COMPLETE AFTER PROVISIONAL
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22 FEB 2007
FORM 2

THE PATENTS ACT, 1970 (39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
THE PATENTS RULES, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION (See section 10 and rule 13)
TITLE OF THE INVENTION
A system for protecting voltage sensitive vehicle components
INVENTORS
Names : 1. Karnik Rohit Bipin
2. Bopardikar Mangesh Madhusudan
3. Renavikar Pramod Bhagwant Nationality: all Indian Nationals
Address : Bajaj Auto Limited, Akurdi, Pune 411035, Maharashtra, India
APPLICANTS
Name : Bajaj Auto Limited
Nationality : Indian Company
Address : Akurdi, Pune 411035, Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following description particularly describes the invention and the manner in which it is to be performed.

This invention relates to system for protecting voltage sensitive vehicle components, such as vehicle lighting systems, from voltage peaks and surges.
Background of the Invention:
Automotive vehicles are provided with headlights for illuminating the road ahead and front and rear position lights to indicate presence of vehicle and instrument console lights to illuminate various instruments. These lights operate either on a dc supply eg by battery, or particularly in case of small vehicles, on ac supply eg as generated by magneto and regulated by the regulator. In order to turn these lights ON and OFF, manual control switches are provided at locations convenient to the driver.
During driving of vehicle in evening or conditions of poor visibility, the driver may not be vigilant to switch ON these lights. If the lights are not switched ON, this becomes a safety hazard for other road users. An automatic switching circuit for vehicle lights like head lights, front and rear position lights and instrument console lights primarily comprises a sensor, which senses the ambient light and enables the controller to switch ON the lights automatically, if the sensed ambient light is less than a predetermined value. Automatic control may be in addition to manual control.
In order to facilitate automatic switching OFF and switching ON of such lights, in case the driver forgets to operate manual switches, various systems have been provided.
1. Patent JP2003118475A2 discloses a system wherein a sensor determines ambient light levels and visibility for switching OFF and ON of vehicle lights.
2. US 3879617 discloses use of SCHMITT trigger in automatic control device wherein fluctuations in the environmental illumination does not cause repeated switching ON and OFF of vehicle lamps.
3. EP 0911216B1 discloses an automatic lighting system wherein two light sensors are used. One sensor analyses the natural light and the second sensor artificial light, and enabling switching ON and OFF trigger lights as dictated by the processing of signals from the first and second sensors.
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The systems mentioned above and the like involve, sensing of ambient light
condition and other conditions to enable switching ON and OFF of vehicle lights wherein
dc supplies are involved and/or are used on cars.
While such systems are conceptualized on smaller vehicles having lights operating on ac supplies generated by lighting coil of magneto and regulated by a regulator, one of the problems experienced is risk of fusing of the bulbs due to excessive voltage in the lighting system in the period till the voltage regulator starts controlling the voltage, particularly when the vehicle is started in night or similar conditions. When a vehicle with an ambient light sensor is located in a darker area in the daytime or at night times and the driver starts the vehicle either by a kick or a starter motor, the magneto initiates electricity supply. The sensor triggers the lights ON but the regulator takes some time to achieve proper voltage regulation. Within the duration from an instant of sensor triggering the lights ON and the regulator achieving proper voltage regulation, the lighting coil of magneto may generate voltage peaks or surges, not sustainable by the bulbs which may lead to fusing of bulbs. Other vehicle components may also be damaged by such voltage peaks or surges.
It is therefore the object of the present invention to provide systems for protecting voltage sensitive vehicle components to make these less susceptible to damage by voltage peaks or surges.
With this object in view, the present invention provides a system for protecting a voltage sensitive vehicle component operated on an alternating current supply generated by a magneto and having a voltage regulation means comprising a controller for delaying or preventing supply of electricity to said component. The said delay may be for a predetermined period. The predetermined period is a time sufficient for the voltage regulation means to achieve proper regulation so that the electricity supply voltage characteristic is at a permissible non-damaging value. This period may be pre-set at the factory based on a statistical analysis of typical voltage regulator performance.
Further, the controller may delay or prevent supply of electricity to the component until an electricity supply voltage characteristic is determined or sensed to be at a
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permissible value for supply of electricity to said voltage sensitive component. As the electricity supply voltage characteristic is, engine speed dependent, the controller may operate in dependence on engine speed. The component may be a light or lighting system of the vehicle or any voltage sensitive device. Delay may be implemented, for example by the controller, on start-up of the engine when voltage peaks or surges that may cause damage are prone to occur.
In a further aspect, the present invention provides a vehicle lighting system having at least one light operated on an alternating current supply generated by a magneto and comprising:
(a) sensing means for determining supply voltage characteristic of electricity
available to said at least one light; and
(b) control means for controlling supply of electricity to the light
wherein said control means actuates illumination of said at least one light, on command, when said supply voltage characteristic is determined to be at a permissible value for supply of electricity to said at least one light.
The control means or the controller will control supply of electricity to a light within the lighting system such that the light is protected from voltage peaks or surges which may be experienced on engine start up whether by kick start or electric start. The lighting system may involve an automatic switching mode, the controller enabling a process for switching lights ON or OFF dependent on sensed ambient light conditions, sensed light value falling below a pre-determined value causing a command that the control means actuate the light(s) of the lighting system. Alternatively, the lighting system may have a manual mode, where risk of light damage might still occur in the absence of control over the supply of electricity to the light(s). In this case, the user actuating the light switch forms the command to the control means to actuate the light(s).
In an automatic mode, suitable for a small vehicle with one or more lights working on an ac supply generated by a magneto] the automatic switching system may include an electronic timer, of electronic or similar kind and two sensing means or sensors. The first sensor determines supply voltage characteristics proportional to engine speed. This sensor may - for example - sense the voltage and/or frequency of voltage generated in a
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lighting coil of the magneto, this generated voltage or voltage frequency being proportional to engine speed. Accordingly, it may not be necessary to use a voltage sensor. Any sensor that may be used to determine, qualitatively or quantitatively, voltage characteristics generated in the lighting coil may be used. Such a sensor may, most likely, be a sensor of an electrical characteristic but this is not essential.
The second sensor is an ambient light sensor such as a light dependent resistor, the resistance of which changes with ambient light. Other sensors could be employed if desired. The sensor signals are received by a controller. The controller is capable of delaying the start of lights by duration, which is more than the duration required for a voltage regulator of the vehicle to control the supply voltage characteristic. The end of the delay period is set as at a set time from the instant when the ambient light sensor initiates switching ON of the lights. Alternatively, the end of the delay period may be set as the instant when voltage generated in lighting coil of magneto (which is proportional to
engine speed) or the voltage frequency reaches a predetermined value or falls within a
i range of values enabling safe or permissible operation of the lights, whichever is later.
During this time delay, the regulator starts voltage regulation and excessive voltage is not
passed to the bulbs, even if accelerator is raised, reducing risk of failure.
Further, the controller may operate the lighting in dependence on sensed ambient light levels. For example, when such an automatic switching system turns the lights ON, it is possible that the vehicle may pass through areas where ambient light is less or more than the predetermined value. The light sensor senses the condition and keeps the lights ON if the ambient light is less and switches it OFF after a predetermined delay if the ambient light level is more than the predetermined value, such delay forming a further aspect of the present invention. For example, if the sensed lighting level remains below a value, Y, for more than a predetermined delay (say 2 seconds), then the lights will switch
ON. If sensed lighting level remains above a value, X, for a predetermined delay, which
could, for example, be 15 seconds or 60 seconds), the lights will switch OFF. A timer
may reset the predetermined delay dependent in flucuations in sensed lighting levels. For
example, the counting time may be reset whenever the lighting level fluctuates from more
than X and less than Y.
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Description:
The system for protecting voltage Sensitive components of the invention may be more fully understood from the following description of preferred but non-limiting embodiments thereof made with reference to the accompanying drawings in which:

Figure 1 illustrates a two-wheeled various lights and a sensor for sensing the the system of the invention.

motor vehicle with a lighting system having ambient light according to one embodiment of

Figure 2 illustrates a circuit diagram of the two-wheeled vehicle of Figure 1.
Figure 3 is a diagram of logic employed in the lighting system of the two-wheeled vehicle of Figure 1 during starting of the vehicle.
In a two-wheeled vehicle 1, being a motor scooter, a lighting system includes a headlight 2 is provided for lighting the road ahead. The headlight 2 comprises a high beam, a low beam and if provided, a front position light 2a to recognize the presence of vehicle from the front, when the engine is running. The vehicle also comprises a rear position light 3, commonly known as taillight, to recognize presence of vehicle from rear. The instrument console 4 comprises indicating instruments such as speedometer, fuel gauge etc., which are illuminated by an ac supply to bulbs 4a, which facilitate reading of instruments in night times or such conditions. In order to sense the luminous intensity of ambient light and sending signals to the controller 7, a light sensor 5 is provided in the instrument console 4. Light sensor 5 is a light dependent resistor. The magneto 9 supplies electricity to the lights 2, 2a, 3 and 4a, which could be damaged by unregulated voltage surges or peaks, through voltagd regulator 10. The voltage sensing means 8 is conveniently located to sense the voltage (generated in lighting coil of the magneto (which is proportional to engine speed).
As illustrated in Figure 2, the control switch is a 3-position switch 6a, in which, first position (0 position) is for all lights in OFF condition. Second position (P position) is for the front position, rear position and instrument console lights in ON condition. Third

position (H position) is for headlight 2 in ON condition. A separate switch 11 for
selection of headlight main beam or passing beam is also provided. The light sensor 5 is
electrically connected to the controller 7 Another sensing means 8 is conveniently
located, which senses voltage or other voltage characteristic, such as voltage frequency, generated in lighting coil of magneto (which is proportional to engine RPM) and feeds the signals to the controller 7. The controller 7J sends output to the bulbs of the lights 2, 2a, 3,4a.
Figure 3 provides and explains a logic diagram or flowchart illustrating operation
of protection system for vehicle lights involving light sensor 5 and voltage sensing means
8 and having manual and automatic modes. When a kick-start or electric start starts the
engine, and the light switch is in OFF position, the sensing means 8 senses the voltage
generated in the lighting coil of magneto which is proportional to engine speed) and the
ambient light. If the engine speed is less than a predetermined value X, say 800 RPM,
there is no problem of bulb fusing since the voltage generated is less. When the engine
speed is more than this value and the ambient light is less than a predetermined value X
(say 6 lux), the controller 7 delays the lights ON condition for a predetermined period say
2 seconds, avoiding the possibility of fusing of light bulbs. During this period, the
regulator 10 starts regulation and normal working of the lights, within a permissible
voltage range, is initiated. The light sensor 5 continues to sense the ambient light and
sends signals to controller 7. If the ambient light is less than a predetermined value X, the
controller 7 keeps the lights 2 and 2a ON and switches them OFF if the ambient light
value is more than the predetermined value after a time lag of say 15 seconds. To avoid
possibility of fusing of bulbs, in case the driver uses a manual control switch during start
of the vehicle, a time delay of say 0.5 seconds to switch ON the lights is introduced in the
circuit. Manual switching otherwise overrides the auto mode.
Different ambient light levels ma| be set at which switching ON of position lights 2a (Front position lights, Rear position lights, Instrument console lights) and Head light occurs.
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For example, the position lights 2a, 3 and instrument console lights 4a may switch ON at a ambient level 'X' ( « 6 lux) after a delay of 2 to 3 seconds and switch OFF at a level > X after a delay of 15 seconds.
The head light 2, position lights 2a and, instrument console lights switch ON at a ambient level ' Y' (« 2 lux) after a delay of 0.5 seconds and switch OFF at a level > X after 60 seconds.
The predetermined ambient light level at which light sensor 5 indicates switching
ON or OFF of the vehicle lights is derived) from conditions such as the visibility criterion

of both vehicle driver and other road users,! regional conditions and so on.
The vehicle lighting system described above has the below operating characteristics:
a) If, when in Auto mode, the lights are ON, the light switch 6a is in OFF
position and the vehicle 1 is in running condition and the driver wants to switch OFF the

lights, the lights can be switched OFF by (a) moving the light switch 6a once from OFF to
ON position and again to OFF position or (b) switching the ignition switch of vehicle 1 from the ON position to the OFF position.
b) When light switch 6a is in ON position, the lights are ON (either position
lights 2 and Instrument console lights 4a and/or head light 2a depending on the
position/mode of lights switch), the ambient light is less than predetermined level (X) and
the vehicle 1 is in running condition the lights may be switched OFF by moving the light
switch from the ON position to the OFF position.

c) Any engine start up and engine speed greater than a. predetermined
threshold speed (say 800 RPM) will result in the lighting system being maintained in automatic mode (provided that the vehicle light switch is in OFF position). It will be understood that such operating characteristics may be modified within the scope of the invention.
Modifications and variations to the vehicle lighting system of the present
invention may be apparent to the skilled reader of this disclosure. Such modifications and
variations are considered to be within the scope of the present invention. For example,
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the description and the illustrations relate to a two-wheeled vehicle wherein light sensor 5 is located in instrument console 4. However, one or more ambient light sensors 5 can be conveniently located on other parts of the vehicle. Also, similar system can be adopted for three-wheeled motor vehicles and other, vehicles having lights working on ac supplies. The light sensor 5, in vehicles having a closed body or cabin can be appropriately relocated externally. The lighting system may also use a sensor other than a light dependent resistor, which is suitable to the (application. Also, if preferred, the system can
be used only for switching ON OFF of lights working on ac supplies only and other

vehicle lights can be on dc supplies.
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We claim :
1. A system for protecting a voltage sensitive vehicle component operated on an alternating current supply generated by a magneto and having a voltage regulation means comprising a controller for delaying or preventing supply of electricity to said component.
2. The system of claim 1 where the said delay is for a predetermined period.
3. The system of claim 2 wherein the predetermined period is a time sufficient for an electricity supply voltage characteristic for electricity to be supplied to the component to attain a permissible non-damaging value.
4. The system of claim 2 or 3 wherein the predetermined period is pre-set during manufacture of the controller.
5. The system of any one of the preceding claims wherein the controller delays or prevents supply of electricity to the component until an electricity supply voltage characteristic is determined or sensed to be at a permissible value for supply of electricity to said voltage sensitive component.
6. The system of any one of | the preceding claims wherein said delay is
I implemented on start-up of the! engine.
7. The system of any one of the preceding claims wherein the controller operates in dependence on engine speed.
8. The system of claim 1 wherein the voltage sensitive vehicle component is a vehicle light.
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9. The system of any one of the preceding claims having at least one light
operated on an alternating current supply generated by a magneto and
comprising:
(a) sensing means for determining supply voltage characteristic of electricity available to said at least one light; and
(b) control means for controlling supply of electricity to the light,
wherein said control means actuates illumination of said at least one light, on command, when said supply voltage characteristic is determined to be at a permissible value for supply of electricity to said at least one light.
10. The system of claim 9 comprising an automatic switching mode, the control means enabling a process for switching lights ON or OFF dependent on sensed ambient light conditions, sensed light value falling below a pre-determined value causing a command that the control means actuate the light(s) of the lighting system.
11. The system of claim 9 comprising a manual mode,
12. The system of claim 9 wherein the user actuating the light switch forms the command to the control means to actuate the light(s).
13. The system of claim 9 comprising:

(a) a timer;
(b) a first sensor fo(r determining supply voltage characteristics proportional to engine speed; and
(c) an ambient light sensor; and
(d) a controller to receive signals from the first sensor and ambient light sensor
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wherein the controller delays the start of lights by a duration greater than the duration required for a voltage regulator of the vehicle to control the supply voltage characteristic.
14. The system of claim 13 wherein the first sensor senses the voltage characteristic such as voltage and/or frequency of voltage generated in a lighting coil of the magneto.
15. The system of claim 13 wherein the end of the delay duration is set as at a set time from the instant when the ambient light sensor initiates switching ON of the lights.
16. The system of claim 13 wherein the end of the delay duration is set as the instant when voltage generated in a lighting coil of the magneto reaches a predetermined value.
17. The system of claim 13 wherein the end of the delay duration is set as an instant when frequency of voltage generated in a lighting coil of the magneto reaches a predetermined value.
18. The system of any one of claims 13 to 17 wherein the controller operates lighting in dependence on sensed ambient light levels.
19. The system of claim 18 wherein the controller switches lighting OFF after a
predetermined delay if the ambient light level is more than a predetermined
level.

20. The system of claim 18 or 19 wherein the timer resets the predetermined delay
dependent on fluctuations in lighting level.
21. A vehicle comprising the system of any one of the preceding claims.
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22. The system for protecting a voltage sensitive vehicle component substantially as hereinbefore described with reference to the drawings.
Dated this 21st day of February 2007
(Shilpa Gharve)
of Khaitan & Co
Agent for the Applicants
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