FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
“SEQUENTIAL LED BLINKER DRAWING CONSTANT CURRENT FROM SOURCE”
MINDA RINDER PVT. LTD., of Gat No 148, Mahalunge Ingale, Off Chakan Talegaon Road, Taluka- Khed, Dist. –Pune, Maharashtra 410501, India
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION:
[0001] The present invention relates to field of automobiles. More particularly, the present
invention relates to a system and method for providing sequential blinking of LED and drawing constant current.
BACKGROUND OF THE INVENTION:
[0002] Blinkers are mounted on left and right side of the automobiles for guiding about the
traveling direction through flashing. With the help of blinkers vehicle operator may notify other drivers about his/her intention with respect to the vehicle. These blinkers are therefore critically important in preventing accidents.
[0003] Generally, blinkers use LEDs arranged in a series combination and follows a
sequence while blinking, therefore, termed as sequential LED blinkers as well. In sequential LED blinker, each string comprises one or more LEDs connected in series which turn ‘ON’ in a sequential manner. Each LED consume separate current until the whole sequence gets complete. Accordingly, as the number of strings increases, current consumption varies from one string to another string. Due to this arrangement, blinker draws different amount of current from source, which leads to increase power consumption in such circuits.
[0004] Usually a body control unit (BCU) of the vehicle monitors current drawn by each
LED in a string and generates a fault signal if any of the string blows OFF. However, in currently available Sequential blinkers, current consumption increases with blinking of every next LED in Turn ‘ON ‘sequence. As a result, the BCU gets different current with respect to LED turn ‘ON’ sequence and may generate incorrect fault signal if any of the LED draws current below the threshold even if the LED is not blown OFF. In other words, the BCU may generate a fault signal even if the blinker is not blown OFF due to different current drawn by each LED.
[0005] Thus, there is a need in the art for a sequential circuit of the LED blinker which overcome the above-mentioned problems. The present disclosure is directed to provide solution to the above and other problems existing in the prior art.

SUMMARY OF THE INVENTION:
[0006] Before the present system and method is described, it is to be understood that this
disclosure is not limited to the particular systems, and methodologies described, as there can be multiple possible embodiments of the present disclosure which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope of the present disclosure.
[0007] In an aspect, the present disclosure describes a sequential blinker system. The
system comprising a plurality of strings of series connected LEDs, at least one diode, a constant current unit, a first switching unit, a plurality of second switching units and a controller. The at least one diode is connected in shunt with said plurality of strings of series connected LEDs. The constant current circuit have at least two channels, wherein first channel is connected to anode terminal of said at least one diode and second channel is connected to anode terminal of said plurality of strings of series connected LEDs. The controller connected to the first switching unit and the plurality of second switching units, wherein said controller is configured to: activate the first switching unit, connected to cathode terminal of said at least one diode, to provide constant current flow in first string of said plurality of strings of series connected LED, and deactivate said first switching unit, once the constant current is provided in subsequent string of series connected LED; and activate at least one of a plurality of second switching units, connected to cathode terminal of LED of said plurality of strings of series-connected LEDs, to illuminate string of series-connected LEDs.
[0008] In another aspect of the present disclosure, as disclosed, only one of said second
switching units is activated for string of series connected LEDs, at any given instant of time.
[0009] In yet another aspect of the present disclosure, as disclosed, a body control unit
(BCU) configured to send a signal to said constant current unit and said controller; and monitor current drawn through the plurality of strings of series connected LEDs at a predefined period.

[00010] In still another aspect of the present disclosure, as disclosed, BCU configured to
send a signal to said controller, if the current drawn from any of the strings of series connected LED is below than a predefined threshold.
[00011] In another aspect of the present disclosure, as disclosed, the controller, upon
determination that the current drawn by the string of series connected LED is below the threshold, is configured to send a signal to increase the frequency of illumination of LED present in string of series connected LED.
[00012] In still another aspect of the present disclosure, as disclosed, the strings of series
connected LEDs are connected in parallel.
[00013] In an aspect, the present disclosure describes a method for sequential blinking. The
method, as discloses comprising activating a first switching unit connected to cathode terminal of at least one diode to provide constant current flow in first string of a plurality of strings of series connected LEDs. The method further comprises deactivating said first switching unit connected to cathode terminal of said at least one diode once the constant current is provided in subsequent string of series connected LED and activating at least one of a plurality of second switching units, connected to cathode terminal of LED of said plurality of strings of series-connected LEDs, to illuminate string of series-connected LEDs.
[00014] In another aspect of the present disclosure, as disclosed, the method comprises
activating only one of said second switching units for the string of series connected LEDs at any given instant of time.
[00015] In yet another aspect of the present disclosure, as disclosed, the method comprises
monitoring current drawn through the plurality of strings of series connected LEDs at a predefined period.
[00016] In still another aspect of the present disclosure, as disclosed, the method comprises
sending a signal to a controller if the current drawn from any of the strings of series connected LED is below than a predefined threshold.

[00017] In another aspect of the present disclosure, as disclosed, the method comprises
sending a signal to increase the frequency of illumination of LED present in string of series connected LED if the current drawn by the string of series connected LEDs falls below the threshold.
[00018] In the above paragraphs, the most important features of the invention have been
outlined, in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better understood and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important therefore that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of the invention.
OBJECTS OF THE INVENTION:
[00019] The main object, of the present invention is to provide a sequential circuit of the
LED blinker which draws constant current throughout the process.
[00020] Another main object, of the present invention, is to provide accurate detection of
fault in the blinker circuit and change the frequency of neighbouring LED for blinking accordingly.
BRIEF DESCRIPTION OF DRAWINGS:
[00021] Further aspects and advantages of the present invention will be readily understood
from the following detailed description with reference to the accompanying drawings, where like reference numerals refer to identical or functionally similar elements throughout the separate views. The figures together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the aspects and explain various principles and advantages, in accordance with the present invention wherein:

[00022] Figure 1 illustrates an exemplary block diagram of a Sequential blinker system
according to an embodiment of the present invention.
[00023] Figure 2 illustrates a circuit diagram for presenting the connection details of various
components according to an embodiment of the present invention.
[00024] Figure 3 illustrates a circuit diagram for presenting the connection details of
exemplary embodiment according to the present invention.
[00025] Figure 4 illustrates a flowchart diagram illustrating a method for operation of
sequential blinking, according to an embodiment of present invention.
[00026] Figure 5 illustrates flowchart diagram illustrating the conditions of fault and process
to overcome the same according to an embodiment of present invention.
[00027] While the invention is susceptible to various modifications and alternative forms,
specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the present invention.
[00028] Skilled artisans will appreciate that elements in the drawings are illustrated for
simplicity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of aspects of the present invention.
DETAILED DESCRIPTION OF DRAWINGS:

[00029] The present invention will be described herein with reference to the accompanying
drawings. In the following description, well known functions or constructions are not described in detail since they would obscure the description with unnecessary detail.
[00030] In the present document, the word "exemplary" is used herein to mean "serving as
an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
[00031] While the disclosure is susceptible to various modifications and alternative forms,
specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
[00032] The terms “comprises”, “comprising”, “include(s)”, or any other variations thereof,
are intended to cover a non-exclusive inclusion, such that a setup, arrangement, unit, system or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or arrangement or unit or system or method. In other words, one or more elements in a system or apparatus or unit or arrangement proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus or unit or arrangement.
[00033] The present invention relates to the system and method for accurately determining
the fault in the sequential blinker system by way of maintaining constant current through all the strings connected through the constant current LED driver.
[00034] Figure 1 illustrates the schematic diagram of a Sequential blinker system according
to an aspect of the present disclosure. As shown in fig. 1, the block (100) comprises of a constant current LED driver (101) which is connected to a body control unit (BCU) of a vehicle (not shown

in the figure). A microcontroller (103) is connected to the constant current LED driver (101) and BCU. The Microcontroller (103) get supply with the help of power supply unit (not shown in figure). The Body Control Unit (BCU) of the vehicle provide pulse ON signal to the constant current LED driver (101) and the microcontroller (103). This pulse ON signal informs the constant current LED driver (101) and the microcontroller (103) when to switch ON the blinker.
[00035] The output of constant current LED driver (101) is passed to multiple strings
through multiple channels. In an exemplary embodiment, there are two channels provided from the constant current LED driver (101). Channels 1 & 2 are connected through different strings. In an embodiment, block1 (105) contains a combination of diodes and resistors to keep the consumption of current in the circuit constant whereas block2 (107) contains multiple LEDs connected in series fashion for blinking. For example, block 1 (105) may consist of combination of various diodes D1, D2…DN and Various resistors R1… RN. In an exemplary embodiment, the diodes (D1, D2…DN ) can be Zener diode or p-n junction diode. Further, both the blocks 1 and 2 are connected to the microcontroller (103) through a switching circuit (109). The switching circuit (109) helps in switching the components associated in block1 and block 2.
[00036] Figure 2 illustrates the circuit diagram for presenting the connection details of
various components according to an embodiment of the present invention. As described in figure 1, there can be multiple channels associated with the constant current LED driver 201. In an exemplary embodiment, there are three channels associated with constant current LED driver 201. Different channels are used for connecting the strings of diodes and resistor combinations to the strings having combination of LEDs. The switching circuit is represented by npn transistors in figure 2. In another embodiments, there can be other switching elements used for performing the switching action such as FET, MOSFET, pnp transistor etc. The microcontroller (203) is connected for providing inputs to activate/deactivate the switching circuits (e.g transistors) which in turn are responsible for the LED blinking. In other words, the microcontroller (203) or the control unit sends signal for turning on or off of the switching circuit to enable the constant current flow in the circuit. Further, based on the activation and deactivation of the switching circuit (e.g. transistor), a signal is passed to the corresponding LEDs in various strings. As shown in figure 2, there can be n strings present in the circuit having combination of diodes and resistors connected in parallel

with each other. Similarly, there can be n number of strings associated with different channels having series combination of LEDs. A person skilled in the electronics/circuit design, can understand the manner in which combination of strings of diode & resistor and combination of LEDs is arranged by referring the figures 2 and 3 (explained below).
[00037] Figure 3 represents an exemplary embodiment of the present invention for
presenting the sequential blinker system. The system (300) further comprises at least one first string (305) (i.e. string1) which is connected to the constant current LED driver (301) and the microcontroller (303). The system (300) may comprises of more than one such strings (305a…305n) containing multiple diodes and resistor combination but for the illustration and explanation purpose, only one such string (i.e string 1, 305) is described herein. In particular, one end of string 1 (305) ) takes input from the constant current LED driver (301) and the other end is connected to switching unit or transistor Q7 through R1. Transistor Q7 is also connected to the microcontroller (303) via resistor R6 and transistor Q7. Mainly, transistor Q7 which is used as switching element is connected to string1 (305) for receiving the signal from microcontroller (303). In particular, when the transistor Q7 is in active state, it behaves as a short circuit and connects the string1 (305) to ground. The system (300) further comprises of at least one LED string (307A, 307B….307N) which is connected to the constant current LED driver (303) and the microcontroller (305). In an embodiment, the system (300) may comprise of two LED strings i.e. string 2 (107a) and string 3 (107b), as shown in fig. 1. System (300) may comprise more than two LED strings (307A, 307B….307N). At least one LED string (307A, 307B….307N) may comprise of more than one LEDs. In an embodiment, string 2 (307a) may comprise of three LEDs i.e. LED1, LED2 and LED3, which are connected in series. Similarly, string 3 (307b) may comprise of three LEDs i.e. LED4, LED5 and LED6, which are connected in series. It should be noted that although three LEDs have been used in each string 2 and 3, more LEDs can also be used in the strings 2 and 3. As shown in fig. 3, LED1 to LED 6 are connected to the microcontroller (303) via transistors Q1 to Q6 respectively. It can be noted that transistor Q1 to Q6 are connected for turning on/off of LEDs i.e. LED1 to LED6.
[00038] As shown in fig. 3, in an embodiment, string 1 (305), string 2 (307a) and string 3
(307b) are parallelly connected. Body control unit (BCU) provides pulse ON signal to the constant

current LED Driver (301) and the microcontroller (303). After receiving signal from BCU, constant current LED Driver (301) provides constant current to two channels i.e channel 1 (having strings 1 and 3 connected to it) and channel 2 (having string 2 connected to it). In another embodiment, there may be more than 2 channels available for maintaining the constant current supply in each channel. The functioning of string 1 (305), string 2 (307a), string 3 (307b) and microcontroller (303) for switching transistors Q1 to Q7, is described below:
[00039] Upon receiving the pulse ON signal from the BCU, the constant current driver (301)
provides input to the channel 1 and channel 2 strings. Further, at the initial level, the microcontroller (303) sends a signal to transistor Q7 and Q1 simultaneously. Once, the signal from the microcontroller (303) is received by the transistor Q7, the current flowing through the diodes D1, D2…DN is grounded. At the same time, another signal from the microcontroller (303) is received at transistor Q1 which takes the transistor Q1 into active state. Activation of transistor Q1 leads the LED1 in turn on state while keeping the other LED’s in turn off state. In this way, both the channels i.e channel 1 and channel 2 draw equal amount of current. After turning ON the LED1, the transistor Q1 gets deactivation signal from the microcontroller (303) and transistor Q2 gets activation signal. Accordingly, the LED2 turns on along with LED1 while the other LEDs remain turn off on activation of transistor Q2. Similarly, after turning ON LED1 and LED2, transistor Q2 gets deactivation signal from the microcontroller (303) and transistor Q3 gets activation signal. On activation of transistor Q3, LED3 also turns ON along with LED2 and LED1 while the other LEDs of another string remains in turn OFF state. In present embodiment, there are only 3 LEDs present in string 2 (307a), therefore the sequence of LED1, LED2 and LED3 may lead to blinking of the complete string 2 (307a). However, there can be ‘n’ number of LEDs present in any of the strings.
[00040] Similar to string 2(307a), transistors (Q4,Q5 and Q6) ensures sequential turning ON
of LEDs from LED4 to LED 6, by providing constant current to them. For example, Once the LED1,LED2 and LED3 turns on by activation of transistor Q3. The constant current flow is maintained in string 1 (305) and string 2(307a). As soon as the microcontroller (303) provides activation signal to transistor Q4, it also sends a deactivation signal to Q7, because now the transistor Q3 will be responsible for maintaining the constant current in string 2 (307a) and string

3(307b). It can be understood in this way, the role played by the transistor Q7 is now replaced with transistor Q3 for blinking of LEDs present in string 3(307b).
[00041] The process of sequential LED blinking in string 3 (307b) can be understood by
considering the constant current received from the constant current LED driver (101) to LED4. To maintain the constant current in string3 (307b), microcontroller has to deactivate the signal for transistor Q7. At the same time, the microcontroller (303) switches ON the transistor Q4. After turning ON the LED4, the microcontroller (303) switches ON the transistor Q5 and switches OFF transistor Q4. At the same time, the constant current driver (301) provides constant current to LED5 to turn it ‘ON’ along with LED4. In similar way, after turning on the LED5, the microcontroller(303) sends a deactivation signal to Q5 and activation signal to transistor Q6 which is used for turning on LED6 along with LED4 and LED5. Thus, switching OFF transistors Q4 and Q5 and turning on transistor Q6 will lead to maintenance of constant current in string 3 (307b) along with string 2(307a). The same process of maintaining constant current in the system and sequential blinking of LED strings can be repeated for N number of LED strings without disturbing the overall current of the circuit.
[00042] The same process can be understood with the help of flowchart of figure 4 which
represents sequence followed in the complete process. In step 402, the first switching unit which here termed as transistor Q7 is connected to cathode terminal of at least one diode say DN of string 1 (305), is activated to provide constant current flow in string 2 (307a) of a plurality of strings of series connected LEDs (307a , 307b……………..307N ). As explained above, the transistor Q7 will remain activated for initial maintenance of constant current in first string of series connected LEDs i.e string 2 (305). As explained above in exemplary embodiment, Q7 will remain turned on till the time all the LEDs connected in string 2 (307a) gets activation signal. In step 404, the first switching unit i.e.Q7 which is connected to cathode terminal of said at least one diode (DN) is deactivated once the constant current is provided in subsequent string of series connected LED (307b……………..307N). Similar to the process explained above, transistor Q7 gets deactivation signal from the microcontroller (303) once the constant current is maintained in the string 2(307a), as after maintaining the blinking of all the LEDs in string 2(307a), the transistor Q3 associated with string (307a) is responsible for maintaining constant current in both the strings 2 (307a) and string

3 (307b). Thus, in that case, Q7 is no more required for maintaining constant current, accordingly, it will get deactivation signal from the microcontroller (303). In step 406, at least one of a plurality of second switching units (Q1-Q6) which are connected to cathode terminal of LED of plurality of strings of series-connected LEDs is activated to illuminate string of series-connected LEDs. Thus, the mandatory condition for maintaining the constant current in the system is to activate the first switching element i.e. Q7 at initial stage for maintaining constant current in string 1 (305) and one of the second switching elements (Q1 to Q3) corresponding to string 2 (307a). Once all the LEDs starts blinking in string 2(307a), deactivating Q7 if a further string i.e string 3 (307b) starts getting constant current supply through any of second switching element i.e. Q4 to Q6. In this way, the complete process of sequential Led blinking ensures that LED1 should get first ‘ON’ signal then LED2 along with LED1 and likewise up to LED6 (as per the exemplary embodiment).
[00043] The complete flow of the process is presented in table 1 given below:

BCU Signal 'ON'
String 1 String 2 String 3
Q7 Q1 Q2 Q3 Q4 Q5 Q6
ON ON OFF OFF OFF OFF OFF LED 1 LED 2 LED 3 LED 4 LED 5 LED 6 LED 6 LED 6 LED 6 LED 6 LED 6 CASE1
ON OFF ON OFF OFF OFF OFF LED 1 LED 2 LED 3 LED 4 LED 5
CASE2
ON OFF OFF ON OFF OFF OFF LED 1 LED 2 LED 3 LED 4 LED 5
CASE3
OFF OFF OFF ON ON OFF OFF LED 1 LED 2 LED 3 LED 4 LED 5
CASE4
OFF OFF OFF ON OFF ON OFF LED 1 LED 2 LED 3 LED 4 LED 5
CASE5
OFF OFF OFF ON OFF OFF ON LED 1 LED 2 LED 3 LED 4 LED 5
CASE6
T able- 1

[00044] Microcontroller (303) provides activation signal to transistor Q7 and Q1 to maintain
a constant current in strings (305 & 307a) and to turn LED1 ‘ON’ (i.e. case 1). After turning ON the LED1, the constant current driver (301) provides constant current to LED2 to turn it ‘ON’ along with LED1 (i.e. case 2). At the same time, the microcontroller (103) switches ON the transistor Q2 and switches OFF transistor Q1. Similarly, LED3 is turned ‘ON’ along with LED1 and LED2 (i.e. case 3), by providing constant current to LED3 and switching ON transistor Q3 while switching OFF transistors Q1 and Q2. It can be noticed that the microcontroller (303) switches ‘ON’ transistors Q1, Q2 and Q3 with respect to case no 1, 2 and 3 and in each case only one transistor remains ‘ON’ out of Q1 to Q3. This way, only half of the total current passed by constant current LED driver (301) is consumed by string 2 (307a). In order to consume remaining half of the total current, string 1 (305) is provided. In all the three cases, the microcontroller switches ON the transistor Q7 so that the remaining half of the total current can be consumed by string 1 (305). Accordingly, the circuit (300) maintains constant current consumption in all the three cases.
[00045] As explained above in respect of string 2 (307a), string 3 (307b) is similarly turned
ON. For example, the constant current LED driver (301) provides constant current to LED4 to turn it ‘ON’ (i.e. case 4). At the same time, the microcontroller (303) switches ON the transistor Q4. After turning ON the LED4, the constant current driver (301) provides constant current to LED5 to turn it ‘ON’ along with LED4 (i.e. case 5). At the same time, the microcontroller (303) switches ON the transistor Q5 and switches OFF transistor Q4. Similarly, LED6 is turned ‘ON’ along with LED4 and LED5 (i.e. case 6), by providing constant current to LED6 and switching ON transistor Q6 while switching OFF transistors Q4 and Q5. It can be noticed that the microcontroller (303) switches ‘ON’ transistors Q4, Q5 and Q6 with respect to case no 4, 5 and 6 and in each case only one transistor remains ‘ON’ out of Q4 to Q6. This way, only half of the total current passed by constant current LED driver (301) is consumed by string 3 (307b). In order to consume remaining half of the total current, the transistor Q3 remains activated and consume the current. In this case microcontroller (303) gives switching signal to transistor Q3 instead of transistor Q7 and make string 1 (305) ‘OFF’. It should be noted that the switching signal to transistor Q3 keeps string 2 (307a) ‘ON’ with LED1, LED2 and LED3 in ‘ON’ condition and switching signal to transistor Q4,

Q5 or Q6 is required to maintain constant current consumption and illumination of LEDs in all fourth, fifth and sixth case.
[00046] In a practical example, the system (300) is designed for six LEDs and accordingly
two strings are used, the number of strings and/or LEDs can be increased or decreased. For example, for 12V system if 2.5V voltage drop is considered for one LED, then maximum four LEDs can be arranged in single string with series combination and can be individually controlled with constant current for sequential blinker for four LEDs. If 2.5V voltage drop of single LED is considered then in this circuit, one extra LED can be arranged in each string and make sequential blinker of 8 LEDs with same constant current. Hence, depending on the voltage drop of LED, number of LEDs in single string may be changed. Alternatively, for extra LEDs, more number of strings can be connected in parallel combination with individual LED control provision but constant current consumption may be increased. However, even if the number of strings are increased then also each LED can be controlled in the disclosed manner.
[00047] As described, the LED sequential blinker circuit (300) provides constant current to
LEDs and reduces power consumption. Further, as per the industry standards and regulations, if any one of the side blinker fails then other side blinkers should blink by double frequency. All the four blinkers of the vehicle are connected to BCU and current consumption of each blinker is set in the BCU. As soon as a blinker fails then BCU recognizes the fault signal and accordingly, it doubles the frequency signal and all other side blinker blinks by double frequency.
[00048] However, in presently known sequential blinkers, current increases with respect to
LED Turn ‘ON ‘sequence. So, in this case, BCU gets different current with respect to LED turn ‘ON’ sequence and may generate incorrect fault signal if any of the LED draws current below than threshold at starting of the blinker even if the LED is not blown OFF. In other words, the BCU may generate a fault signal even if the blinker is not blown OFF due to different current drawn by each LED. To avoid this problem during sequentially turn ‘ON’ LED condition, BCU should get always constant current so in an embodiment of the present disclosure, one extra String 1 (305) is added in to design to keep constant current consumption. Therefore, BCU will activate double

frequency only when BCU will receive current other than current consumption set for each blinker. In this way, the disclosed system (300) avoids generation of incorrect fault signal.
[00049] Figure 5 represents the flowchart for the operation of blinkers in normal frequency
or double frequency. When the constant current driver (301) receives the pulse ON signal from the BCU, the system (300) may compare the current consumption set for each sequential LED blinker circuit/string with the feedback received from the sequential LED blinker circuit. In case, there is mismatch between the consumption set for each LED blinker string and the actual current consumption of the LED blinker string, then the sequential LED blinker starts blinking with double frequency. For example, the current consumption set for the LED blinker is higher than the feedback related to current consumption received from the LED blinker, in that scenario, the neighbouring LEDs will blink with double frequency. In another scenario, if the current consumption is less than the threshold decided for the LED blinker current consumption, the LED blinker may blink with the normal frequency. Further, the system may also check for the LED open or short circuit based on the feedback received from the LED blinker strings e.g. string 2(307a), string 3(307b) and so on. In case, there is any open or short circuit found in LED or there is any deviation observed in the current drawn by the LED blinker circuit from the current ratings set for the blinkers, then the microcontroller (303) sends a signal to turn off the LED blinker string. However, if no LED is open or short circuited, then the LED blinker string work as per the specification provided to the blinker system.
[00050] In an embodiment of the present invention, the microcontroller may be replaced
with a microprocessor, Application specific integrated circuit, Programmable gate array logic, field programmable gate array etc.
[00051] It would be appreciated that any of the foregoing may be implemented in the form
of software, hardware and/or firmware. Further, these functionalities may be implemented using a Controller, an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software instructions and/or other suitable logic or components that provide the described functionality.

[00052] The language used in the specification has been principally selected for readability
and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the disclosure be limited not by this detailed description, but rather by the following claims. Accordingly, the disclosure of the embodiments is intended to be illustrative, but not limiting, of the scope, which is set forth in the following claims.
[00053] Although the present invention has been described in considerable detail regarding
figures and certain preferred embodiments thereof, other versions are possible. Therefore, the scope of the present invention should not be limited to the description of the preferred versions contained herein.

We Claim:
1. A sequential blinker system, the system comprising:
a plurality of strings of series connected LEDs;
at least one diode connected in shunt with said plurality of strings of series connected LEDs;
a constant current unit having at least two channels, wherein first channel is connected to anode terminal of said at least one diode and second channel is connected to anode terminal of said plurality of strings of series connected LEDs;
a first switching unit;
a plurality of second switching units; and
a controller connected to the first switching unit and the plurality of second switching units, wherein said controller is configured to:
activate the first switching unit, connected to cathode terminal of said at least one diode, to provide constant current flow in first string of said plurality of strings of series connected LED, and deactivate said first switching unit, once the constant current is provided in subsequent string of series connected LED; and
activate at least one of a plurality of second switching units, connected to cathode terminal of LED of said plurality of strings of series-connected LEDs, to illuminate string of series-connected LEDs.
2. The sequential blinker system as claimed in claim 1, wherein only one of said second switching units is activated for string of series connected LEDs, at any given instant of time.
3. The sequential blinker system as claimed in claim 1, further comprising:
a body control unit (BCU) configured to:

send a signal to said constant current unit and said controller; and monitor current drawn through the plurality of strings of series connected LEDs at a predefined period.
4. The sequential blinker system as claimed in claim 3, wherein said BCU configured to send a signal to said controller, if the current drawn from any of the strings of series connected LED is below than a predefined threshold.
5. The sequential blinker system as claimed in claim 4, wherein said controller, upon determination that the current drawn by the string of series connected LED is below the threshold, is configured to send a signal to increase the frequency of illumination of LED present in string of series connected LED.
6. The sequential blinker system as claimed in claim 1, wherein said strings of series connected LEDs are connected in parallel.
7. A method for sequential blinking, the method comprising:
activating a first switching unit connected to cathode terminal of at least one diode to provide constant current flow in first string of a plurality of strings of series connected LEDs;
deactivating said first switching unit connected to cathode terminal of said at least one diode once the constant current is provided in subsequent string of series connected LED; and
activating at least one of a plurality of second switching units, connected to cathode terminal of LED of said plurality of strings of series-connected LEDs, to illuminate string of series-connected LEDs.
8. The method as claimed in claim 7, wherein activating only one of said second switching units
for the string of series connected LEDs at any given instant of time.
9. The method as claimed in claim 7, further comprising:
monitoring current drawn through the plurality of strings of series connected LEDs at a predefined period.
10. The method as claimed in claim 9, wherein the method comprises:

sending a signal to a controller if the current drawn from any of the strings of series connected LED is below than a predefined threshold.
11. The method as claimed in claim 10, wherein the method comprises:
sending a signal to increase the frequency of illumination of LED present in string of series connected LED if the current drawn by the string of series connected LEDs falls below the threshold.