F O R M 2

THE PATENTS ACT  1970
(39 of 1970)
COMPLETE SPECIFICATION
(See section 10; rule 13)

1. TITLE OF THE INVENTION
SYSTEM FOR ENABLING FLASHING OF INDICATOR LAMPS

2. APPLICANTS
a. Name: Race Dynamics India Pvt. Ltd.
b. Nationality: India
c. Address: Chikyallappa Industrial Estate  Jakkasandra  Koramangala 1st Block  Bangalore – 560034

Complete specification:
The following specification particularly describes the invention and the manner in which it is to be performed.

BACKGROUND
Field
The disclosed subject matter relates to the field of automobiles  more particularly but not exclusively  to turn signal indicator systems provided in automobiles.
Discussion of related field
[0001] A turn signal indicator system enables flashing of indicator lamps  which may be provided at the front and rear of an automobile. The flashing indicator lamps indicate the direction towards which the automobile is intended to turn.
[0002] A driver of an automobile activates either left or right side indicator lamps by activating a switch. Activating the switch enables electricity to be supplied from a battery to the indicator lamps  thereby illuminating the respective indicator lamps.
[0003] While illumination of the respective indicator lamps is enabled by activating the switch  flashing of the respective indicator lamps is enabled by a thermal flasher. The thermal flasher is placed in between the battery and the indicator lamps. The thermal flasher has a piece of steel spring provided adjacent to an electric contact  which is surrounded by a coil of resistor wire. As is well known  heating and cooling of the steel spring results in bending and regaining of its initial shape  respectively  thereby switching on and off the indicator lamps. Another conventional technique uses a mechanical relay with an Inductor  resistance and capacitor circuit that controls the on and off cycles of the indicator lamps. Such flashers have the ability to change the flashing frequency if one of the indicator lamps malfunctions. Although  the aforementioned techniques enable flashing of indicator lamps  it has been observed that such systems are prone to higher rate of failure.
[0004] In yet another conventional technique  electronic flasher is placed in between the battery and the indicator lamps. In this technique  irrespective of whether an indicator lamp is working or not  the remaining lamps flash at the same frequency. However  in case of failure of one of the lamps  the lamps should ideally flash at increased frequency  thereby alerting the driver that one of the lamps has failed.
[0005] In light of the foregoing discussion  there is a need for a more efficient turn signal indicator system.

STATEMENT OF INVENTION
[0006] Accordingly the invention provides a system for enabling flashing of indicator lamps. The system includes an input pin  an output pin  a vibrator circuit configured to receive voltage from the input pin and generate a wave form; a power drive circuit configured to receive input corresponding to the wave form from the vibrator circuit and regulate voltage at an output pin of the system  wherein the output is operably connected to one or more indicator lamps thereby grounding the system; and a feedback circuit configured to measure the current drawn by the connected one or more indicator lamps and regulate at least one of duty cycle and frequency of the vibrator circuit based on the measured current.
BRIEF DESCRIPTION OF DRAWINGS
[0007] Embodiments are illustrated by way of example and not limitation in the Figures of the accompanying drawings  in which like references indicate similar elements and in which:
[0008] FIG. 1 illustrates an example turn indicator system 10 provided in a vehicle  in accordance with an embodiment;
[0009] FIG. 1a illustrates a block diagram of a system 100 for enabling flashing of indicator lamps  in accordance with an embodiment;
[0010] FIG. 2 is an example system 100 layout illustrating circuit blocks and their interconnections  in accordance with an embodiment;
[0011] FIG. 3 is an example circuit layout of a module 102  in accordance with an embodiment;
[0012] FIG. 4a is an example circuit layout of a vibrator circuit 104  in accordance with an embodiment;
[0013] FIG. 4b  FIG. 4c and FIG. 4d illustrates example alternative circuit layouts of the vibrator circuit 104  in accordance with an embodiment;
[0014] FIG. 5 illustrates an example layout of a power circuit in a power drive circuit 106   in accordance with an embodiment;
[0015] FIG. 6a  FIG. 6b  FIG. 6c and FIG. 6d illustrates example alternative circuit layouts for a drive circuit in the power drive circuit 106  in accordance with an embodiment;
[0016] FIG. 7 illustrates an example feedback circuit 110 layout  in accordance with an embodiment;
[0017] FIG. 8 is another example system 100 layout illustrating circuit blocks and their interconnections without the module 102  in accordance with an embodiment; and
[0018] FIG. 9 illustrates an example alternative circuit layouts of the vibrator circuit 104  which can replace the module 102 in the system 100  in accordance with an embodiment.

DETAILED DESCRIPTION
[0019] The following detailed description includes references to the accompanying drawings  which form a part of the detailed description. The drawings show illustrations in accordance with example embodiments. These example embodiments  which are herein also referred to as “examples” are described in enough detail to enable those skilled in the art to practice the present subject matter. The embodiments can be combined  other embodiments can be utilized  or structural  logical  elemental and electrical changes can be made without departing from the scope of what is claimed. The following detailed description is  therefore  not to be taken in a limiting sense  and the scope is defined by the appended claims and their equivalents.
[0020] In this document  the terms “a” or “an” are used  as is common in patent documents  to include one or more than one. In this document  the term “or” is used to refer to a nonexclusive “or ” such that “A or B” includes “A but not B ” “B but not A ” and “A and B ” unless otherwise indicated.
[0021] Embodiments disclose a technique to enable flashing of indicator lamps provided in automobiles.
[0022] FIG. 1 illustrates an example turn indicator system 10 provided in a vehicle  in accordance with an embodiment. The turn indicator system 10 includes a voltage source 12  a system 100 for enabling flashing of indicator lamps  wherein a input pin of the system 100 is connected to the voltage source and a output pin of the system 100 is connected to a switch 14  right indicator lamps 16 and left indicator lamps 18. Initially  when the switch 14 is in neutral position  as indicated in the instant figure  voltage from the voltage source 12 is not supplied to either of the indicator lamps 16 and 18 as the ouput pin is not connected to any of the lamps. On the other hand  when the switch 14 is moved  either to the left or right  the output pin of the system 100 is connected to one or more lamps and the system 10 is grounded  thereby enabling supply of voltage from the voltage source 12 to either the left indicator lamps 18 or the right indicator lamps 16  based on the direction towards which the switch 14 is moved. The voltage is supplied from the voltage source 12 through the system 100  which enables flashing of the indicator lamps 16 or 18  which may be referred to as load.
[0023] FIG. 1a illustrates a block diagram of the system 100 for enabling flashing of indicator lamps  in accordance with an embodiment. The system 100 includes an input pin  an output pin  a conditioning and storage circuit 102  a vibrator circuit 104  a power drive circuit 106  a current sensing circuit 108 and a feedback circuit 110.
[0024] In an embodiment  the conditioning and storage circuit 102 (hereafter referred to as “module 102”) is connected to the voltage source 12  such as a battery through the input pin. Voltage supplied by the voltage source 12 is conditioned by the module 102. Further  module 102 is configured to store voltage. Furthermore  the module 102 prevents reverse flow of current through the input pin into the voltage source 12. Additionally  the voltage stored in the module 102 is supplied to the load through the output  when the system 100 is grounded by connecting the output pin to one or more lamps.
[0025] The vibrator circuit 104 is configured to control the operation of the power drive circuit 106 in accordance with the change in frequency or duty cycle of the vibrator circuit 104 output wave form. The power drive circuit 106 is configured to receive signal corresponding to the wave form from the vibrator circuit 104 and operate turn signal indicator lamps accordingly  based on the duty cycle and frequency of the received signal from the vibrator circuit 104. The current sensing module 108 is configured to sense the current drawn by the turn signal indicator lamps and feed it to the feedback circuit 110. The feedback circuit 110 is configured to receive the input from the current sensing circuit 108 and modifying the frequency or duty cycle of the vibrator circuit 104  thereby  modifying the operation of the power drive circuit 106.
[0026] FIG. 2 is an example system 100 layout illustrating circuit blocks and their interconnections  in accordance with an embodiment. The voltage through the input pin is applied to a diode of the module 102. The diode prevents reverse flow of current into the voltage source 12 and drives required voltage to other parts of the system 100. Capacitor of the module 102 is charged to peak voltage by the voltage passing through the diode. Further  the capacitor supplies additional power to the load through the output pin  when the system 100 is grounded.
[0027] FIG. 3 is an example circuit layout of the module 102  in accordance with an embodiment.
[0028] In an embodiment  the vibrator circuit 104 is a multi-vibrator circuit with a controlled on and off period of the output wave. The vibrator circuit 104 includes at least one transistor  one or more capacitors  one or more resistors. The vibrator circuit 104 can also include one or more passive elements.
[0029] In an embodiment  the vibrator circuit 104 can be any oscillator circuit wherein the frequency or duty cycle of output wave is governed by the combination of one or more passive elements.
[0030] FIG. 4a is an example circuit layout of the vibrator circuit 104  in accordance with an embodiment. The vibrator circuit 104 is configured as an astable multi-vibrator using two pnp transistors with associated capacitors and resistors required for necessary timing and transistor biasing as shown in the FIG. 4a and FIG. 2. The circuit is configured to control the output of the power drive circuit 106. This configuration can also be implemented using two npn transistors.
[0031] FIG. 4b  FIG. 4c and FIG. 4d illustrates example alternative circuit layouts of the vibrator circuit 104  in accordance with an embodiment.
[0032] In an embodiment  the functionality of the vibrator circuit 104 can be achieved by using or replacing one or more components with any know semiconductor device including but not limited to 555 timers IC  ASIC’s  FET and MOSFET  among others.
[0033] In an embodiment  the power drive circuit 106 can be further divided into two parts  namely  drive circuit and power circuit. The drive circuit is modified according to the type of power circuit incorporated into the system 100. For example  the power drive circuit 106 of FIG. 2 can be divided into two parts. The resistor of the power drive circuit 106 in FIG. 2 is the drive circuit and the transistor is the power circuit.
[0034] FIG. 5 illustrates an example layout of a power circuit in the power drive circuit 106  in accordance with an embodiment. The power circuit can be built as per the circuit shown in the FIG. 5 by replacing the section ‘Q’ with one or more FET’s  MOSFET’s and Darlington transistors  among others with necessary modifications to the circuit. Further  the appropriate drive circuit has to be incorporated for efficient operation of the power circuit.
[0035] In an embodiment the drive circuit is configured to control the power circuit drive characteristics and ensures the operation of the power circuit within safe and efficient limits. FIG. 6a  FIG. 6b  FIG. 6c and FIG. 6d illustrates example alternative circuit layouts for the drive circuit in the power drive circuit 106  in accordance with an embodiment.
[0036] FIG. 7 illustrates an example feedback circuit 110 layout  in accordance with an embodiment. The circuit is designed to monitor the current drawn by the load  and modify duty cycle or frequency of the vibrator circuit 104 output. This can be achieved by modifying the value of one or more passive elements in the vibrator circuit 104.
[0037] In an embodiment  the current sensing circuit 108 can measure the current drawn by the load as a voltage drop across a low resistance at the high side between input pin and the power circuit.
[0038] In an embodiment  the current sensing circuit 108 can measure the current drawn by the load as a voltage drop across a low resistance at the low side between the power circuit and the output pin of the system 100.
[0039] In an embodiment  the current drawn by the load can be measured by the feedback circuit 110 as a voltage drop between the high and low side of the power circuit by eliminating the need for an additional current sensing circuit 108.
[0040] FIG. 8 is another example system 100 layout illustrating circuit blocks and their interconnections without the module 102  in accordance with an embodiment. In the instant layout  module 102 is not provided and the vibrator circuit 104 and the feedback circuit 110 are altered.
[0041] FIG. 9 illustrates an example alternative circuit layouts of the vibrator circuit 104  which can replace the module 102 in the system 100  in accordance with an embodiment. The instant layout  can be used with the system 100 to eliminate the need of module 102.
[0042] In an exemplary embodiment  the turn indicator system 10 includes the voltage source 12 connected to the input pin of the system 100  left and right turn signal indicator lamps 18 and 16  and the switch 14 associated with left and right turn signal indicator lamps 18 and 16  and the system 100 output pin. Initially  when the switch 14 is in neutral position  the circuit is open. Further  when the switch 14 is operated towards left or right indicator lamps 18 and 16  the system 100 output pin is connected to the corresponding indicator lamps 18 and 16 and ground connection is established. The capacitor of the module 102 will be charging at this state.
[0043] Further  the vibrator circuit 104 starts working  with the frequency and duty cycle governed by resistor and capacitor combination. The power circuit is activated through drive circuitry. The activated power circuit directs the supply voltage from the input pin to left or right turn signal indicator lamps 18 or 16  gradually increasing the voltage at the output pin of the system 100  till it reaches a value approximately equal to the supply voltage 12.
[0044] Module 102 supplies the required voltage to the other parts of the system 100. As the ground voltage increase at the system 100 output  the voltage at module 102 increases proportionally due to the capacitor and diode. The duration of the stepped up voltage or discharge is dependent on the current drawn to the output pin of system 100 and capacitor value of module 102. The circuit is designed to hold this state higher than maximum ‘ON’ state of the vibrator circuit 104 duty cycle.
Further  the vibrator circuit 104 turns off the power drive circuit 106 and the voltage at the output of system 100 falls to ground levels. The capacitor in module 102 starts charging again. This process repeats as long as the output pin of the system 100 is connected to the left or right turn signal indicator lamps 18 or 16. Throughout this process  the current sensing circuit 108 measures the current drawn from the load  as a voltage drop across a low resistance at the low side between the power circuit and the output pin as shown in FIG. 2. The transistor circuit of the feedback circuit 110 identifies the faulty or non functional indicator lamp and varies the base and collector current of the transistors in vibrator circuit 104  thereby altering the flashing frequency or the duty cycle.
[0045] In an embodiment  the switch 14 is a mechanical switch.
[0046] In an embodiment  the switch 14 is an electronic switch.
[0047] In an embodiment  the left indicator lamps 18 includes two left turn indicator lamps L1 and L2  and an indication lamp associated with the turn indication system L3 as show in the FIG. 1. Further  the indication lamps L1 and L2 are higher wattage lamps than L3.
[0048] In an embodiment  the right indicator lamps 16 includes two right turn indicator lamps R1 and R2  and an indication lamp associated with the turn indication system R3 as show in the FIG.1. Further  the indication lamps R1 and R2 are higher wattage lamps than R3.
[0049] In an embodiment  an indicator lamps system can include two right turn indicator lamps R1 and R2  two left indicator lamps L1 and L2  and a common indication lamp replacing L3 and R3.
[0050] Although embodiments have been described with reference to specific example embodiments  it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the system and method described herein. Accordingly  the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
[0051] Many alterations and modifications of the present invention will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. It is to be understood that the description above contains many specifications  these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the personally preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents rather than by the examples given.

CLAIMS
We claim:
1. A system for enabling flashing of indicator lamps  the system comprising:
an input pin  wherein the input pin is connected to a voltage source;
a vibrator circuit configured to receive voltage from the input pin and generate a wave form;
a power drive circuit configured to receive input corresponding to the wave form from the vibrator circuit and regulate voltage at an output pin of the system  wherein the output pin is operably connected to one or more indicator lamps  thereby grounding the system; and
a feedback circuit configured to measure the current drawn by the connected one or more indicator lamps and regulate at least one of duty cycle and frequency of the vibrator circuit based on the measured current.
2. The system according to claim 1  wherein the power drive circuit comprises a drive circuit and a power circuit.
3. The system according to claim 2  wherein the drive circuit is configured to receive the input from the vibrator circuit and control the drive characteristics of the power circuit  and the power circuit is configured to regulate voltage at the output pin of the system based on input from the drive circuit.
4. The system according to claim 1  further comprising a conditioning and storage circuit configured to:
receive voltage from the input pin;
prevent reverse flow of current to a voltage source through the input pin;
store voltage; and
supply stored voltage to the output pin of the system  when the system is grounded.
5. The system according to claim 4  wherein the conditioning and storage circuit is further configured to condition the voltage received from the voltage source.
6. The system according to claim 4  wherein the conditioning and storage circuit comprises at least one of diode and resistor to prevent reverse flow of current to the voltage source through the input pin  and at least one capacitor to store and supply stored voltage to the output pin of the system.
7. The system according to claim 1  further comprising a current sensing circuit configured to measure the current drawn by the connected one or more indicator lamps and feed it to the feedback circuit.
8. The system according to claim 7  wherein the current sensing circuit is configured to measure the current drawn by the connected one or more indicator lamps as a voltage drop across a low resistance at a high side between the input pin and the power circuit.
9. The system according to claim 7  wherein the current sensing circuit is configured to measure the current drawn by the connected one or more indicator lamps as a voltage drop across a low resistance at a low side between the power circuit and the output pin of the system.
10. The system according to claim 7  wherein the current sensing circuit is configured to measure the current drawn by the connected one or more indicator lamps as a voltage drop across a drive circuit.
11. A system for enabling flashing of indicator lamps as herein above described in the specification with reference to figures.

ABSTRACT
A system (100) for enabling flashing of indicator lamps includes a vibrator circuit (104)  an input pin  an output pin  a power drive circuit (106) and a feedback circuit (110). The vibrator circuit (104) is configured to receive voltage from the input pin and generate a wave form. The power drive circuit (106) is configured to receive input corresponding to the wave form from the vibrator circuit (104) and regulate voltage at the output pin of the system (100)  wherein the output pin is operably connected to one or more indicator lamps thereby grounding the system. The feedback circuit (110) is configured to measure the current drawn by the connected one or more indicator lamps and regulate at least one of duty cycle and frequency of the vibrator circuit (104) based on the measured current.
Reference figure: FIG. 2