEDs, so that any intensity of light output is achievable. The dim- ming may be implemented through a Triode for Alternating Current (TRIAC) dimmer, thyristor, a 0-10V or 1-10V dimmer or similar dimmer technology. In another aspect, the herein disclosed embodiments of the LEDs which are configured to emit one or more colours of light and / or emit one or more colour temperatures can be dimmed and hence may be provided with the means for dimming the light intensity. One effect of providing one or more lighting modes wherein the intensity of the light output of one or more sets of LEDs are dimmable, is that the one or more lighting fixtures may save energy by being operated at a lower light output. In one aspect the lighting fixture may be provided with a number of different sets of LEDs, e.g., white light with a 4000 Kelvin temperature, a blue light and an UVA light. The lighting fixture may be configured with one or more lighting modes wherein two or more of the sets of LEDs emit light simultaneously and / or at one or more light intensi- ties, further lighting modes may be provided wherein the different sets of LEDs emit light independently and at one or more intensities. In a further example, the lighting fixture may comprise a white 3000 Kelvin temperature light, a red light and a blue light, wherein one or more lighting modes may be the blue light at one or more intensities and one or more further lighting modes may be the red and / or the white light at one or more intensities. In one aspect the timer circuit may be configured to detect if the power switch is mo- mentarily pressed for a short period of time while the lighting fixture is powered on. The short period of time may be 2, 3, 4, or 5 seconds. The detection of the continuous pressing of the power switch may be used to select an extra lighting mode different from the multiple lighting modes in the sequence of lighting modes. E.g., the extra light- ing mode may be a secondary dimming setting or a dynamic dimming, wherein the dynamic dimming is dependent on the short period of time which the power switch is pressed, i.e., if the switch is pressed for 2 seconds, the dimming setting is e.g.80%, if the switch is pressed for 2 seconds, the dimming setting is 60%, if the switch is pressed for 4 seconds the dimming setting is 40%, if the switch is pressed for 5 seconds the dimming setting is 20 etc. In another aspect, the dimming sequence is reversed so that the dimming may be increased from 0 to 100% by pressing for a longer period of time. In a further embodiment of the lighting fixture, the lighting fixture comprises at least a first set of light emitting diodes emitting a first light output and a second set of light emitting diodes emitting a second light output different from the first light output, wherein two or more lighting modes are configured for emitting the first light and the second light output, and at least one further lighting mode is configured for emitting a combination of the first and second light output, wherein the first and second light out- put are chosen between one or more different colours of light, one or more different colour temperatures and one or more intensities of the light output. In a further embodiment of the lighting fixture, the first and second set of light emitting diodes are individually dimmable. In another aspect, the lighting fixture may comprise a third, a fourth or any other amount of additional sets of LEDs, wherein each further set of LEDs emit a further light output different from the other light outputs. In one aspect, each set of LEDs may be individually dimmable when a lighting mode emits either only the first light output, the second light output or the combination of the first and second light output. The dimming may be provided by an external dimmer or lighting controller as described in this disclosure. One advantage achieved is that the lighting fixture controlled by the dimmer or lighting controller can provide dimming to three specific light outputs, i.e., the first light output, the second light output and the combination of the first and second light output. In another aspect, if the first set of LEDs are provided with one specific forward voltage and the second set of LEDs are provided with another forward voltage which is lower than the first set of LEDs, then when the combined light output is gradually dimmed, the first light output with the higher forward voltage will be turned off before the second light output with the lower forward voltage. In one example, this may be used to provide a lighting fixture which may produce a combined light output of red and white colours, e.g. the first set of LEDs is e.g., a 4000 Kelvin white and the second set of LEDs is red coloured light. As the combined light output is dimmed, at approximately 20% dimming the white light output will turn off and only the red light output will remain at the dimmed setting, hence as the combined light is dimmed from 100% brightness the red becomes more dominant. The red light may be continuously dimmable down to 0% dimming, where the red light may turn off. This is advantageous as in combination with the other lighting modes, the lighting fixture is capable of providing individual dimming of three different coloured light outputs. The same advantages may be achieved when combining a plurality of different light output colours, such as e.g., white, blue, green, UVA, UVC, etc. In a further embodiment of the lighting fixture, wherein the lighting fixture comprises at least three sets of light emitting diodes with at least three lighting modes, wherein the light output of each lighting mode is chosen between one or more different colours of light, one or more different colour temperatures and one or more intensities of light output. In a further embodiment of the lighting fixture, wherein the three sets of light emitting diodes are individually dimmable. In a further embodiment of the lighting fixture, the mode switching circuit is configured to switch to an initial lighting mode in a sequence of multiple lighting modes when the reboot time is above the pre-determined time threshold. The mode switching circuit may be configured to switch to a subsequent lighting mode in the sequence of multiple lighting modes when the reboot time is below the pre-de- termined time threshold. In this embodiment, the mode switching circuit may be configured to track the present lighting mode and the subsequent lighting mode, in order to switch to the subsequent lighting mode when the reboot time is below the pre-determined time threshold. In fur- ther aspect, the mode switching circuit may be programmed with an initial lighting mode which is the default lighting mode of the lighting fixture. In the embodiment, wherein the switching circuit switches to a different lighting mode or a subsequent lighting mode when the reboot time is below the pre-determined time threshold and switches to the initial lighting mode when the reboot time is above the pre-determined time threshold, the memory circuit may be implemented in a simple manner where it only tracks the present lighting mode, in order to determine the lighting mode which is switched to in the case of a short reboot time. While in terms of the longer reboot time, the mode switching circuit is programmed with the initial lighting mode, so that it does not need to receive a stored lighting mode in order to switch to the initial lighting mode when switching to the default. A sequence of multiple lighting modes comprising at least two lighting modes may be programmed into the mode switching circuit. One advantage of always resetting to an initial lighting mode may be that a memory circuit may not be required to store the present lighting mode as the stored lighting mode, and therefore the lighting fixture may be provided in a simplified version which is cheaper because it may not require a memory circuit or a complex memory circuit. In another aspect, the mode switching circuit may be configured to switch to the stored present lighting mode when the reboot time is above the time threshold and when the reboot time is below the time threshold the lighting mode is switched to the subsequent lighting mode in the sequence of multiple lighting modes. In this aspect, the reset se- quence may be used to force a reset to the initial lighting mode. One advantage of providing a sequence of lighting modes which may be configured for the one or more sets of LEDs, is that any number of light outputs from the sets of LEDs may be provided as different lighting modes which a user can switch between by using the lighting fixture and a power switch. In a further embodiment of the lighting fixture, the mode switching circuit is configured to restore the stored lighting mode when the reboot time is between the pre-determined time threshold and a second time threshold, and when the reboot time is above the second time threshold the mode switching circuit switches to an initial lighting mode in a sequence of multiple lighting modes. In one aspect, the second time threshold may be counted or measured after exceeding the pre-determined time threshold after powering off the lighting fixture. I.e., the mode switching circuit switches to the initial lighting mode after the total time of the pre-de- termined time threshold and the second time threshold added together has elapsed. One advantage of providing the second time threshold, where if the lighting fixture is powered on within the span of the second time threshold the stored lighting mode will be restored, is that it provides a grace period for the user to restore the stored lighting mode which was the present lighting mode before the lighting fixture was turned off. Hence, the user can avoid switching to a different lighting mode or a subsequent light- ing mode and avoid switching to the initial lighting mode, by making sure to turn on the lighting fixture within the span of the second time threshold. In a further embodiment of the lighting fixture, the second time threshold is in the range of 8 to 30 seconds, 12 to 25 seconds or 15 to 20 seconds. The span of the second time threshold between 8 and 30 seconds is advantageous as it allows the user enough time to consider their choice when operating the light switch connected to the lighting fixture, as the user will know that a quick reboot (below the second time threshold) will switch the lighting mode; a medium time reboot will restore the present lighting mode; and a long time reboot will switch to the initial lighting mode. In a further embodiment of the lighting fixture, a set of light emitting diodes comprises a plurality of single light emitting diodes arranged in series and / or parallel and where a plurality of light emitting diodes arranged in series are divided into sub-groups so that the sub-groups can be arranged in parallel. In another aspect, the lighting fixture may comprise multiple arrangements of a plurality of single LEDs arranged in series and / or parallel. In a further aspect, the LEDs in each plurality of single LEDS may be a single colour, wavelength or colour temperature or it may be two or more colours, wavelength or colour temperature arranged in series and / or parallel. A general challenge in designing lighting fixtures with multiple colour output and bright- ness dimming is that light emitting diodes with different colour or colour temperature requires different voltage and / or currents to emit a specific light output, thus leading to complex LED driver designs. Consequently, if the voltage and / or current supplied to the LEDs do not meet the requirements, the LEDs may flicker when emitting light or may even fail to emit light. This challenge has been solved by the present lighting fixture by providing a stabiliser arranged between the driver (i.e. the mode switching circuit) and the sets of LEDs, wherein the stabiliser is configured to reduce the flicker of the LEDs when the mode switching circuit dims the intensity of the light output. In one aspect, the stabiliser may be two electrolytic capacitors configured to filter the output electricity so that spikes and / or variations in the electricity are removed. In another aspect, the number of LEDs in each set of LEDs may be selected based on the forward voltage of each LED; the total voltage required to power the set of LEDs; the dimming of the intensity of the light output for each specific lighting mode and / or the required light output of the set of LEDs. The number of LEDs may need to be con- trolled when e.g., combining two or more different types of LEDs in a set of LEDs, e.g., when combining white LEDs with red LEDs or UVA LEDs with blue LEDs or any other colour. This is in part due to the general terms that e.g. white LEDs will turn off sooner as the forward voltage supply is reduced compared to the coloured LEDs with a lower forward voltage, e.g. during dimming of the light output. Hence, in one example where fewer white LEDs are provided compared to coloured LEDs with a lower forward volt- age, the white LEDs are capable of remaining powered on when supplied with the same forward voltage supply and thus may be dimmed to a lower brightness before turning off. In one example the white LEDs may be powered to 20% intensity instead of 60% intensity by providing at least one less white LED compared to the number of coloured LEDs. This is advantageous as it enables light output of different mixtures of colours and white light to be dimmable over a greater range of light output intensities by the lighting fixture without requiring a complex design of the mode switching circuit (LED driver). In another aspect, the same advantages may be achieved by providing one less LED with a higher forward voltage in each set of LEDs or each row of LEDs for the corresponding LED. By designing each set of LEDs and / or the driver according to the present disclosure, the present invention has achieved a very low flicker rate which is less than 1% and in some cases around 0,1% in standardised tests (e.g., as specified by the International Commission on Illumination (CIE), or International Electrotechnical Commission (IEC), etc.) for measuring flicker percent and flicker index, wherein flicker index is between 0 to 1. In another aspect the amount of flicker may be measured in PstLm or SVM. One advantage of providing a lighting fixture with a very low flicker rate is that animals occupying the agriculture buildings illuminated by the lighting fixture are not disturbed by the flickers. In particular, chickens are very sensitive to flickering. Thus, by ensuring a very low flicker rate, the lighting fixture can improve the productivity and welfare of the animals. Although for certain applications, such as livestock buildings, a low flicker rate is re- quired, the lighting fixture of the present disclosure is not limited to only being produced with a low flicker rate. In one aspect, the plurality of single LEDs arranged in series or parallel may be single LEDs of the same colour or colour temperature. Similarly, the sub-groups may also be single LEDs of the same colour or colour temperature. One effect of providing the single LEDs in series and / or parallel and sub-groups in parallel is that each set of LEDs with different colour and / or colour temperature can be designed to require the same voltage and current, hence each set ca be powered by the mode switching circuit through one or more lighting modes which are configured to supply the pre-determined current and voltage for a specific light output. As such, an advantageous effect is achieved because the circuit elements and design of the PSU and the mode switching circuit can be made more simple and cheaper, because each different set of LEDs require the same amount or fewer different amounts of voltage and / or current to provide the required light output. In a further embodiment of the lighting fixture, the lighting fixture comprises two elec- trical input terminals configured to receive mains alternating current and a first con- nector arranged at the two electrical input terminals, the first connector is adapted with a screw cap and an O-ring and configured to mate with a conducting cable comprising a second cable connector adapted with a thread, an O-ring and electrical terminals, so that an electrical connection and a water and dustproof seal is achieved when the first connector is mated with the second cable connector. The two electrical input terminals may be for a live and a neutral mains AC wire. In one aspect of the lighting fixture, the lighting fixture may comprise more than two electrical input terminals for receiving the mains alternating current. E.g., a third termi- nal may be used for a ground connection and multiple further terminals may be used for additional power phases and / or neutral wires or for signal wires for an optional light- ing controller. Preferably, the second cable connector may be a female-type connector and the first connector may be a male-type connector, as such the danger of being electrocuted by the second cable connector is reduced. One advantage of providing the first connector and the second cable connector is that when the two connectors are mated together, the O-rings and screw cap provide a water- and dustproof seal, which e.g. prevents short circuits and corrosion. A further advantage of providing two matching connectors is that connecting the light- ing fixture to a conducting cable is easy and efficient. In a further embodiment of the lighting fixture, the lighting fixture comprises two elec- trical output terminals connected to the two electrical input terminals and a second connector arranged at the two electrical output terminals, the second connector is adapted with a thread and an O-ring and configured to mate with a conducting cable comprising a first cable connector adapted with a screw cap, an O-ring and electrical terminals, so that an electrical connection and a water- and dustproof seal is achieved when the second connector is mated with the first cable connector. The two electrical output terminals may be connected to the live and neutral mains AC input of the two electrical input terminals. In a further aspect, the lighting fixture may comprise more than two electrical output terminals for receiving the mains alternating current. E.g., a third terminal may be used for a ground connection and multiple further terminals may be used for additional power phases and / or neutral wires or for signal wires for an optional lighting controller. Preferably, the second connector may be a female-type connector and the first cable connector may be a male-type connector, as such the danger of being electrocuted by the second connector is reduced. One advantage of providing the first connector and the second cable connector is that when the two connectors are mated together, the O-rings and screw cap provide a water- and dustproof seal, which e.g. prevents short circuits and corrosion. A further advantage of providing two matching connectors is that connecting the light- ing fixture to a conducting cable is easy and efficient. One effect of connecting the at least two electrical output terminals to the at least two electrical input terminals is that the mains alternating current received at the two elec- trical input terminals can be delivered to other lighting fixtures or nearby electrical ap- pliances. I.e., multiple lighting fixtures can be daisy-chained together, by conducting cables arranged between the first connector and the second connector of the multiple lighting fixtures. When multiple lighting fixtures are connected together in a daisy-chain, a further effect is achieved as all lighting fixtures can be turned on and off by interacting with a single power switch connected to the mains alternating current. In a further aspect an end cap may be arranged on the second connector, so that the at least two output terminals are protected when not being connected to a conducting cable. The end cap may be adapted according to the screw cap of the first cable con- nector, so that it may screw onto the thread of the second connector. A further objective of the invention is achieved by a lighting system comprising: - one or more lighting fixtures; - one or more detachable brackets clamped onto the lighting fixtures and fastened to a mounting surface; - a power switch to turn on and off a mains alternating current; - one or more first cables arranged between the power switch and the one or more lighting fixtures; and / or - one or more second cables arranged between multiple lighting fixtures wherein one or more lighting fixtures connected in series and / or parallel with other lighting fixtures and the power switch can be turned on and off by the power switch. In one embodiment of the lighting system, the one or more lighting fixtures are accord- ing to any one of the herein disclosed embodiments. Furthermore, the first and second cables may be the herein disclosed conducing cables. One advantage of providing a lighting system wherein multiple lighting fixtures are ar- ranged in series and / or parallel is that all lighting fixtures can be turned on and off by switching a single power switch, as such the lighting mode of each lighting fixture is also selected by a single power switch. In a rare event, the lighting mode of each lighting fixture in a large lighting system may become out of sync. To solve this problem, each lighting fixture may be configured to reset the present lighting mode to an initial lighting mode which may be the same for every lighting fixture in the lighting system. The reset may be performed by rebooting the mains AC supply three times rapidly. In a further embodiment of the lighting system, the lighting system comprises multiple lighting fixtures wherein the reset sequence is a common reset for said multiple lighting fixtures and is configured to switch the lighting mode to a common initial lighting mode for said multiple lighting fixtures. When multiple lighting fixtures are connected to a single power supply and power switch (e.g., through the one or more first and second cables), switching may cause the lighting fixtures to become out of sync in terms of the present lighting mode. The out of sync occurs due to residual current and / or a difference in the individual timing circuits of the lighting fixtures, e.g., when the power is switched close to the pre-deter- mined time threshold. This problem is solved by providing a forced reset to the common initial lighting mode after a reset sequence has been performed. The reset sequence may be performed by rapidly switching off and on the lighting fix- ture, wherein rapidly is defined as any time that is faster than the pre-determined time threshold. In a further embodiment of the lighting system, the lighting system comprises a light controller arranged between the power switch and the first cable, wherein the light con- troller is configured to turn on and off the mains alternating current using a timer and / or to dim the light output. In another aspect, the light dimmer may be arranged between the mains alternating current and the power switch. In a further aspect, a power timer may be arranged be- tween the dimmer and the power switch, wherein the power timer is configured to dis- connect the mains AC at a set time threshold or time of day. One advantage of providing a lighting system with one or more lighting fixtures which are simply controlled by being turned on and off, is that the lighting system may be controlled by a simple light controller which turns on and off the mains AC based on a timer set by a user. The light controller may be an Internet of Things device, which enables the user to remotely turn on and off the mains AC supply. The light controller may comprise a dimmer for dimming the light output of the lighting fixture, e.g., through a Triode for Alternating Current (TRIAC) dimmer, thyristor, a 0- 10V or 1-10V dimmer or similar dimmer technology. The dimmer of the light controller may be pre-configured with a specific dimming profile, or it may be controlled with a sensor such as a Luxmeter. A further objective of the invention is achieved by a method for controlling a light output of one or more sets of light emitting diodes in a lighting fixture comprising the acts of: - programming multiple lighting modes in a mode switching circuit wherein the lighting modes are defined by the light output of the one or more sets of light emitting diodes, wherein the lighting modes are configured to supply the pre-determined current and voltage to the one or more sets of light emitting diodes and programming a pre-deter- mined time threshold; - transmitting a present lighting mode from the mode switching circuit to a memory circuit, wherein the present lighting mode is the lighting mode currently being emitted by the one or more sets of light emitting diodes; - storing the present lighting mode as a stored lighting mode in the memory circuit and transmitting the stored lighting mode to the mode switching circuit; - supplying a direct current to the mode switching circuit and a timer circuit, wherein the direct current is generated from a main alternating current; - tracking time and storing a reboot time measured between the direct current being switched off and on again with the timer circuit; - transmitting the reboot time to the mode switching circuit; - switching to a lighting mode different from the stored lighting mode when the reboot time is below the pre-determined time threshold; - restoring the stored lighting mode when the reboot time is above the pre-determined time threshold; and - emitting a light output with the one or more sets of light emitting diodes corresponding to the lighting mode selected by the mode switching circuit. In another aspect, the method may comprise a further step of: - detecting a reset sequence when the direct current has been switched off and on again within the pre-determined time threshold a programmed number of times; - forcing a reset to an initial lighting mode in a sequence of multiple lighting modes. One advantageous effect is achieved by the act of programming the lighting modes, because this enables the manufacturer and / or user to adjust the light output of the one or more lighting modes to the exact specification for various LEDs and locations where the lighting fixtures are installed. In a further embodiment of the method, the lighting fixture is according to one or more of the herein disclosed embodiments. A further objective of the invention is achieved by a coupling fitting for coupling onto a round lighting fixture comprising: - a fitting body having a circular throughway with an open first end and an opposite closed second end, and comprising a first thread on an outer rim of the fitting body towards the open first end; - a locking cap comprising a tapered inner wall and a second thread configured to screw onto the first thread; and - a ring shaped collet with flexible arms arranged along the circumference of the collet and arranged in the open first end and extending into the throughway, wherein heads are arranged at a distal end of the flexible arms facing the fitting body and the flexible arms are configured to be compressed against the lighting fixture when the heads en- gage the tapered inner wall; wherein by turning the locking cap a locked position is provided when the collet is pulled to an outward position so that the lighting fixture is fixated, and wherein by turning the locking cap in the opposite direction an unlocked position is provided where the collet is pushed to an inward position so that the lighting fixture is released. A longitudinal axis is arranged along the extend of the throughway of the coupling fit- ting. An outwards moving direction is defined from the closed second end towards the open first end, and an inward moving direction is defined from the open first end to- wards the closed second end. A round lighting fixture may be a lighting fixture according to any one of the herein disclosed embodiments. In one aspect, the closed second end may define an inside volume of the fitting body when the lighting fixture is inserted into the throughway. In this inside volume one or more parts of the lighting fixture may be arranged, e.g., one or more cables connecting to the lighting fixture may be arranged here. In one aspect of the locking cap, the locking cap may be rotated in a clockwise direction to provide the locked position. Furthermore, the locking cap may be rotated in an anti- clockwise direction to provide the unlocked position. The rotations are around the lon- gitudinal axis. In one aspect of the coupling fitting, the looking cap may be entirely unscrewed from the first thread so that the throughway inside the fitting body is accessible and the inside of the screw cap is accessible. In one aspect of the collet, the collet may be removed from the locking cap by pushing the flexible arms together and pushing the collet outwards of the locking cap. One advantageous effect of the coupling fitting is that it is easy and fast to insert a lighting fixture into the throughway. Furthermore, the locking cap and the collet provide an easy and fast operation to fixate the lighting fixture to and release the lighting fixture from the coupling fitting. The insertion into the throughway may be in the inward direc- tion, and the release of the lighting fixture may be in the outwards direction. In one aspect of the coupling fitting, the fitting body may be made in a nylon material. One advantage of the nylon material is that it is strong and can withstand wear and tear. In a further embodiment of the coupling fitting, metal pieces are arranged at the distal end of the flexible arms on the opposite side of the heads, wherein the metal pieces are configured to grip onto the surface of the lighting fixture. In one aspect the metal pieces may be configured with a sharp edge which engages the surface of the lighting fixture. In another aspect the sharp edge may be configured to only engage and / or bite into the surface of the lighting fixture when the lighting fixture is moving in the outwards moving direction. One advantage of providing the metal pieces is that the fixation of the lighting fixture is stronger. In a further embodiment of the coupling fitting, one or more O-rings are arranged inside the throughway and configured to fit around the lighting fixture. In one aspect the one or more O-rings are arranged around the inside circumference of the throughway. One effect of arranging the O-rings inside the throughway and configuring the O-rings to fit around the lighting fixture and against the inner surface of the throughway, is that the lighting fixture which longitudinally is placed further into the throughway than the O-rings is sealed from the outside environment. Thus, the lighting fixture can be made dust- and waterproof at each end by being placed into the coupling fitting. A skilled person knows how to properly dimension the O-rings, so that a proper sealing effect is achieved. In a further embodiment of the coupling fitting, a collar is arranged between the one or more O-rings and the collet, and the collar is configured to retain the O-rings when the lighting fixture is pulled outwards. In one aspect the collar may be arranged loosely inside the throughway of the fitting body, so that it does not become stuck to the fitting body or the lighting fixture. The diameter of the collar may be the same diameter as the circle defined around the distal end of the flexible arms, so that the collar cannot become dislodged from the throughway. In a further embodiment of the coupling fitting, an outer surface of the fitting body com- prises a grove for mounting a clamp around the grove. In one aspect, the grove may be the same diameter as the lighting fixture, so that the one or more clamps can attach to either or both the grove and the lighting fixture. Thus making attachment of the lighting fixture and / or the coupling fitting to any surface, e.g., a roof or beam, easy. In a further embodiment of the coupling fitting, one or more apertures are arranged in the closed second end. In one aspect, one or more cables may be arranged into the apertures and connected to the lighting fixture inserted into the coupling fitting. In a further aspect, the cables may be configured with wire terminals and / or connectors for quickly being connected with one or more cables extending out of the lighting fixture. One advantage of providing multiple apertures is that each aperture may be used for separate cables, e.g., one aperture may be used for a cable with AC power input and the additional apertures may be used for daisy-chaining an AC power output to other lighting fixtures or other electrical products connected to the same circuit. In one aspect, if one or more of the apertures are not used, the unused apertures may be sealed by an end piece. The end piece is configured to ensure that the aperture is water- and dustproof. One advantage of providing additional apertures which may initially be unused, is that the coupling fitting allows the user to easily upgrade the lighting system by installing additional lighting fixtures and connecting them to AC power through the unused aper- tures. In a further embodiment of the coupling fitting, one or more cable glands are arranged in the one or more apertures for routing one or more cables to the lighting fixture ar- ranged inside the fitting body and seal the second end of the fitting body. In one aspect, the apertures may be provided with a thread wherein the cable glands can be fastened to the second end by being screwed into the thread of the aperture. Furthermore, the end piece used to block the unused aperture may also be provided with a thread, so that the end piece can be screwed into the thread of the aperture. One effect of using one or more cable glands is that the incoming cables are strain relieved by the cable gland and the cable entry in the cable gland provides a water- and dustproof seal, thus the inside volume of the fitting body is sealed from the outside environment. In one aspect, a single cable gland may be used wherein the cable gland is configured for receiving one or more cables through separate cable entries. One advantage of providing multiple cable entries is that each entry may be used for separate cables, e.g., one entry may be used for a cable with AC power input and the additional entries (exits) may be used for daisy-chaining an AC power output to other lighting fixtures or other electrical products connected to the same circuit. In a further embodiment of the coupling fitting, a diameter of the circular throughway is in the range of 28 to 80 mm, 35 to 70 mm, or 45 to 63 mm. The specific diameter of the circular throughway allows a circular object with the same diameter to be inserted into the throughway, e.g., the object may be a lighting fixture. The circular throughway may be made slightly larger than the specific diameter, e.g., in the range of 0.1 to 1 mm, so that a circular object that is exactly the specific diameter can fit into the circular throughway. One effect of making the diameter of the circular throughway in the range of 28 to 80 mm, is that the coupling fitting may be used for a wide range of products, e.g., different sizes of lighting fixtures or conduits. Description of the Drawing Various examples are described hereinafter with reference to the figures. Like reference numerals refer to like elements throughout. Like elements will, thus, not be described in detail with respect to the description of each figure. It should also be noted that the figures are only intended to facilitate the description of the examples. They are not intended as an exhaustive description of the claimed invention or as a limitation on the scope of the claimed invention. In addition, an illustrated example need not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular example is not necessarily limited to that example and can be practiced in any other examples even if not so illustrated, or if not so explicitly described. Exemplary embodiments of the invention are described in the figures, whereon: Fig.1a illustrates a circuit diagram of one embodiment of a lighting fixture Fig.1b illustrates a circuit diagram of one embodiment of a set of light emitting diodes Fig. 1c illustrates a circuit diagram of another embodiment of a set of light emitting diodes Fig.2a illustrates one embodiment of state diagram of the lighting modes of the mode switching circuit Fig. 2b illustrates another embodiment of state diagram of the lighting modes of the mode switching circuit Fig. 2c illustrates another embodiment of state diagram of the lighting modes of the mode switching circuit Fig.3a, 3b and 3c illustrates one embodiment of a lighting fixture Fig.3d illustrates another embodiment of the lighting fixture with an interchangeable lighting source. Fig.4a, 4b and 4c illustrates another embodiment of a lighting fixture Fig.5a through 5f illustrates several embodiments of conducting cables and connect- ors Fig.6 illustrates one embodiment of a method for controlling a light output Fig.7a illustrates one embodiment of a coupling fitting in a locked position Fig.7b illustrates one embodiment of a coupling fitting in an unlocked position Fig.7c illustrates one embodiment of a coupling fitting with a round object inserted Detailed Description of the Invention Exemplary examples will now be described more fully hereinafter with reference to the accompanying drawings. In this regard, the present examples may have different forms and should not be construed as being limited to the descriptions set forth herein. Ac- cordingly, the examples are merely described below, by referring to the figures, to ex- plain aspects. Throughout the specification, when an element is referred to as being “connected” to another element, the element is “directly connected” to the other element, “electrically connected”, “fluidic connected” or “communicatively connected” to the other element with one or more intervening elements interposed there between. The terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting. As used herein, the terms “comprises” “comprising” “includes” and / or “including” when used in this specification specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, oper- ations, elements, components, and / or groups thereof. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this invention pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be inter- preted in an idealized or overly formal sense unless expressly so defined in the present specification. Figure 1a illustrates a circuit diagram of one embodiment of a lighting fixture 10, wherein the lighting fixture 10 comprises a power supply unit 40 configured for receiv- ing a mains alternating current 42 from at least two electrical input terminals 17 con- nected to a live and a neutral wire and configured for supplying a direct current 44 and having a ground connection to ground 46. The mains AC 42 wires connected to the lighting fixture 10) may be connected to a power switch 88 (not part of the lighting fixture) in order to turn on and off the lighting fixture, i.e., perform a reboot of the AC supply. The lighting fixture 10 comprises a number of single light emitting diodes 31 (LEDs) arranged in sets of light emitting diodes 30. The illustrated set of LEDs 30 is arranged in parallel 33. A plurality of sets of LEDs 30 may be provided in the lighting fixture 10 to enable the lighting fixture 10 to emit different colours and / or colour temperature of light. Furthermore, the lighting fixture 10 comprises a mode switching circuit 50 configured to switch between multiple lighting modes, wherein each lighting mode defines a spe- cific light output which is emitted by the one or more sets of LEDs 30. Depending on the lighting mode, the mode switching circuit 50 supplies the required voltage and cur- rent to the one or more sets of LEDs 30. The multiple lighting modes are programmed into the mode switching circuit 50. The lighting fixture 10 comprises a memory circuit 60 which is configured to receive the current lighting mode from the mode switching circuit 50 and store it as a stored lighting mode. Additionally, the memory circuit 60 is configured to transmit the stored lighting mode to the mode switching circuit 50, when the direct current 44 is supplied to the mode switching circuit 50, e.g., after a reboot is performed. The lighting fixture 10 comprises a timer circuit 70 configured to track time between the direct current 44 being switched off and on again. The tracked time is stored as a reboot time once the lighting fixture 10 is rebooted, and the stored reboot time is then trans- mitted to the mode switching circuit 50. The mode switching circuit 50 is configured with a pre-determined time threshold pro- grammed into the mode switching circuit 50. When the mode switching circuit 50 re- ceives the reboot time from the timer circuit 70 following a power reboot, the mode switching circuit 50 is configured to switch to a lighting mode different from the stored lighting mode when the reboot time is below the time threshold, and when the reboot time is above the time threshold the stored lighting mode is restored from the memory circuit 60. Figure 1b illustrates a circuit diagram of one embodiment of multiple single light emit- ting diodes 31 arranged in series 32, the multiple single LEDs 31 constitute a set of light emitting diodes 30 or may be part of a larger set of light emitting diodes 30. Figure 1c illustrates a circuit diagram of one embodiment of multiple single light emitting diodes 31 in a set of LEDs 30, the set is arranged in sub-groups 34 comprising multiple single LEDs 31 in series 32, each sub-groups 34 are parallel 33 to each other. Figure 2a illustrates one embodiment of a state diagram of a sequence of multiple lighting modes 66 of the mode switching circuit. This embodiment of the mode switch- ing circuit is configured with a pre-determined threshold time and to switch between the multiple lighting modes 61 through a short reboot 72, which is shorter than the pre- determined threshold time, and a long reboot 74, which is longer than the pre-deter- mined threshold time. When the lighting fixture is powered on, the present lighting mode 63 is stored as the stored lighting mode 64 in the memory circuit. The mode switching circuit is configured to retain the present lighting mode 63 by re- storing the stored lighting mode 64 after a long reboot 74 is recorded by the timer cir- cuit. Furthermore, the mode switching circuit is configured to switch to one of the mul- tiple lighting modes 61 different from the present lighting mode 63 when a short reboot 72 is recorded by the timer circuit. Figure 2b illustrates another embodiment of a state diagram of a sequence of multiple lighting modes 66 of the mode switching circuit. This embodiment of the mode switch- ing circuit is configured to switch between the multiple lighting modes 61 through a short reboot 72 and a long reboot 74. When the lighting fixture is powered on, the present lighting mode 63 is stored as the stored lighting mode 64 in the memory circuit. The mode switching circuit is configured to always switch to an initial lighting mode 62 when a long reboot 74 is recorded. The initial lighting mode 62 may be the first lighting mode in the sequence of multiple lighting modes 66. Furthermore, when a short reboot 72 is recorded, the lighting mode is switched to a consecutive lighting mode 65 relative to the present lighting mode 63 in the sequence of multiple lighting modes 66. The illustration shows how after one short reboot 72 is done, the consecutive lighting mode 65 becomes the present lighting mode 63 (underscored), and this process may be repeated to cycle through the entire sequence of multiple lighting modes 66 as il- lustrated by the dashed line and dashed arrow. Figure 2c illustrates another embodiment of a state diagram of a sequence of multiple lighting modes 66 of the mode switching circuit. This embodiment of the mode switch- ing circuit is configured to switch lighting modes through a short reboot 72 and a long reboot 74. When the lighting fixture is powered on, the present lighting mode 63 is stored as the stored lighting mode 64 in the memory circuit. The mode switching circuit is configured to retain the present lighting mode 63 by re- storing the stored lighting mode 64 after a long reboot 74 is recorded by the timer cir- cuit. Furthermore, when a short reboot 72 is recorded, the mode switching circuit switches to a consecutive lighting mode 65 in the sequence of multiple lighting modes 66. This process may be repeated to cycle through the entire sequence of multiple lighting modes. When short reboot 72 is recorded, the consecutive lighting mode 65 becomes the present lighting mode 63 which is then stored in the memory circuit as the stored lighting mode 64, thus this mode can be recalled if a long reboot 74 is rec- orded, this is illustrated by the underscored numbers and the dashed arrows. Figure 3a illustrates one embodiment of a lighting fixture 10 in the shape of an elon- gated tube comprising a tube 16 and may be made of an acrylic material, e.g., polyme- thyl methacrylate (PMMA) and configured to reduce glare from the light emitting diodes by a part of the tube 16 being in a transparent material i.e. a diffuser. A part of the tube 16 may be made in a non-transparent material so that light does not illuminate out of this part of the tube 16, e.g. on the backside of the lighting fixture 10. One effect of providing the tube 16 in an acrylic material is that the tube 16 does not become stained and / or dissolve when placed in an environment where harsh chemicals such as am- monia are present in the air. The lighting fixture 10 furthermore comprises a first connector 12 arranged at one end of the lighting fixture 10 and a second connector 14 arranged at the opposite end of the lighting fixture 10. The first connector 12 comprises a screw cap and an O-ring for making the first connector 12 water- and dustproof, and at least two electrical input terminals. The two electrical input terminals are configured to receive an AC power input which is fed to the one or more power supply units of the lighting fixture 10. Figure 3b illustrates the same embodiment of the lighting fixture 10 as shown in figure 3a. In this illustration, the second connector 14 is illustrated. The second connector 14 comprises at least two electrical output terminals 18 configured for distributing an AC power output to additional lighting fixtures 10 or any other electrical circuitry. The two electrical output terminals 18 may be connected to the two electrical input terminals 17 through wires or through the PSU. Furthermore, the second connector comprises a thread for fastening another part to the second connector. The second connector may also comprise an O-ring for making the connector water- and dustproof. Figure 3c illustrates an exploded view of the lighting fixture 10 of the same embodiment illustrated in figure 3a and 3b. The diffuser 16 houses several components of the light- ing fixture 10. An electronics compartment 11 is arranged inside the diffuser 16, wherein the electronics compartment is configured to house the circuit components, e.g., the PSU, mode switching circuit, timer circuit, and / or the memory circuit. A heat sink 15 is arranged inside the diffuser 16, the heat sink may be configured as a reflector for reflecting light from the light emitting diodes. A printed circuit board 20 configured to hold one or more sets of light emitting diodes 30 is configured to be ar- ranged on the heat sink 15. Figure 3d illustrates another embodiment of the lighting fixture 10, wherein the lighting fixture 10 comprises a fixture base 13 configured to accommodate an interchangeable lighting source 19, e.g. in the shape and size of a standardised LED tube. Hence, the fixture base 13 may be any readily available tube sockets for standardised lighting tubes, e.g., T5, T8, T12, G5, G13, etc. The upper part of the figure illustrates a stand-alone interchangeable lighting source 19 and the lower part illustrates the interchangeable lighting source 19 arranged in the fixture base 13. The interchangeable lighting source 19 may be adapted in the same way as the lighting fixture illustrated in fig. 3a-3c with a standard tube connector at either end instead of the first connector 12 and the second connector 14. One advantage of providing an interchangeable lighting source 19 is that the light source is easily replaceable if damaged or when it exceeds it’s life span and fails to work. Another advantage is that the light source is easily changeable and upgradeable when a different light source with one or more different light outputs is required for a specific task. A further advantage is that the interchangeable lighting source 19, which is a lighting fixture according to the present invention, can be retrofitted into existing tube sockets. Figure 4a and 4b illustrate another embodiment of the lighting fixture 10 similar to figure 3a and 3b, wherein the lighting fixture 10 comprises a fixture base 13 configured for housing several components of the lighting fixture 10. Figure 4c illustrates an exploded view of the lighting fixture 10 of the same embodiment illustrated in figure 4a and 4b. This illustration shows how in this embodiment the heat sink 15 is integrated into the fixture base 13. The fixture base 13 is configured to house the electronics compartment 11. The fixture base 13 may be made in aluminium and coated to resist galvanic corrosion. Figure 5a illustrates one embodiment of a conducting cable 80, wherein the conducting cable 80 comprises a first cable connector 82 arranged at one end and a second cable connector 84 arranged at the opposite end. The first cable connector 82 is configured with a screw cap, electrical terminals and an O-ring, the first cable connector 82 is configured to mate with a second connector 14 of the lighting fixture 10 or a second cable connector 84 to form a water- and dustproof connection. The second cable connector 84 is configured with a thread and electrical terminals, the second cable connector 84 is configured to mate with a first connector 12 of the lighting fixture 10 or a first cable connector 82 to form a water- and dustproof connection. As such the conducting cable 80 is suitable to be arranged between two lighting fixtures 10 to daisy-chain the lighting fixtures. Figure 5b illustrates two embodiments of the conducting cable wherein the cables have been stripped to reveal the individual wires 86. The first embodiment on the left com- prises a first cable connector 82 and the second embodiment on the right comprises the second cable connector 84. The individual wires 86 are preferably capable of con- ducting a mains alternating current. The first cable connector 82 and the second cable connector 84 are equal to the embodiments described in figure 5a. The first cable con- nectors 82 is the same as the first connector 12 and the second cable connector 84 is the same as the second connector 14, where the first and the second connector 12,14 are arranged in each end of the housing of the lighting fixture 10, e.g. as illustrated in figure 3a, 3b, 4a and 4b. Figure 5c illustrates another embodiment of a conducting cable 80 wherein one end comprises the first cable connector 82 and the other end comprises the individual wires 86. For cable comprising five wires, e.g. for use with a 0-10V or 1-10V dimmer, the mating part of the first and second cable connector 82,84 may be swapped, so that the five- wire connectors are easily distinguishable from any 3-wire cables. In this case, the female-type and male-type electrical connectors as disclosed herein are not swapped, so that the wires are safe to use. Figure 5d illustrates another embodiment where the first cable connector 82 is con- nected to the second cable connector 84, where a water- and dustproof connection is achieved. Connection of the two cable connectors 82,84 is advantageous as it allows for extension of the conducting cables 80. The first cable connector 82 is illustrated on figure 5f and the second cable connector 84 is illustrated on figure 5e. Figure 6 illustrates one embodiment of a method 100 for controlling a light output of one or more sets of light emitting diodes 30 in a lighting fixture 10 comprising the acts of: - programming 110 multiple lighting modes 61 in a mode switching circuit 50 wherein the lighting modes are defined by the light output of the one or more sets of light emit- ting diodes 30, and the lighting modes are configured to supply the pre-determined current and voltage to the one or more sets of light emitting diodes and programming a pre-determined time threshold into the mode switching circuit 50; - transmitting 120 a present lighting mode 63 from the mode switching circuit 50 to a memory circuit 60, wherein the present lighting mode 63 is the lighting mode 61 cur- rently being emitted by the one or more sets of light emitting diodes 30; - storing 130 the present lighting mode 63 as a stored lighting mode 64 in the memory circuit 60 and transmitting the stored lighting mode 64 to the mode switching circuit 50; - supplying 140 a direct current 44 to the mode switching circuit 50 and a timer circuit 70, wherein the direct current is generated from a main alternating current 42; - tracking 150 time and storing a reboot time measured between the direct current 44 being switched off and on again with the timer circuit 70; - transmitting 160 the reboot time to the mode switching circuit 50; - switching 170 to a lighting mode 61 different from the stored lighting mode 64 when the reboot time 72 is below the pre-determined time threshold; - restoring 180 the stored lighting mode 63 when the reboot time 74 is above the pre- determined time threshold; and - emitting 190 a light output with the one or more sets of light emitting diodes 30 corre- sponding to the lighting mode selected by the mode switching circuit 50. In one aspect of the method 100, the act of switching 170 may be replaced by an act of cycling 171 where the light mode is switched to a consecutive light mode 65 relative to the present lighting mode 63 when the reboot time 72 is below the pre-determined time threshold. In another aspect of the method 100, the act of maintaining 180 may be replaced by an act of restarting 181 where the light mode is switched to the initial light mode 62 in the sequence of lighting modes 66 when the reboot time 72 is above the pre-deter- mined time threshold. Figure 7a illustrates one embodiment of a coupling fitting 200 provided in a locked position 202. The coupling fitting comprises a fitting body 210 having a circular through- way 211 on an inward facing side of the fitting body 210. The circular throughway 211 is open towards an open first end 212 and an opposite closed second end 214 is closed off. The outward facing side of the fitting body 210 towards the open first end 212 comprises a first thread 242. Furthermore, the coupling fitting 200 comprises a locking cap 240 with a second thread 243 configured to screw onto the first thread 242. The locking cap 240 is adapted with an open lid, which is aligned with and at least the same size as or lager than the circular throughway 211. As the locking cap 240 is screwed onto the coupling fitting 200, a top part 246 of the locking cap 240 extends beyond the fitting body 210 along a longitudinal axis substantially parallel to the circular throughway 211. The top part 246 comprises a tapered inner wall 244 which tapers from the second thread 242 inward towards the circular throughway 211. Furthermore, the coupling fitting 200 comprises a collet 220 comprising a ring 222 ar- ranged at the open first end 212 with a diameter and thickness substantially equal to the top part 246 of the locking cap 240. The collet 220 comprises a plurality of flexible arms 224 extending from the ring 222 into the throughway 211 towards the closed second end 214. Each flexible arms 224 comprises a head 225 facing the fitting body 210 at a distal end of the flexible arm 224, the heads 225 are configured to engage the tapered inner wall 244. When the heads 225 engage with the tapered inner wall 244, the flexible arms are pushed inward against the circular throughway 211 and may com- press against a round object arranged in the throughway 211 so that the object is fix- ated and fastened to the coupling fitting 200. Furthermore, the collet 220 is configured with metal pieces 226 arranged at the distal end of the flexible arms 224 on the opposite side of the heads 225. The metal pieces 226 are configured to grip onto the surface of the object inserted into the throughway 211. Furthermore, the coupling fitting 200 comprises a collar 230 and two O-rings 250 ar- ranged in a notch in the fitting body 210, so that the collar 230 and the O-rings 250 can fit into the fitting body 210 while allowing an object to enter the throughway 211 and pass through both the collar 230 and the O-rings 250. The O-rings are configured to touch the object inserted into the throughway 211, so that the inside volume 219 of fitting body 210 is sealed from outside moisture and dust. The collar 230 is configured to retain the O-rings 250 when an object is removed from the throughway 211, as such the collar 230 is configured as a ring with an inside opening large enough for the object to pass through and a ring thickness thick enough to engage against the collet 230, so that the ring does not fall out of the throughway 211 when pulled towards the open first end 212. The fitting body 210 may comprise an end stop 217 around the inside circumference of the fitting body 210. The inserted object engages the end stop 217 when the object is fully inserted into the fitting body 210. One advantage is thus that the installer will know when the object is correctly inserted, as the object cannot be pushed further in. The end stop 217 may be achieved by providing a grove 216 into the outside-facing surface of the fitting body 210. One advantage of providing the grove 216 is that a number of widely available clamps suitable for the specific grove diameter may be used to fasten the fitting body 210 to any surface, e.g. in an agricultural facility. Furthermore, the second end 214 is configured with two apertures 215. In this embod- iment the apertures 215 are configured with threads. Figure 7b illustrates the same embodiment of the coupling fitting 200 as illustrated in figure 7a. In this illustration the coupling fitting 200 is provided in the unlocked position 201. In the unlocked position 201, the locking cap 240 is unscrewed a couple of turns off the first thread 242, this provides room for the collet 230 to move along the longitu- dinal axis, and the room allows the heads 225 to not engage against the tapered inner wall 244, and thereby the inserted object is released from the hold of the collet 230, and the object can fully be withdrawn from and / or re-inserted into the throughway 211. From the unlocked position 201 and when the object is inserted into the throughway 211, the coupling fitting 200 may be put into the locked position 202 by turning the locking cap 240. Furthermore, cable glands 260 are arranged in the apertures 215 by being screwed into the thread of each aperture 215. The cable glands are configured for routing one or more cables to the inside volume 219 and seal the second end 214 of the fitting body 210 from moisture and dust. Figure 7c illustrates one embodiment of the coupling fitting 200 with a round lighting fixture 10 inserted into the throughway. The figure illustrates how the round lighting fixture 10 is inserted along the longitudinal axis 218 which is aligned with the through- way of the fitting body 210. As the locking cap 240 is completely screwed onto the first thread, and the collet 220 is pulled upwards relative to the fitting body 210, the coupling fitting is in the locked position 202, meaning the round lighting fixture 10 is fixated in the coupling fitting 200. Reference: Reference number: Lighting system 1 Lighting fixture 10 Method 100 Electronics compartment 11 Programming 110 First connector 12 Transmitting 120 Fixture base 13 Storing 130 Second connector 14 Supplying 140 Heat sink 15 Tracking 150 Diffuser 16 Transmitting 160 Electrical input terminals 17 Switching 170 Cycling 171 Electrical output terminals 18 Restoring 180 Restarting 181 Interchangeable lighting source 19 Emitting 190 Printed circuit board 20 Sets of light emitting diodes 30 Single light emitting diodes 31 Series 32 Parallel 33 Sub-groups 34First set of light emitting diodes35Second set of light emitting diodes36 Power supply units 40 Mains alternating current 42 Direct current 44 Ground 46 Mode switching circuit 50 Memory circuit 60 Multiple lighting modes 61 Initial lighting mode 62 Present lighting mode 63 Stored lighting mode 64 Sequence of multiple lighting modes 66 Timer circuit 70 Short reboot time 72 Long reboot time 74 Conducting cable 80 First cable connector 82 Second cable connector 84 Individual wires 86 Power switch 88 Coupling fitting 200 Unlocked position 201 Locked position 202 Fitting body 210 Circular throughway 211 Open first end 212 Closed second end 214 Aperture 215 Grove 216 End stop 217 Longitudinal axis 218 Inside volume 219 Collet 220 Ring 222 Flexible arms 224 Heads 225 Metal pieces 226 Collar 230 Locking cap 240 First thread 242 Second thread 243 Tapered inner wall 244 Top part 246 O-ring 250 Cable gland 260

Claims

CLAIMS 1. A lighting fixture (10) for emitting one or more colours of light, wherein the lighting fixture comprises: - one or more sets of light emitting diodes (30) requiring a pre-determined current and voltage to emit light; - a mode switching circuit (50) configured for: - switching between multiple lighting modes (61), wherein each lighting mode is defined by a light output of the one or more sets of light emitting diodes and said lighting mode is configured to supply the pre-determined current and volt- age to the one or more sets of light emitting diodes (30), - transmitting a present lighting mode (63) and receiving a stored lighting mode (64); - a memory circuit (60) configured for receiving the present lighting mode (63) from the mode switching circuit (50), storing the present lighting mode (63) as the stored lighting mode (64) and transmitting the stored lighting mode to the mode switching circuit; - one or more power supply units (40) configured for receiving a mains alternating cur- rent (42) and supplying a direct current (44) to the mode switching circuit and a timer circuit (70); and - the timer circuit (70) is configured for tracking time and storing a reboot time measured between direct current (44) being switch off and on again, and transmitting the stored reboot time to the mode switching circuit (50); wherein the mode switching circuit (50) is configured with a pre-determined time threshold and configured to receive the reboot time from the timer circuit (70), wherein when the reboot time (72) is below the time threshold the mode switching circuit switches to a lighting mode (61) different from the stored lighting mode (64), wherein when the reboot time is above the time threshold the mode switching circuit restore the stored lighting mode (64).

2. The lighting fixture (10) according to claim 1, wherein the pre-determined time threshold of the mode switching circuit (70) is in the range of 8 to 20 seconds, 10 to 17 seconds, or 12 to 15 seconds.

3. The lighting fixture (10) according to claim 1 or 2, wherein the mode switching circuit (50) switches to an initial lighting mode (62) in a sequence of multiple lighting modes (66) when the direct current (44) has been switched off and on again within the pre- determined time threshold a programmed number of times in a reset sequence,preferably the number of times in the reset sequence is in the range of 2 to 10 times, or 3 to 9 times, or 4 to 8 times, or 5 to 7 times, or 6 times.

4. The lighting fixture (10) according to any one of the preceding claims, wherein the one or more sets of light emitting diodes (30) are configured to emit one or more differ- ent colours of light.

5. The lighting fixture (10) according to any one of the preceding claims, wherein the one or more sets of light emitting diodes (30) are configured to emit one or more differ- ent colour temperatures.

6. The lighting fixture (10) according to any one of the preceding claims, wherein one or more lighting modes (61) are defined by the intensity of the light output of the one or more sets of light emitting diodes (30).

7. The lighting fixture (10) according to any one of the preceding claims, wherein a set of light emitting diodes (30) comprises a plurality of single light emitting diodes (31) arranged in series (32) and / or parallel (33) and where a plurality of light emitting diodes arranged in series are divided into sub-groups (34) so that the sub-groups can be ar- ranged in parallel.

8. The lighting fixture (10) according to any one of the preceding claims, wherein the lighting fixture (10) comprises at least a first set of light emitting diodes (35) emitting a first light output and a second set of light emitting diodes (36) emitting a second light output different from the first light output, wherein two or more lighting modes are con- figured for emitting the first light and the second light output, and at least one further lighting mode is configured for emitting a combination of the first and second light out- put, wherein the first and second light output are chosen between one or more different colours of light, one or more different colour temperatures and one or more intensities of the light output.

9. The lighting fixture (10) according to claim 8, wherein the first and second set of light emitting diodes (35,36) are individually dimmable.

10. The lighting fixture (10) according to any one of claims 1 to 7, wherein the lighting fixture (10) comprises at least three sets of light emitting diodes (30) with at least three lighting modes, wherein the light output of each lighting mode is chosen between oneor more different colours of light, one or more different colour temperatures and one or more intensities of light output.

11. The lighting fixture (10) according to claim 10, wherein the three sets of light emit- ting diodes (30) are individually dimmable.

12. The lighting fixture (10) according to anyone of the preceding claims, wherein the mode switching circuit (50) is configured to switch to an initial lighting mode (62) in a sequence of multiple lighting modes (66) when the reboot time is above the pre-deter- mined time threshold.

13. The lighting fixture (10) according to any one of claims 1 to 11, wherein the mode switching circuit (50) is configured to restore the stored lighting mode (64) when the reboot time is between the pre-determined time threshold and a second time threshold, and when the reboot time is above the second time threshold the mode switching circuit switches to an initial lighting mode (62) in a sequence of multiple lighting modes (66).

14. The lighting fixture (10) according to claim 13, wherein the second time threshold is in the range of 8 to 30 seconds, 12 to 25 seconds or 15 to 20 seconds.

15. The lighting fixture (10) according to any one of the preceding claims with a cou- pling fitting (200) for coupling onto the lighting fixture (10) comprising: - a fitting body (210) having a circular throughway (211) with an open first end (212) and an opposite closed second end (214), and comprising a first thread (242) on an outer rim of the fitting body (210) towards the open first end (212); - a locking cap (240) comprising a tapered inner wall (244) and a second thread (243) configured to screw onto the first thread (242); and - a ring shaped collet (220) with flexible arms (224) arranged along the circumference of the collet (220), and arranged in the open first end (212) and extending into the throughway (211), wherein heads (225) are arranged at a distal end of the flexible arms (224) facing the fitting body (210) and the flexible arms (224) are configured to be com- pressed against the lighting fixture (10) when the heads (225) engage the tapered inner wall (244); wherein by turning the locking cap (240) a locked position (202) is provided when the collet (220) is pulled to an outward position so that the lighting fixture (10) is fixated, and wherein by turning the locking cap (240) in the opposite direction an unlockedposition (201) is provided where the collet (220) is pushed to an inward position so that the lighting fixture (10) is released.

16. A lighting system (1) comprising: - one or more lighting fixtures (10) according to any one of the preceding claims; - one or more detachable brackets clamped onto the lighting fixtures and fastened to a mounting surface; - a power switch (88) to turn on and off a mains alternating current (42); - one or more first cables arranged between the power switch (88) and the one or more lighting fixtures (10); and / or - one or more second cables arranged between multiple lighting fixtures (10) wherein one or more lighting fixtures (10) connected in series and / or parallel with other lighting fixtures and the power switch can be turned on and off by the power switch (88).

17. The lighting system (1) according to claim 16, wherein the lighting system (1) com- prises multiple lighting fixtures (10) wherein the reset sequence is a common reset for said multiple lighting fixtures and is configured to switch the lighting mode (61) to a common initial lighting mode (62) for said multiple lighting fixtures (10).

18. The lighting system (1) according to claim 16 or 17, wherein the lighting system comprises a light controller arranged between the power switch (88) and the first cable, wherein the light controller is configured to turn on and off the mains alternating current (42) using a timer and / or to dim the light output.

19. A method (100) for controlling a light output of one or more sets of light emitting diodes (30) in a lighting fixture (10) comprising the acts of: - programming (110) multiple lighting modes (61) in a mode switching circuit (50) wherein said lighting modes are defined by the light output of the one or more sets of light emitting diodes (30), wherein the lighting modes are configured to supply the pre- determined current and voltage to the one or more sets of light emitting diodes and programming (110) a pre-determined time threshold; - transmitting (120) a present lighting mode (63) from the mode switching circuit (50) to a memory circuit (60), wherein said present lighting mode (63) is the lighting mode (61) currently being emitted by the one or more sets of light emitting diodes (30);- storing (130) the present lighting mode (63) as a stored lighting mode (64) in the memory circuit (60) and transmitting the stored lighting mode (64) to the mode switch- ing circuit (50); - supplying (140) a direct current (44) to the mode switching circuit (50) and a timer circuit (70), wherein said direct current is generated from a main alternating current (42); - tracking (150) time and storing a reboot time measured between the direct current (44) being switched off and on again with the timer circuit (70); - transmitting (160) the reboot time to the mode switching circuit (50); - switching (170) to a lighting mode (61) different from the stored lighting mode (64) when the reboot time (72) is below the pre-determined time threshold; - Restoring (180) the stored lighting mode (63) when the reboot time (74) is above the pre-determined time threshold; and - emitting (190) a light output with the one or more sets of light emitting diodes (30) corresponding to the lighting mode selected by the mode switching circuit (50).

20. The method (100) according to claim 19 wherein the lighting fixture (10) is accord- ing to one or more of claims 1-15.

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