SYSTEM FOR CONTROLLING OPERATIONS OF ROOF LIGHTS INSTALLED IN INDUSTRIES
FIELD OF INVENTION:

[001] The present subject matter described herein, relates to a system for controlling operations of roof lights in industries.
BACKGROUND AND PRIOR ART:
[002] Generally, all industry premises are installed with a number of roof lights for providing illumination during night time operation. The number of roof lights are different capacities depending upon the height of installation and ambient illumination levels required at working places. The number of roof lights are to be operated piece-wise or centrally depending upon the scale of the industry. However, in the both cases the number of roof lights are operated manually. An operator switches ON manually for further working during night time when the ambient illumination levels are going down around the industry. In most cases, the number of roof lights are grouped together in individual bays and a separate control is provided for each group. The operator checks around the industry floor and switch ON each group manually, so it can be a time-consuming and tiring task if the number of roof lights is more. More number of bays are formed in the industry, and more number of roof lights are installed in the bays in such a way difficulty to operate the roof lights by the operator. The above-mentioned problem can be overcome by centralized control of the lights. In this all the individual groups in the bays are interconnected to a single switch. The operator can switch ON all the lights from a single location in such centralized connection.
[003] In the prior arts, control of roof lights is achieved by a timer. All the roof lights are integrated into a single timer. The timer has two set points such that the set points consist of switching ON and switching OFF. However, the prior arts do not allow controlling the roof lights while the sunset time varies with a specific season during the year. The switches ON the roof lights at a single time during the entire year, also operates all the roof lights during holidays (including Sundays) as no separate provision can be made for control during holidays. To avoid this unwanted operation, the operator frequently checks the sunset times and holidays and changes the ON/OFF times of the timer. Also, there is no facility to provide minimal illumination when the work ends during the night shift.
[004] US granted patent US 5,160,853 A to “Tim Simon” and “Lee Tong” for the invention of an automatic light switch with a programmable timer for turning a light ON and OFF using stored geographical, calendar, and daylight savings information. The invention is silent about overcast day times where visibility is poor and no means to switch ON the lights under these circumstances.
OBJECTS OF THE INVENTION:
[005] The principal objective of the present invention is to provide a system for controlling operations of roof lights installed in industries.
[006] Another object of the present subject matter is to ensure operations of the roof lights with varying sunset times throughout the year without manual intervention.
[007] Another object of the present subject matter is to ensure operations of minimal lights for basic illumination of the industry when the production activities ends during the night shift.
[008] Another object of the present subject matter is to operate very few roof lights for basic illumination during industry holidays such that the dates of holidays are pre-programmed for at least ten years.
[009] Yet another object of the present invention is to ensure that the roof lights are automatically operated depending on the required illumination levels even during daytime, reacting to environmental changes like cloud cover, rain etc. which lower visibility.
SUMMARY OF THE INVENTION:
[0010] The subject matter disclosed herein relates to a system for controlling operations of roof lights installed in industries or factory shops. The system has at least one ambient light sensor for constantly monitoring ambient lighting levels placed at different places in the industry. A control unit is coupled with the at least one ambient light sensor and the interacting display device, such that the control unit (1) comprises a communication module coupled with the interacting display device to display real time status and receive inputs for updating in control operations. An input analog module of the control unit is coupled with the at least one ambient light sensor to receive inputs and send the received inputs to at least three digital output modules to process the received analog signals. Each digital output module from at least three digital output modules is connected with relays and send the processed signals to the connected relays for activation of operation circuits.
[0011] In another embodiment, the present subject matter disclosed herein relates to a method for controlling operations of roof lights installed in industries. The method involves determining ambient light conditions in the industry by at least one ambient light sensor. If Auto mode is selected by a control unit, upon affirmative output of the auto mode, current date is compared with prestored calendar having holiday dates and activating one of the relays (R3) when the current date is holiday date. The relays (R2 and R3) are activated when real time of the control unit matches with set time 1. The relay (R1) is activated, and the relay (R2) is closed, when the real time of the control unit matches with set time 2. Further, the relays (R1 and R2) are closed when the real time of the control unit matches with set time 3.
[0012] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0014] Fig. 1 illustrates a circuit diagram of a control unit along with ambient light sensors, a human-machine interface and a plurality of actuating relays, in accordance with an embodiment of the present subject matter;
[0015] Fig. 2 illustrates a process flow diagram of the system encompassing 12-hours, 7-hours, and holiday circuits, in accordance with an embodiment of the present subject matter;
[0016] Fig. 3 illustrates a process flow diagram of a lux measurement subroutine, in accordance with an embodiment of the present subject matter;
[0017] Fig. 4 illustrates a circuit diagram of operation of the system in a small-scale integration of roof lights, in accordance with an embodiment of the present subject matter;
[0018] Fig. 5 illustrates a circuit diagram of field-side connection of the system in a small-scale integration of roof lights, in accordance with an embodiment of the present subject matter;
[0019] Fig. 6 illustrates a circuit diagram of operation of the system in a large-scale integration with control of over the roof lights, in accordance with an embodiment of the present subject matter;
[0020] Fig. 7 illustrates a circuit diagram of composition and operation of the on-field individual lighting distribution boxes (LDBs), in accordance with an embodiment of the present subject matter;
[0021] Fig. 8 illustrates a circuit diagram of the roof lights wiring configurations for the 12-hours, 7-hours, and holiday circuits, in accordance with an embodiment of the present subject matter; and
[0022] Fig. 9 illustrates various parameters and options displayed on the custom-made, touch-operated human-machine interface screen, in accordance with an embodiment of the present subject.
[0023] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0024] The subject matter disclosed herein relates to a system for controlling operations of roof lights installed in industries or factory shops. The system has at least one ambient light sensor for constantly monitoring ambient lighting levels placed at different places in the industry. Further, the system includes a control unit which is coupled with the at least one ambient light sensor and the interacting display device. The control unit comprises a communication module that is coupled with the interacting display device to display real time status and receive inputs for updating in control operations. Further, the control unit has an input analog module that is coupled with the at least one ambient light sensor to receive inputs and send the received inputs to at least three digital output modules to process the received analog signals. Each digital output module from at least three digital output modules is connected with relays and send the processed signals to the connected relays for activation of operation circuits, such as 12 hours operation circuit, 7 hours operation circuit, and holiday operation circuit.
[0025] In another embodiment of the invention relates to a method for controlling operations of roof lights installed in industries. The method involves determining ambient light conditions in the industry by at least one ambient light sensor. If Auto mode is selected by a control unit, upon affirmative output of the auto mode, current date is compared with pre-stored calendar having holiday dates and activating one of the relays (R3) when the current date is holiday date. The relays (R2 and R3) are activated when real time of the control unit matches with set time 1. The relay (R1) is activated, and the relay (R2) is closed, when the real time of the control unit matches with set time 2. Further, the relays (R1 and R2) are closed when the real time of the control unit matches with set time 3.
[0026] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0027] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0028] FIG. 1 illustrates a circuit diagram of the control unit (1) along with at least one ambient light sensor (3), an interacting display device (2), and the plurality of actuating relays (R1, R2, R3) of the system. The system has a control unit (1) in the form of Programmable Logic Controller (PLC), an interacting display device (2) in the form of a 12-inch touchscreen (2), at least one ambient light sensor (3), and three circuit actuators in the form of plurality of relays (R1, R2, R3).
[0029] Upon receiving the command from the PLC (1), the relay R1 activates the 12-hours circuit. Similarly, the relays (R2, R3) active the 7-hours circuit and holiday circuit respectively. The ambient light sensor (3) (photo sensor) constantly monitors the ambient lighting levels inside the industries in the form of LUX levels and sends the values to the PLC (1). The PLC (1) comprises a power supply module (7), a communication module (8), an analog input module (9), and digital output modules (10, 11, 12). The power supply module (7) provides 24V DC power supply for the operation of the PLC (1). The communication module (8) interacts with the touchscreen (2) to continuously update current operation status and receive inputs from the end-user/operator. The communication module (8) uses a popular communication protocol known as PROFIBUSTM. The analog input module (9) receives analog inputs from the light sensor (3) placed at various strategic locations in the industry and sends the values to the control program of the PLC (1).
[0030] The input analog module (9) is coupled with the at least one ambient light sensor (3) to receive inputs and send the received inputs to at least three digital output modules (10, 11, 12) such that the at least three digital output modules (10, 11, 12) process the received analog signals. Each digital output module (10) from at least three digital output modules (10, 11, 12) is connected with relay (R1, R2, R3) and send the processed signals to the connected relays for activation of 12-hours, 7-hours and holiday circuits respectively.
[0031] The power supply module (7) is configured to provide low-voltage 24V DC power supply for operation of the PLC (1) in small-scale integration, in addition, to provide high-voltage 230V AC power supply for operation of the PLC (1) in large-scale integration.
[0032] The analog input module (9) of the PLC (1) is configured to receive analog inputs from the at least one ambient light sensor (3) and to send the values to the PLC (1). The analog input module (9) process the received analog inputs from the at least one ambient light sensor (3) and send signal to the at least three digital output modules (10, 11, 12) to activate the relay (R2) for activation of 7 hours circuit when the ambient light is less than a predefined threshold value.
[0033] The PLC (1) is configured to determine whether AUTO mode is selected; to activate the holiday circuit via the relay (R3) when current date matches with holiday date, to activate the relay (R1) and (R2) when real time of the PLC (1) matches with set time 1, and activate the relay (R1) and closes the relay (R2) when real time of the control unit (1) matches with set time 2, further, close both the relays (R1 and R2) when real time of the control unit (1) matches with set time 3.
[0034] FIG. 2 illustrates a process flow diagram of the lighting management system encompassing the 12-hours, 7-hours, and holiday circuits. The system constantly keeps checking for the values of ambient lighting levels via the light sensor (3) placed at various strategic locations in the industry. If the ambient light level drops due to earlier sunset or cloudy conditions, the system activates a LUX subroutine (13). If the output values of LUX subroutine (13) is less than 10% of the ambient, the system switches ON the 7-hours circuit till the ambient light level improves or any of the set points are reached. If the ambient light levels are normal, the system checks the operation mode which can be either AUTO or MANUAL. If AUTO mode is selected by the operator, the current date is checked. If the current date falls on any of the designated holidays, the holiday circuit is switched ON via the relay (R3). AUTO mode operates with 3 set points, such as first to switch ON all the roof lights (both 12-hours and 7-hours circuits), second to switch OFF 12-hours circuit and operate only the 7-hours circuit, and third to switch OFF all the lights at sunrise. The set point 1 is usually the time around sunset when the ambient light level drops. The set point 2 is the time when the shift operations end during night time. The system constantly keeps checking the real time upon confirming that the day is not a holiday. If the set points 1 and 2 are reached, the system activates the 12-hours and 7-hours circuits via the relays (R1, R2). Unless MANUAL mode is specifically selected, the system operates in AUTO mode by default after performing the necessary checks. If MANUAL mode is selected, the system requires the operator to manually set OFF-delay time thus facilitating the operation of roof lights even after the set point 2 has been reached.
[0035] FIG. 3 illustrates a process flow diagram of the LUX measurement subroutine (13). The ambient light sensor (3) is placed at least two or more strategic locations in the industry. The LUX measurement subroutine (13) constantly reads LUX values from the light sensors (3). When the LUX levels read by reach the same value, the LUX measurement subroutine (13) sends the output LUX value to a main program of the digital output module (12) for decision-making.
[0036] FIG. 4 illustrates a circuit diagram of the operation of the system in a small-scale integration of roof lights. When the industry has less number of roof lights and small surface area, the system is integrated on a 24V DC control supply. The system is operated on low voltages as there will not be any drop in control voltages over short distances. Here, the PLC (1) is powered by a 24V DC supply through the power supply module (7) of the PLC (1). The 24V DC power supply is generated from an external source and fed to a power bus (14) of the PLC (1). The system also has three digital outputs such as Q0.0 (15), Q0.1 (16), and Q0.2 (17). The digital outputs activate the three circuits (12-hours, 7-hours and holiday circuits) through the 24V DC relays K1 (18), K2 (19), and K3 (20).
[0037] Ground connection for the system is fed from a COM module (21) in the PLC (1). The ground connection reaches the relays K1, K2, and K3 through a ground bus (22) from the COM module (21). The relays K1 (18), K2 (19), and K3 (20) are electromagnetically operated switches (23) which close the power connection upon activation. A relatively small electric current turns ON or OFF much larger electric current. When the PLC (1) activates the designated circuit via either Q0.0 (15), Q0.1 (16), or Q0.2 (17), the 24V DC power supply from the power bus (14) reaches the K1 (18), K2 (19), or K3 (20) respectively. The relay K1 (18) comprises an electromagnet (24) (a coil of wire that becomes a temporary magnet when electricity flows through it), upon getting magnetized, the electromagnet (24) closes the switch (25) which sends the supply further towards the roof lights. The relays K1 (18), K2 (19), or K3 (20) comprise electromagnets (24, 26, and 27) and switches (25, 28, and 29) which operate the 12-hours, 7-hours, and holiday circuits respectively. The 24V DC power supply via the power bus (14) from the power supply module (7) reaches the all relays K1 (18), K2 (19), and K3 (20).
[0038] FIG. 5 illustrates a circuit diagram of the field-side connection of the system in a small-scale integration of the roof lights. The group of lighting distribution boxes (LDBs) (30) are placed around the industry to connect the roof lights. The LDBs (30) are uniformly distributed throughout the industry. In the industry with ß bays, ? LDBs (30) are installed in each bay to cover all the roof lights in the bay. The 24V DC power bus (14) has no drops due to short distances and fewer number of roof lights. When the relay K1 (18) is activated by the PLC (1) to switch ON the 12-hours circuit, the electromagnetic coil (24) inside the relay closes the switch (25). This causes the 24V DC power supply to flow the LDBs (30) through dedicated cables (31). The LDBs (30) receive power in a 12-hours circuit cable line (31) and the designated lights are switched ON for 12-hours from the first set point. Similarly, when the relay K2 (19) switches ON the 7-hours circuit, the LDBs receive power from a dedicated 7-hours cable line (32). At the first set point, both relays K1 (18) and K2 (19) are activated. At the second set point, only the 12-hours cable line (31) is operated and the 7-hours cable line (32) is switched OFF. Similarly, during holidays, the relay K3 (20) is activated by the PLC (1). The 24V DC power supply is fed to the LDBs (30) through the holiday cable line (33) and the designated roof lights are switched ON.
[0039] FIG. 6 illustrates a circuit diagram of operation of the system in a large-scale integration with control of over the roof lights using 230V AC power supply. The PLC (1), the analog input module (9) and the digital output modules (10, 11, and 12) function on 24V DC power supply. As such, the operation on the PLC (1) side is similar to the operation described in FIG. 4. The relays R1 (4), R2 (5), and R3 (6) function on the 24V DC power supply. The relays R1 (4), R2 (5), and R3 (6) are also electromagnetically operated switches (23) which close the power connection upon activation. The relays R1 (4), R2 (5), and R3 (6) comprise electromagnets (34, 35, and 36) which close the switches (37, 38, and 39) when the switches get magnetized. When the switches (37, 38, and 39) are closed, the switches (37, 38, and 39) send the 24V DC power supply further towards the relays K1 (18), K2 (19), or K3 (20). The relays K1 (18), K2 (19), and K3 (20) are operated on 230V AC power supply. The 24V DC power supply from the relays R1 (4), R2 (5), and R3 (6) magnetizes the electromagnets (24, 26, and 27) which close the switches (25, 28, and 29). Closing of the switches send the 230V AC power supply to the industry. The relays R1 (4), R2 (5), and R3 (6) and subsequently, the relays K1 (18), K2 (19), or K3 (20) operate the 12-hours, 7-hours, and holiday circuits respectively. The system operates with 56 LDBs (30) which control over the roof lights in the industry. The industry is divided into seven bays with separate controls provided for the three circuits. Each bay has eight LDBs (30), such that each bay is provided with three more relays K4 (41), K5 (42), K6 (43), K7 (44), K8 (45), K9 (46), and K10 (47) which operate 12-hours circuit in the seven bays. Similarly, the relays K11 (48), K12 (49), K13 (50), K14 (51), K15 (52), K16 (53), and K17 (54) operate the 7-hours circuit and relays K18 (55), K19 (56), K20 (57), K21 (58), K22 (59), K23 (60), and K24 (61) operate the holiday circuit. All the relays operate on 230V AC power supply. When the relay R1 (4) is switched ON by the PLC (1) to operate the 12-hours circuit, the relay K1 (18) gets switched ON. The relay K1 (18) switches ON all the 12-hours relays, the relays K4 to K10 (41 to 47), in all seven bays. The relays K4 to K10 (41 to 47) send the 230V AC power supply to relays inside the LDBs (30) for switching ON the 12-hours circuit via K1B-1 to K1B-7 control signals. Similarly, the relays K11 to K17 (48 to 54) operate the 7-hours circuit via K2B-1 to K2B-7 control signals and the relays K18 to K24 (55 to 61) operate the holiday circuit via K3B-1 to K3B-7 control signals.
[0040] FIG. 7 illustrates a circuit diagram of the composition and operation of the on-field individual LDBs (30). Each LDB (30) comprises of a metallic box housing having three 230V AC contactors (62, 63, and 64) and 21 circuit breakers or MCBs (65) each of which operate the individual roof lights connected to the LDB (30). The contactors (62, 63, and 64) are switches, which operate on receiving a control signal. Upon receiving K1B-1 control signal, the contactor (66) gets switched ON. The contactors (62, 63, and 64) send the power supply forward to the MCBs (65), such that each MCB (65) operates the individual roof lights. The 12-hours circuit lights connected to the corresponding MCBs (65) get switched ON. Similarly, K2B-1 (7-hours) and K3B-1 (holiday) control signals are received by the corresponding contactors (63 and 64) respectively.
[0041] FIG. 8 illustrates a circuit diagram of the roof light wiring configurations for the 12-hours, 7-hours, and holiday circuits. The individual MCBs (65) operate a single roof light (67). Lights L1 to L6 are connected to the 12-hours circuit, lights L7 to L18 form the 7-hours circuit, and lights L19 to L21 are the holiday circuit lights. The 21 lights (L1 to L21) form a single LDB (30), and eight LDBs (30) connect all the roof light of a single bay. Finally, the 56 LDBs (30) form entire lighting network of the industry with over thousand roof lights.
[0042] FIG. 9 illustrates the various parameters and options displayed on the custom-made, touch-operated human-machine interface screen (2). The 12-inch touchscreen (12) displays the custom-made user interface (68) that shows the mode of operation (AUTO or MANUAL), ON/OFF condition of the light sensor (3), current time, day and date, set points 1, 2, and 3 (switching ON all lights at sunset, switching OFF the 7-hours lights while operating the 12-hours lights, and switching OFF all the lights at sunrise respectively), and the current illumination levels sensed by the light sensors (3).
[0043] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0044] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.
[0045] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

We claim:

1. A system (100) for controlling operations of roof lights installed in industries, the system (100) comprising:
at least one ambient light sensor (3) for constantly monitoring ambient lighting levels placed at different places in the industry area;
an interacting display device (2) displays information; and
a control unit (1) coupled with the at least one ambient light sensor (3) and the interacting display device (2), the control unit (1) comprises:
a communication module (8) coupled with the interacting display device (2) to display real time status and receive inputs for updating in control operations;
an input analog module (9) coupled with the at least one ambient light sensor (3) to receive inputs and send the received inputs to at least three digital output modules (10, 11, 12); the at least three digital output modules (10, 11, 12) process the received analog signals;
each digital output module (10) from at least three digital output modules (10, 11, 12) is connected with relay (R1, R2, R3) and send the processed signals to the connected relays for activation of operation circuits.

2. The system (100) as claimed in claim 1, wherein the control unit (1) further comprises a power supply module (7) to supply power to the control unit (1) and the relays (R1, R2, R3).

3. The system (100) as claimed in claim 2, wherein the power supply module (7) is configured to provide low-voltage 24V DC power supply for operation of the control unit (1) in small-scale integration, in addition, to provide high-voltage 230V AC power supply for operation of the control unit (1) in large-scale integration.
4. analog input module (9) is configured to receive analog inputs from the at least one ambient light sensor (3) and to send the values to the control unit (1).

5. The system (100) as claimed in claim 1, wherein the analog input module (9) process the received analog inputs from the at least one ambient light sensor (3) and send signal to the at least three digital output modules (10, 11, 12) to activate the relay (R2) for activation of 7 hour circuit when the ambient light is less than a predefined threshold value.

6. The system (100) as claimed in claim 1, wherein the at least one ambient sensor (3) is placed at different locations in the industry.

7. The system (100) as claimed in claim 1, wherein the interacting display device (2) is configured to update the control unit (1).

8. The system (100) as claimed in claim 1, wherein the control unit (1) is configured to:
determine whether auto mode is selected;
activate the holiday circuit via the relay (R3) when current date matches with holiday date;
activate the relay (R1) and (R2) when real time of the control unit (1) matches with set time 1;
activate the relay (R1) and closes the relay (R2) when real time of the control unit (1) matches with set time 2; and
closes both the relays (R1 and R2) when real time of the control unit (1) matches with set time 3.

9. A method for controlling operations of roof lights installed in industries, the method comprising the steps of:
determining, by at least one ambient light sensor (3), ambient light conditions in the industry;
checking, by a control unit (1), whether Auto mode is selected;
upon affirmative output of the auto mode, comparing current date with prestored calendar having holiday dates and activating relay (R3) when current date is holiday date;
activating relay (R2 and R3) when real time of the control unit (1) matches with set time 1;
activating relay (R1) and closing the relay (R2) when real time of the control unit (1) matches with set time 2; and
closing the relay (R1 and R2) when real time of the control unit (1) matches with set time 3.

10. The method as claimed in the claim 9, wherein the determining further comprises:
comparing the ambient light with predefined threshold LUX value; and
activating the relay (R2) when the ambient light is less than the predefined threshold LUX value.