[0001] This application claims priority from Australia Patent Application No. 2014203489, filed on 26 June 2014, Australian Patent Application No. 2014203489 is incorporated herein by reference in its entirety.

Technical Field of the invention

[0002] The present invention relates generally to light sensitive switches and, in particular, to switches that adapt to changing seasons.

Background

[0003] Increasing focus is being placed on electric power conservation and reduction, and particularly in th area of electric lighting, which is a major consumer of electric power.

[0004] "Sunset" switches typically operate in outdoor environments. These switches sense ambient light levels, and thereby detect sunset when the sun goes down, at which point they switch on one or more lights. The switches then detect sunrise when the sun comes up, at which point they switch the lights off. This ensures that the lights are on when they are needed, and are off during daylight hours, thus saving power.

[0005] More capable devices have also been developed, these including a programmable time which leave the light(s) switched on for a specified amount of time after the sun has set, and then switch the iight(s) off for the remainder of the night, when people are typically asleep and don't need illumination.

Summary

[0006] Disclosed are arrangements, referred to as Adaptive Light Sensitive Switch (ALSS) arrangements, which adapt the "on" and "off illumination periods during the night according to the duration of the night, or in other words to the season. Accordingly, during the summer months when the nights are relatively short, the ALSS arrangements switch the tight(s) on for a shorter time during the night In contrast, during the winter months when the nights are relatively long, the ALSS arrangements switch the light(s) on for a longer time during the night. [0007] A first aspect of the present invention provides an adaptive light sensitive switch, comprising a sensor for detecting an ambient light level value; a processor configured to communicate wit the sensor; and a memory for storing a computer executable computer program configured to direct the processor to adaptively switch a light on and off during a current night, the program comprising computer executable software code for: (a) receiving a first parameter value specifying a first proportion and a second parameter value specifying a second proportion; (b) storing information based on the output of the sensor; (c) determining, based upon said stored information, a duration of at least one calibration night, said at least one calibration night being prior to a current night; (d) estimating, based upon the duration of the at least one calibration night, a duration of the current night; (e) switching the light on at or near a sunset time immediately preceding the current night, for said first proportion of said duration of the current night, the light being switched on at a first predetennined .illumination level; (f) subsequently modifying the illumination level of the light to a second predetermined

illumination level for said second proportion of said duration of the current night; (g) subsequently further modi fying the illumination level of the light to a thi rd predetermined illumination level for a remainder of tire duration of the current night un til at or near a sunrise time immediately following the current night; and (h) repeating the steps (b) to (g) for a subsequent current night.

[0008] A further aspect of the present invention provides a a) receiving a first parameter value specifying a first proportion and a second parameter value specifying a second proportion; (b) detecting a plurality of ambient light level values using a sensor; (c) storing information based on the output of the sensor ; (d) determining, based upon said stored information, a duration of at least one calibration night, said at least one calibration night being prior to a current night; (e) estimating, based upon the duration of the at least one calibration night, a duration of the current night; (f) switching the light on at or near a sunset time immediately preceding the current night, for said first proportion of said duration of the current night, the light being switched on at a first predetermined illumination: level; (g) subsequently modifying the illumination level of the light to a second predetermined illumination level for said second proportion of said d uration of the current night; (h) subsequently further modifying the illumination level of the light to a third predetermined illumination level for a remainder of the duration of the current night until at or near a sunrise time immediately following the current night; and (i) repeating the steps (b) to (g) for a subsequent current night. [0009] A yet further aspect computer readable storage medium having a computer program recorded therein, the program being executable by a computer apparatus to make the computer perform a method of adaptively -switching a light on and off during a curretit night, said program comprising computer executable code for: (a) receiving a first parameter value specifying a first proportion and a second parameter value specifying a second proportion; (b) storing information based on the output of a sensor; (c) determining, based upon said stored information, a duration of at least one calibration night, said at least one calibration night being prior to a current, night; (d) estimating, based upon the duration of the at least one calibration night, a duration of the current night; (e) switching the light on at or nea a sunset time immediatel preceding the current night, for said first proportion of said duration of the current night, the light being switched on at a first predetermined illumination level; (f) subsequently modifying the illumination level of the light to a second predetermined illumination level for said second proportion of said duration of the current night; (g) subsequently further modifying the illumination level of the light to a third predetermined illumination level for a remainder of the durati on of the current night until at or near a sunrise time immediatel y followin the c urrent night: and (h) repeating the steps (b) to (g) for a subsequent current night

[0010] According to a further aspect of the presen t invention , tliere is provided an adaptive light sensitive switch comprising: a sensor for detecting an ambient light level value; a processor configured to communicate with the sensor; and a -memory for storing a computer executable computer program configured to direct the processor to adaptively switch a light on and off during a current night, the program comprising computer executable software code for:

(a) receiving a first parameter value specifying a first proportion and a second parameter value specifying a second proportion;

(h) storing information based on the output of the sensor;

(c) determining, based upon said stored information, a duration of at least one calibration night, said at least one calibration night being prior to a current night;

(d) estimating, based upon the duration of the at least one calibration night, a duration of the current night;

(e) switching the light on at or near a sunset time immediately preceding the current night, for said fi rst proportion of said duration of the current, night;

(f) subsequently switching the light off for said second proportion of said duration of the current night; (g) subsequently switching the light on for a remainder of the duration of the current night until at or near a sunrise time immediately fol lowing the current night; and

(h) repeating the steps (b) to (g) for a subsequent current night.

[005 i] According to another aspect of the invention, there is provided a method of adaptively powering a light during a current night, the method comprising the steps of:

(a) receiving a first parameter value specifying a first proportion and a second parameter value specifying a second proportion;

(b) detecting a plurality of ambient light level values using a sensor;

(c) storing information based on the output of the sensor;

< d) determining, based upon said stored information, a duration of at least one calibration night, said at least one calibration night being prior to a current night;

(e) estimating, based upon the duration of the at least one calibration night, a duration of the current night;

(f) switching the light on at or near a sunset time immediately preceding the current night, for said first proportion of said duration of the current night;

(g) subsequently switching the light off for said second proportion of said duration of the current night;

(h) subsequently switching the light on for a remainder of the duration of the current night until at or near a sunrise time immediately following the current night; and

(i) repeatin the steps (b) to (g) for a subsequent current night.

[0012] According to another aspect of the invention, there is provided a computer readable storage medium having a computer program recorded therein, the program being executable by a computer apparatus to make the computer perform a method of adaptively switching a light on and off during a current night, said program comprising computer executable code for;

(a) receiving a First parameter value specifying a first proportion and a second parameter value specifying a second proportion;

(b) storing information based on the output of a sensor;

(c) determining, based upon said stored information, a duration of at least one calibration night, said at least one calibration night being prior to a current night;

(d) estimating, based upon the duration of the at least one calibration night, a duration of the current night; (e) switching the light o at or near a sunset time immediately preceding the current night, for said first proportio of said duration of the current night;

(f) subsequently switching the light off for said second proportion of said duration of the current night; and

(g) subsequently switching the light on for a remainder of the duration of the current night until at or near a sunrise time immediately following the current night; and

(h) repeating the steps of (b) to (g) for a subsequent current night,

[0013] Other aspects of the invention are also disclosed, Brief Description of the Drawings

[0014] At least one embodiment of the present invention will now be described with reference to the drawings in which:

[0 15] Fig. 1 shows a functional block diagram of one ALSS arrangement;

[0016] Figs. 2 A and 2B collectively form a schematic block diagram representation of a controller used in Fig. 1 ;

[0017] Fig. 3 depicts the power conditioning module of Fig. 1 in more detail;

[0018] Fig. 4 is a flow chart of a process for adaptive])' powering a light according to one ALSS arrangement;

[001 ] Fig. 5 shows how the process of Fig. 4 determines the duration of the current night;

[0020] Figs. 6A and 6B respectively show how the ALSS process of Fig. 4 determines when to switch the light off and on;

[0021 ] Figs. 7A and 7B illustrate operation of one ALSS example system;

[0022] Fig, 8 is a flow chart of a process for adaptively powering a light according to a further ALSS arrangement; and [0023] Figs 9A and 9B illustrate operation of the ALSS example system of Fig. 8. Oetaiied Description including Best Mode

[0023] Where reference is made in any one or more of the accompanying drawings to steps and/or features, which have the same reference numerals, those steps and/or features have for the purposes of this description the same function(s) or operation(s), unless the contrary intention appeal's.

[0024] It is to be noted that the discussions contained in the "Background" section and the section above relating to prior art arrangements, relate to discussi ons of devices which may form public knowledge through their use, Such discussions should not be interpreted as a representation by the present inventors) or the patent applicant that such devices in any way form part of the common general knowledge in the art.

[0025] Fig. 3 shows a functional block diagram of one ALSS arrangement 100. An adaptive light sensitive switch 114 comprises a sensor 102 for detecting ambient light 101. The sensor outputs a light level value 117 that is proportional to the detected ambient light 101, and this light level value 1 17 is processed by a controller 104, the results of the processing being stored in a memory 209 (see Fig. 2 A).

[0026] In one ALSS arrangement, as the output light level .1 17 falls as nightfall approaches, the light level value 117 is compared to a pre-defined nightfall threshold value Xn. The time, defined as a sunset time Tn, at which the light level value 117 matches the threshold value .V//. is stored in the memory 209. Similarly, as the output light level 1 17 subsequently rises as daybreak approaches, the light level value 1 17 is compared to pre-defined daybreak threshold value Xd. The time, defined as a, sunrise time Td, at which the light level value 117 matches the threshold value Xd is stored in the memory 209. The aforementioned procedure takes place during what is referred to as a calibratio period. The difference between the sunset time Tn and the sunrise time Td ^' defined as tire duration D of a calibration night, where D = I ^' d- n.

[0027] In an alternate arrangement., the controller 104 typically stores, every Ts seconds, the light level value 1 17 from the sensor 02 and an associated time stamp. This results in storage of a continuous light level value profile having a 24 hour periodicity. If sufficient light level values have been stored during a 24 hour period, referred to as the calibration period, it is possible to detennine, from the stored profile and the pre-defined threshold values Xn and Xd, the sunset time Tn and the sunrise time Id at which sunset and sunrise respectively ca be said to have occurred during the calibration period (see a step 401 in Fig. 4), the aforementioned, sunset time and sunrise time defining the duration /.) of the calibration night. This information, i.e. the duratio of the calibration night, can then be used, prior to the sunset preceding a "current" night, to estimate the duration of the current night during which the adaptive "on" and "off" illumination periods can then be provided according to the ALSS arrangement.

[0028] In another arrangement, a single threshold value can be used to determine both the sunset time Tn and the sunrise time Id.

[0029] The controller 104 is described hereinafter in more detail in regard to Fig. 2A. The controller 104 outputs a control signal 1 18 to a powe conditioning module 1 12. The power conditioning module 1 1.2 is described hereinafter in more detail in regard to Fig. 3.

[0030] The power conditioning module enables electric power i 13 to .flow to a light 1 10. as directed by the control signal 1 18. Thus for example, the power conditioning module ca provide unrestricted power flow of the power 1 13 to the light 1 10, enabling the light 1 1 to provide maximum illumination. Alternately the power conditioning module can prevent the flow of power 1 13 to the light 1 1 , switching the light 1 10 off.

[0031] Furthermore, in some ALSS arrangements, the power conditioning module 1 12 can partially restrict the flow of the power 1 13 to the light 110, enabling a specified level of pow er to flow to the light 1 10, thus enabling the light 1 10 to provide a specified illumination level less than the maximum illumination. Thi can be effected using a Silicon Controlled Rectifier, for example. I other ALSS arrangements in which the light 1 10 has an inbuilt dimmer arrangement controllable by a control signal, the power conditioning module 1 .12 is configured to provide the control signal, depicted by a dashed arrow 1 1 , to a relevant control pott 120 on the light 1 10.

[0032] A use input/output interface 106 enables, in some ALSS arrangements, a user to provide inputs 107 to the controller 1 4, and to receive outputs from the controller 104. Thus for example the user may specify the following parameters, which are examples of parameters used in one ALSS arrangement: • the nightfall (sunset) threshold value Xn for use by a processor 205 to determine an ambient light level value La at which sunset is determined to occur;

* the daybreak (sunrise) threshold value Xd for use by the processor to determine an ambient light level value La at which sunrise is determined to occur;

• a parameter PI specifying a first proportion of the duration of a current night during which the light is to be switched on immediately after sunset;

• a parameter P2 specifying a second proportion of the duratio of a current night during which the light is to be switched off after it has been prev iously switched on:

* a parameter Ql specifying a first illumination level to be provided by the light during the first on period of the current night; and

* a parameter 02 specifying a second illumination level to be provided by the fight during the last on period of the current night.

[0033] In a further ALSS arrangement the user may specify parameter Q3 specifying a third illumination level to be provided by the light during the off period of the current night. The illumination level 03 normally relates to a dimmed illumination level. A dimmed illumination level is normally less than the maximum illuminatio level. In some arrangements, the dimmed level Q3 may be a lower illumination level than one of the levels Ql Operation of the ALSS arrangement using Q3 is described hereafter in relation to Figs, 8, 9A and 9B. The illumination levels Ql, Q2 and Q3 are essentially predetermined illumination levels of the l ight 1 10 set by the user.

[0034] The user I/O interface 106 can also, in some ALSS arrangements, provide the user with information, eg via an LCD display 214, about the current settings of the aforementioned parameters, In another ALSS arrangement, the I/O interface 106 ma be implemented using simple DIP switches, possibly including LED indicators. In yet another ALSS arrangement, one or more switches which form part of the I O interface 106 may be located remotely from the switch 104.

[0035] In some ALSS arrangements, I/O can be effected by a remote user / computer over a network 220, as depicted by an arrow 115. [0036] The ALSS arrangement subsystem depicted within a dashed boundary 1 16 is described hereinafter in more detail in regard to Fig. 2 A.

[0037] Figs. 7A and 7B illustrate operation of one ALSS example system.

[0038] Fig. 7.A shows an example in which, at the summer solstice, sunset occurs at 8:29pm, sunrise occurs at 5:58am, and accordingly the duration I) of the night is 9 hours and 30 minutes, in contrast, at the winter solstice, sunset occurs at 5: 14pm, sunrise occurs at 7:24am, and accordingly the duration D of the night is 14 hours and 12 minutes.

[0039] Fig. 7B shows performance of one ALSS arrangement which switches on the light 1.10 at sunset for a first proportion of the duration D of the night, being preset at 50% i the present example. The first proportion may be set by the user as desired. Thereafter, the light is switched off for a second proportion of the duration D of the night, being preset at 35% in the example. The second proportion may be set by the user as desired. The light is then switched on for the remainder of the duration D of the night, being 15% in the example.

[0040] Since D varies with the season, at the summer solstice the light is switched on at 8:29pm. and off at 1 : 15am, thus being on for 4 hours and 45 minutes which is 50% of the duration D of the night which is 9 hours and 30 minutes. The light is then off from 1 : 15 am until 4:35am, thus being off for 3 hours and 20 minutes which is 35% of the duration 1) of the night. The light is then on from 4:35am until 6:00am, thus being on for 1 hour and 25 minutes which is 15% of the duration D of the night. In all the light is on for 6 hours and 10 minutes; reflecting an energy- saving of 35% in comparison with leaving the light switched on from 8:28pm until 6:00am.

[0041 ] At the winter solstice the light is switched on at 5: 1 pm and off at 12:20am, thus being on for 7 hours and 6 minutes which is 50% of the duration D of the night which is 14 hours and 12 minutes. The light is then off from 12:20am until 5:20am, thus being off for 5 hours which is 35% of the duration D of the night. The light is then on from 5 :20am until 7:26am, thus being on for 2 hours and 6 minutes which is 15% of the duration I) of the night, in all the light is on for 9 hours and 12 minutes, reflecting an energy saving of 35% in comparison with leaving the light switched on from 5: 14pm until 7:26am.

[0042] Figs. 2A and 2B collectively form a schematic block diagram representation of the controller 104 used in Fig. 1, and collectively form a schematic block diagram of a general purpose electronic device including embedded components, upon which the ALSS methods to be described are desirably practiced.

[0043] As seen in Fig. 2A, the electronic device 104 comprises an embedded controller 202, Accordingly, the electronic device 104 may be referred to as an "embedded device." In the present example, the controller 202 has a processing unit (or processor) 205 which is bi- directionally coupled to the internal storage module 209. The storage module 209 m } be formed from non-volatile semiconductor read only memory (ROM) 260 and semiconductor random access memory (RAM) 270, as seen in Fig. 2B. The RAM 270 may be volatile, nonvolatile or combination of volatile and non-volatile memory.

[0044] The electronic device .104 may include a display controller 207, which is connected to a display 214, such as a liquid crysta display (LCD) panel or the like. The display controller 207 is configured for displaying graphical images on the display 214 in accordance with instructions received from the embedded controller 202, to which the display controller 207 is connected. In another ALSS arrangement, the display of output information may be effected by the use of f .F.Ds.

[0045] The electronic device 104 communicates with the user input devices i 06 which may be formed by keys, a keypad or like controls, in some implementations, the user input devices 106 may include a touch sensitive panel physically associated with the display 214 to collectively form a touch-screen. Such a touch-screen may thus operate as one form of graphical user interface (GUI) as opposed to a prompt or menu driven GUI typically used with keypad-display combinations. Other forms of user input devices ma also be used, such as a microphone (not illustrated) for voice commands or a joystk umb wheel (not illustrated) for ease of navigation about, menus.

[0046] As seen in Fig. 2A. in some ALSS arrangements the electronic device 1.04 ma also comprise a portable memory interface 206, which is coupled to the processor 205 via a connection 219. The portable memory interface 206 allows a complementary portable memory device 225 to be coupled to the electronic device 104 to act as a source or destination of data or to supplement the interna! storage module 209. Examples of such interfaces permit coupling with portable memory devices such as Universal Serial Bus (USB) memory devices, Secure I I

Digital (SD) cards. Personal Computer Memory Card International Association (PCM I A) cards, optical disks and magnetic disks.

[0047] In some ALSS arrangements the electronic device 104 may also have a communications interface 208 to permit coupling of the device 104 to a computer or communications network 220 via the connection 1 15. The connection 1 15 may be wired or wireless. For example, the connection 1 15 may be radio frequency or optical. An example of a wired connection includes Ethernet. Further, an example of wireless connection includes Bluetooth ¹ type local interconnection, Wi-Fi (including protocols based on the standards of the IEEE 802. i 1 family). Infrared Data Association (IrDa) and the like.

[0048] Typically, the electronic device 104 is configured to perform some special function, the ALSS arrangements in this case. The embedded controller 202, in conjunction with the special function components 1 1.6 (see Fig. 1), is provided to perform that special function. The special function component 1 16 is connected to the embedded controller 202.

[0049] The ALSS methods described hereinafter may be implemented using the embedded controller 202, where the processes of Figs. 4 to 6A, 6B may be implemented as one or more software application programs 233 executable within the embedded controller 202. The electronic device 104 of Fig. 2 A implements the described ALSS methods. In particular, with reference to Fig. 2B, the steps of the described ALSS methods are effected by instructions in the software 233 that are carried out within the controller 202, The software instructions may be formed as one or more code modules, each for performing one or more particular tasks. The software may also be divided into two separate parts, in which a first part and the corresponding code modules performs the described nietliods and a second part and the corresponding code modules manage a user interface between the first part and the user.

[0050] The software 233 of the embedded controller 202 is typically stored in the non-volatile ROM 260 of the internal storage module 209. The software 233 stored in the ROM 260 can be updated when required from a computer readable medium. The software 233 can be loaded into and executed by the processor 205. In some instances, the processor 205 may execute software instructions that are located in RAM 270. Software instructions may be loaded into the RAM 270 by the processor 205 initiating a copy of one or more code modules from ROM 260 into RAM 270, Alternatively, the software instaictions of one or more code modules may be pre-installed in a non-volatile region of RAM 270 by a manufacturer. After one or more code modules have been located in RAM 270, the processor 205 may execute software iiistroctions of the one or more code modules.

[0051] The application program 233 is typically pre-installed and stored in the ROM 260 by a manufacturer, prior to distribution of the adaptive light sensitive switch 1 14. However, in some instances, the application programs 233 may be supplied to the user encoded on one or more CD-ROM (not shown) and read via the portable memory interface 206 of Fig. 2 A prior to storage in the internal, storage module 209 or in the portable memory 225. in another alternative, the software application program 233 may b read by the processor 205 from the network 220, or loaded into the controller 202 or the portable storage medium 225 from other computer readable media. Computer readable storage media refers to any non-transitory tangible storage medium that participates in providing instructions and/or data to the controller 202 for execution and/or processing. Examples of such storage media include floppy disks, magnetic tape. CD- ROM, a hard disk drive, a ROM or integrated circuit, USB memory, a magneto-optical disk, flash memory, or a computer readable card such as a PCMCIA card and the like, whether or not such devices are internal or external of the device 104. Examples of transitory or non-tangible computer readable transmission media that may also participate in the provision of software, application programs, instructions and/or data to the device 104 include radio or infra-red transmission channels as well as a network connection to anothe computer or networked device, and the internet or Intranets including e-mail transmissions and information recorded on Websites and the like. A computer readable medium having such software or computer program recorded on it is a computer program product.

[0052] The second part of the application programs 233 and the corresponding code modules mentioned above may be executed to implement one or more graphical user interfaces (GUIs) to be rendered or otherwise represented upon the display 214 of Fig. 2A. Through manipulatio of the user input device 106 (e.g., the keypad), a user of the device 104 and the application programs 233 may manipulate the interface in a functionally adaptable manner to provide controlling commands and/or input to the applications associated with the GUl(s). Other forms of functionally adaptable user interfaces may also be implemented, such as an audio interface utilizing speech prompts output via loudspeakers (not illustrated) and user voice commands input via the microphone (not illustrated). [0053] Fig. 2B illustrates in detail the embedded controller 202 having the processor 205 for executing the application programs 233 and the internal storage 209. The internal storage 209 comprises read only memory (ROM) 260 and random access memory (RAM) 270. The processor 205 is able to execute the application programs 233 stored in one or both of the connected memories 260 and 270. When the electronic device 104 is initially powered up, a system program resident in the ROM 260 is executed. The application program 233 permanently stored in the ROM 260 is sometimes referred to as "firmware". Execution of the firmware by the processor 205 may fulfil various functions, including processor management, memory management, device management, storage management and user interface.

[0054] The processor 205 typically includes a number of functional modules including a conti ol unit (CU) 251 ₅ an arithmetic logic unit (ALU) 252 and a local or internal memory comprising a set of registers 254 which typically contain atomic data elements 256. 257, along with internal buffer or cache memory 255. One or more internal buses 259 interconnect these functional modules. The processor 205 typically also has one or more interfaces 258 for communicating with external, devices via system bus 281 , using a connection 2 1.

[0055] The application program 233 includes a sequence of instructions 262 though 263 that may include conditional branch and loo instructions. Tire program 233 may also include data, which is used in execution of the program 233. This data may be stored as part of the instruction or in a separate location 264 within the ROM 260 or RAM 270.

[0056] In general, the processor 205 is given a set of instructions, which are executed therein. This set of instructions may be organised into blocks, which perform specific tasks or handle specific events that occur in the electronic device 104. ^' Typically, the application program 233 waits for events and subsequentl executes the block of code associated wit that event. Events ma be triggered in response to input from a user, via the user input devices 1 6 of Fig. 2A, as detected by the processor 205. Events may also be triggered in response to other sensors and interfaces in the electronic device 104.

[0057] The execution of a set of the instructions may require numeric variables to be read and modified. Such numeric variables are stored in the RA 270. The disclosed method uses input variables 271 that are stored in known locations 272, 273 i the memory 270. The input variables 271 are processed to produce output variables 277 that are stored in known locations 278, 279 in the memory 270. Intermediate variables 274 may be stored in additional memory locations in locations 275, 276 of the memory 270. Alternatively, some intermediate variables may only exist in the registers 254 of the processor 205.

[0058] The execution of a sequence of instructions is achieved in the processor 205 by repeated application of a fetch-execute cycle. The control unit 251 of the processor 205 maintains a register called the program counter , which contains the address in ROM 260 or RA 270 of the next instruction to be executed. At the start of the fetch execute cycle, the contents of the memory address indexed by the program counter is loaded into the control unit 251. The instruction thus loaded controls the subsequent operation of the processor 205, causing for example, data to be loaded from ROM memory 260 into processor registers 254, the contents of a register to be arithmetically combined with the contents of another register, the contents of a register to be written to the location stored in another register and so on. At the end of the fetch execute cycle the program counter is updated to point to the next instruction in the system program code. Depending on the instruction just executed this may involve incrementing the address contained in the program counter or loading the program counter with a new address in order to achieve a branch operation.

[0059] Each step or sub-process in the processes of the methods described below is associated with one or more segments of the application program 233, and is performed by repeated execution of a fetch-execute cycle in the processor 205 or similar programmatic operation of other independent processor blocks in the electronic device 104.

[0060] The program 233 running on the microprocessor 205 can divide the night into segments during which the light 1 10, or other desired equipment, is switched on and off during the night The ALSS arrangement also can switch the light on just before dawn thereby offering savings in power use typically during the earl morning, but having the ability for the light to switch on some time before dawn.

[0061] The ratio of the adaptive lighting, ie the parameters PI, P2 can be specified by the setting of switches in the I/O interface 106, for example, that can var the ratios (proportions), to thereby offer the user an appropriate level of light at the right time and offer saving to the users. [0062] The ALSS arrangements determine the length of the night by determining the times of sunset and sunrise, and using that information, determine when to switch the light off and off to allow the power saving in the early morning but also allowing the light to switch on before dawn, to enable maximum utilisation of the light when it will be most required, while maximising power saving in a dynamic way where more power will be saved in the winter months (where more is used).

[0063] As the Adaptive Timing estimates the length of the night by measuring the times of sunset and sunrise, the timing automaticall adapts to the different seasons.

[0064] Fig. 3 depicts the power conditioning module 1 12 of Fig. 1 in more detail. The electric power 1 13 is directed to a switch 301 which may be implemented using a mechanical switching mechanism, or a solid state switching mechanism such as a Silicon Controlled Rectifier (SCR) or other device. The switch 301 is controlled by the control signal 1 18 from the controller 104. The switch 301 can be implemented by a mechanical switch such as a mechanical relay if the ALSS arrangement only needs to provide one level of illumination, in which event only one level of electric power ie full power need be delivered to the light 1 10 via the connection 1 1 1 . The switch 301 can be implemented by an SCR for example if the ALSS arrangement needs to provide various levels of illumination, in which various corresponding levels of electric power need to be delivered to the light 1 10 via the connection I I 1. Fig. 3 also shows the electric power 1 .1 being directed as depicted by a connection 302 to a step-down and filtering module 303 which provides the requisite power, typically 5VDC and the like, to the controller 104 and other modules in the ALSS, as depicted by arrows 304.

[0065] Fig, 4 is a flow chart of two process fragments 400 and 436, for adaptive ly powering a light according to one ALSS arrangement.

[0066] A first process fragment 436 relates to user specification of ALSS arrangement parameters. The process fragment 436 commences with a decision step 431 in which the processor 205 determines if the user wishes to enter and/or change any parameters (such as P P2 referred to above). If this is not the case, the process follows a NO arrow 435 from the step 431 back to the step 431 in a looping manner. If parameters are to be changed, the process follows a YES arrow 432 from the step 431 to a step 433 in which the processor 205 receives various parameter values via the user I/O interface 106, or the remote I/O 1 15. The process 436 then follows an arrow 434 back to the step 431.

[0067] A second process fragment 400 relates to the ALSS operation itself The process commences with a step 401 in which the processor 205 determines if sufficient usable light level values, detected by the sensor 102, have been stored in the memory to constitute what is referred to as a "night profile".

[0068] Thus for example, immediately after purchasing the ALSS, there will be no light level values stored in the -memory 209. Under these circumstances, the decision step 401 determines that no night profile has been stored, and the process 400 follows the NO arrow 402 to the step 403. Furthermore, if there is a power failure, the stored light level values may be inadequate to enable the adaptive sub-process (via an arrow 413) to be performed, and instead the default process (via the arrow 402) would be used.

[0069] If a night profile has been stored, then the process 400 follows the YES arrow 413 from the step 401 to a step 4.14 in which the processor 205 estimates the duration D of the current night. As noted, one of the advantages provided by the ALSS arrangements is that D is estimated every night, and varies with the time of year. The present ALSS arrangement estimates the length of the ight (ie /)) each ight by measuring a sunset time In and a sunrise time Td of the previous day, or a previous set of days, thus adapting the times during which the light is switched on and off during the night to the different seasons. This is described hereinafter in more detail in regard to Fig. 5.

[0070] The process 400 then follows an arrow 415 to a decision step 416 in which the processor 205 determines if an ambient light level ta(tl) presently being detected by the sensor 102 is less than a pre-determined sunset threshold Xn. If this is not the case, then sunset has not yet occurred, and the process 400 follows a NO arrow 417 .from the step 416 back to the step 416. If however the decision step 416 returns a "TRUE" logical value, then sunset has occurred and the process 400 follows a YES arrow 418 from the step 416 to a step 419.

[0071] In the step 41 the controller ^' 104 provides the requisite control signal 1 18 to the switch 301 in the power conditioning module in order to switch on the light 1 10 for a first proportion of the duration D of the current night. The light is either switched on a 100% illumination level, or at an illumination level Qi, depending on whether the ALSS arrangement in question provides for various illumination levels or not. The processor 205 also starts a timer.

[0072] The process 400 then follows an arrow 420 to a decision step 421. In the step 421, described hereinafter in more detail in regard to Fig. 6 A, the processor 205 determines whether it is time to switch off the light 1 10. If it is not yet time to switch the light I i 0 off, this decision depending upon the elapsed time according to the timer, then the process follows a NO arrow 422 from the step 421 back to th step 421 in a looping manner. If however it is time to switch the light off, then the process 400 follows a YES arrow 423 from the step 421 to a step 424 in which the processor 205 sends a control signal 1 18 to the switch 301 to switch off the light 101. The processor 205 also resets and restarts the timer.

[0073] The process 400 then follows a arrow 425 to a decision step 426. in the step 426. described hereinafter in more detail in regard to Fig. 6B, the processor 205 determines whether it is time to switch on the light 1 10. if it is not yet time to switch the light 3 10 on, this decision depending upon the elapsed time according to the timer, then the process follows a NO arrow 427 from the step 426 hack to the step 426 in a looping manner. If however it is time to switch the light on, then the process 400 follows a YES arrow 428 from the step 426 to a step 429 in which the processor 205 sends a control signal 1 18 to the switch 301 to switch on the light 101 at an. illumination level Q2 if the ALSS arrangement allows for this option. The process 400 then follows an arrow 430 to a decision step 408.

[0074] In the step 408 the processor 205 determines if an. ambient light level La(i2) presently being detected by the sensor 102 is greater than a pre -determi ned sunri se threshold Xd. If this is not the case, then sunrise has not yet occurred, and the process 400 follows a NO arrow 409 from the step 408 back to the step 408 in a looping manner. If however the decision step 408 returns a "TRUE" logical value., then sunrise has occurred and the process 400 follows a YES arrow 410 from the step 408 to a step 4.1 1. In the step 411 the processor 205 directs the switch 301 to turn the light 110 off. The process 400 then follows an arrow 412 back to the step 401.

[0075] The above description relates primarily to the situation in which a night profile has been stored, and as such the duration D of a previous night (or series of previous nights) is available. If however a night profile has not been saved, then the process 400 follows a default option, and follows a NO arrow 402 from the step 401 to a decision step 403 in which the processor 205 detenmnes if the ambient light level La(fl) presently being detected by the sensor 102 is less than the pre-determmed sunset threshold A'n. If this is not the case, then sunset has not yet occurred, and the process 400 follows a NO arrow 404 from the step 403 back to the step 403 in a looping manner. If however the decision step 403 returns a "TRUE" logical value, then sunset has occurred and the process 400 follows a YES arrow 405 from the step 403 to a step 406.

[0076] In the ste 406 the processor 205 directs the switch 301 to switch the light on (at an. illumination level Ql if the ALSS arrangement is so configured). The process 400 then follows an arrow 407 to the step 408.

[0077] Accordingly, according to a default option, the light 1 10 is switched on at or near sunset, stays on the entire night, and is switched off die at or near the following sunrise. During this 24 hour period however, a night profile will generally be detected by the sensor 102 and stored in the memory 209, after which the process 400 will follow ¹ the YES arrow 41 .

[0078] Fig. 5 shows how the process of Fig. 4 detemiines the duration of the current night in the step 414. in one ALSS arrangement, the step 414 commences with a step 501 in which the processor 205 reads ambient light level values stored in the memory 209, these having been stored during one or more calibration periods, in order to determine a time Tn at which the previous sunset occurred. The process 414 follows an arrow 502 to a step 503 in which the processor 205 reads ambient light level values stored in the memory 209 in order to determine a time Td at which the previous sunrise occurred. The process 414 then follows an arrow 504 to a step 505 in which the processor 205 determines the duration D of the previous night where in one example I) Td - Tn.

[0079] In one ALSS arrangement, the aforementioned value of D, relating to the previous night, is used for the current night, in another ALSS arrangement, the processor retrieves a series of Tn and Td values, associated with a corresponding series of previous nights, from the memory 209, and determines an average value for D for the series of previous nights. This can be used to compensate for cloudy conditions which could otherwise render a single Tn/Td pair of values inaccurate.

[0080] The process 414 then follows the arrow 416 to the step 416 in Fig. 4. [0081 ] Figs. 6A and i»B respectively show how the AL ^' SS process of Fig. 4 determines when to switch the light off and on.

[0082] Fig. 6A shows one ALSS example in which the step 421 determines whether it is time to switc the light 1 10 off by determining whether the elapsed time accumulated by the timer referred in the step 41 , referred to as timer, is greater than (Pl)(D), where PI is the parameter specifying the first proportion of the duration of the current night dining which the light, is to be switched on immediatel after sunset. If th timer has not yet run for a period greater than (Plj(D), then the process 42 follows the NO arrow 422 hack to the step 421 in a looping manner, if however the timer has run for a period greater than (Pi )(})).. then the process 421 follows: the YES arrow 423 to the step 424 in Fig. 4 which switches off the light, and resets and restarts the timer.

[0083] Fig. 6B shows one ALSS example in which the step 426 determines whether it is time to switch the light 110 on by determining whether the elapsed time accumulated by the timer referred in the step 424, referred to as timer, is greater than (P2)(D), where P2 is the parameter specifying the second proportion of the duration of the current night during which the light is to be switched off after it has been previously switched on. if the timer has not yet run for a period greater than (P2j(D) then the process 426 follows the NO arrow 427 back to the step 426 in a looping manner. Tf however the timer has run for a period greater than (P2)(D), then the process 426 follows the YES arrow 428 to the step 429 in Fig. 4 which switches on the light.

[0084] Fig. 8 shows a process 800 for a second arrangement of the ALSS system. In some instances, the user may desire the light to be left on at a dimmed illumination level during the night and specifies the illumination level Q3. The level 03 is specified according to the process 436 of Fig. 4. Level Q3 relates to an illumination at whic the light is to be left on during the "off period" of the night, and normally relates to a dimmed level of light, e.g., 50% of the maximum illumination level or 50% of one of the levels Ql or 02. As shown in Fig. 8, the process 800 includes the steps 401 to 41 1 as described in relation to the process 400 of Fig. 4. Further, the process 800 incl des steps 401 to 41 as described above in relation to the process 400 of Fig. 4. The process 800 then proceeds from step 419 to step 821 as shown in Fig. 8.

[0085] In the step 821 the processor 205 determines whether it is time to modify illumination of the light 1 10, in a similar manner to that described above in relatio to Fig. 6 A for determining time to switch the light 1 10 off. If it is not yet time to modify illumination of the light 1 f 0, this decision depending upon the elapsed time according to the timer, then the process follows a NO arrow 822 from the step 821 back to the step 821 in a looping manner. If however it is time to modify ilhimmation of the light 1 10, then the process 800 follows a YES arrow 823 from the step 821 to a step 824. At step 824, the processor 205 sends a control signal 1 18 to the switc 301 to modify the illumination level of the light 101 to the level Q3. The processor 205 also resets and restarts the timer.

[0086] The process 800 then follows an arrow 825 to a decision step 826. In the step 826 the processor 205 determines whether it is time to further modify the illumination level of the light 1 10 to the level Q2, The processor 205 determines whether it is time to modify the illumination level of the light 1 10 in the manner described above in relation to Fig. 6B fo determining whether it is time to turn on the light 1 10. If it is not yet time to modify the illumination level of the light 110, this decision depending upon the elapsed time according to the timer, then the process follows a NO arrow 827 from the step 826 back to the step 826 in a looping manner. If however it is time to modify the illumination level of the l ight 1 10, then the process 800 follows a YES arrow 828 from the step 826 to a step 829. In step 829 the processo 205 sends a control signal. 1 18 to the switch 301 to further modify ilhimmation of the light 1 10 to the ilhimmation level Q2. The process 800 then follows an arrow 430 to a decision step 408, and continues in the same manner as the process 400 of Fig. 4.

[0087] In some arrangements, the level Q3 may be set to a zero level, i.e., the light illumination level is set for the light to turn off rather than dimmed to a decreased illumination level. Alternatively, the illumination level may be set to a default level, e.g., 50% of maximum illumination. In other arrangements, the illumination level may be set to Q3 for certain portion(s) of the off time of the night, and the light switched off for other portions of the off time.

[0088] Fig. 9A. shows an example in which, at the summer solstice, sunset occurs at 8:29pm, sunrise occurs at 5:58am, and accordingly the durati on D of the night is approximatel 9 hours and 30 minutes. In contrast, at the winter solstice, sunset occurs at 5: 14pm, sunrise occurs at 7.24am, and accordingly the duration /) of the night is approximately 14 hours and 12 minutes. [0089] Fig. 98 shows performance of the ALSS arrangemen described in relation to Fig. 8 which switches on the light 10 to illumination level Ql at sunset for a first proportion of the duration D of the night, being preset at 50% of the night in. the present example. The first proportion may be set by the user as desired. Thereafter, the light illumination level is modified to the level 03 for a second proportion of the duration D of the night, being preset at 35% of the night in the example. The second proportion of the duration of the night may be set by the user as desired. The illumination level of the light 1 10 is modified to 02 for the remainder of the duratio D of the night, being 15% of the night in the example.

[0090] Since D varies with the season, at the summer solstice the light is switched on at level Ql at 8:29pm and modified to Q3 at 1:15am, thus being on at Ql for 4 hours and 45 minutes (50% of the duration D of the night which is approximately 9 hours and 30 minutes). The light illumination level is then modified to the illumination level Q3 at 1: 15 am until 4:35am, thus being at the level Q3 for approximately 3 hours and 20 minutes which is 35% of the duration D of the night. The light is then on at illumination level Q2 from 4:35am until 6:00am, thus being on for approximatel y 1 hours and 25 minutes which is 15% of the duration /) of the night In all the light is on for approximately 9 hours and 30 minutes, if the level Q3 relates to a dimmed illumination level using less power than normal (full illumination) operation, such reflects an energy saving across 35% of the night in comparison with leaving the light switched on at full illumination level from 8:29pm until 6:00am,

[0091 ] At the winter solstice the light is switched to illumination level Ql at 5:14pm, level Q3 at 12:20am, thus being on at Ql for approximately 7 hours and 6 minutes which is 50% of the duration D of the night (which is approximately 14 hours and 12 minutes). The light is then on at the illumination level 0 from 1.2:20am until 5:20am, thus being dimmed for 5 hours which is 35% of the duration D of the night. The light is then on at the illumination level Q2 from 5:20am unti l 7:26am, thus being on for 2 hours and 6 minutes which is 15% of the duration D of the night, in all the light is on at the Ql and Q2 levels for 9 hours and 12 minutes. Such may reflect an energy saving across 35% of the night if the light 1 10 has a dimmed illumination level at the level 03 in comparison with leaving the light .1 10 switched on at full illumination from 5: 14pm until 7:26am. Industrial Applicability

[0091] The arrangements described are applicabie to the power conditioning industries and particularly for energy saving lighting arrangements.

[0093] The foregoing describes only some embodiments of the present invention, and modifications and/or changes can be made thereto without departing from the scope and spirit of the invention, the embodiments being illustrative and not restrictive.

[0094] In the context of this specification, the word "comprising" means "including principally but not necessarily solely" or "having" or "including", and not "consisting only of. Variations of the word "comprising", such as "comprise" and "comprises" have correspondingly varied meanings.