FIELD OF INVENTION:
[001] The present subject matter described herein, relates to a electrical 5 architecture for distribution of electric power in emergency vehicles, and, in particular, to a electrical architecture for distributing electrical power to control and protect warning system for lighting and audio used in emergency vehicles. More particularly, the present subject matter relates to electrical system with a plurality of fuse and a relay to control and protect warning system of the 10 emergency vehicles.
BACKGROUND AND PRIOR ART:
[002] Generally, emergency vehicles have revolving lamp and siren for emergency information to public. The emergency vehicles can be ambulance, fire extinguisher vehicle, police vehicle and any other which is used by government or 15 organisation during emergency time period. Conventionally, the revolving lamp and sire in the emergency vehicles can be operated separately. For example, revolving lamp and siren or speaker receives electrical power separately from the vehicle’s battery. Accordingly, the revolving lamps and siren are operated independently through switches in the vehicle. 20
[003] Now there is a government regulation AIS 125 which mandates that siren switch or public addressing switch or speaker can only be used if the revolving lamp is ON along with the presence of a Public address system and a 12V accessory socket.
[004] Fig. 1 illustrates architecture or system of electrical power distribution in 25 emergency vehicles as known in the art. The electric power distribution system 100 has a battery 101, an ignition switch 103, a revolving lamp switch 106, revolving lamp 108, speaker switch 105, and speaker 107. The revolving lamp switch 106, revolving lamp 108, speaker switch 105, and speaker 107 collectively
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make a warning system. The warning system receives power from the ignition switch 103 when the ignition switch 103 is in accessory mode and in start mode. The warning system is connected with the ignition switch 103 via a fuse 104 can be referred as ambulance (AMB) fuse 104. Further, the ignition switch 103 is connected with the vehicle’s battery 101 via fuse 102 which can be referred as 5 ignition (IGN) fuse 102. The power flows from battery 101 to the ignition switch 103 via IGN Fuse (60A) 102 to the warning system. As loads have to be operated in ACC Mode, therefore the power flows to loads, i.e., speaker 107 and revolving lamp 108 via AMB fuse connected to the ignition switch 103. The revolving lamp 108 and the speaker 107 siren are operated independently through switches. 10 Therefore, the existing system does not fulfil the requirements of the regulation AIS 125.
[005] Conventionally, some solutions exist to solve this problem, but each solution has its limitations and problems.
[006] US patent publication US 8786423 B2 titled “Programmable control for 15 siren and lights” discloses a system comprising a power supply, an emergency warning light and a speaker, in combination with a control head. One or more processors controls operation of the system in response to received user input and provides system status for display. Storage media encoded with emergency warning light system instructions for execution by one or more of the processors 20 controls the actuation of the emergency warning light system and controls light patterns generated by the emergency warning light system. The storage media is further encoded with siren system instructions for execution by one or more of the processors for controlling the actuation of the siren system and for controlling audible sounds generated by the siren system. In this solution, embedded 25 processor system is used for controlling the system which increases the cost and complexity of the system.
[007] US patent publication US8193928B1 titled “Visible and audible warning signal operating and control apparatus integrated into a single unit” discloses an apparatus for controlling visible and audible warning signals, particularly signals 30
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from light bars, traffic director lighting, and siren and public address outputs for police and emergency vehicle applications, is provided in a single unit. Mounted in a chassis of the unit in layered relationship are a siren board and a relay board. The siren board contains amplifier and associated circuitry for generating and amplifying siren signals, and for providing microphone signals and signals from a 5 2-way radio of the vehicle, to a speaker which projects these audible signals for warning of and controlling emergency conditions. The relay board contains circuitry for switching power from the vehicle battery to the traffic director lighting and warning lighting (as may be provided by light bars) mounted on or in the vehicle. A microcontroller switches the lighting to the selected lighting units 10 via relays on the board. A controller utilizing buttons providing a keypad, rotary and slide switches, is mounted on the chassis at one end thereof to provide manual access to the police or other emergency personnel for controlling the lighting and the siren, as well as public announce and radio audible signals. This solution uses a embedded microcontroller for controlling the system which increases the cost 15 and complexity of the system.
[008] Further, existing technical solutions for the present technical problem has use of Fault Management system, i.e., a dedicated controller for monitoring and managing loads. Another solution uses customized PCB with semiconductor components for managing logic and power flow in the vehicle. Both the above 20 mentioned method increases the cost and complexity of the system significantly.
[009] Hence there is need for technical solution which can solve the problem without adding significant cost and complexity. The technical solution for the warning system should be inexpensive, reliable, simple in manufacturing, and easy to implement. Accordingly, the present invention provides a electric power 25 distribution system by satisfying all the requirements for regulation AIS 125 and allowing interdependent working of revolving lamp and speaker. s
OBJECTS OF THE INVENTION:
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[0010] The principal objective of the present invention is to provide an electrical system for distribution of electrical power to control and protect warning system for lighting and audio.
[0011] Another object of the present subject matter is to insulate accessory socket from the warning system having revolving lamp and speaker. 5
[0012] Another object of the present subject matter is to provide an electrical system which uses four fuses and a relay to provide power distribution to control and protect warning system from any fault in accessory socket.
[0013] Another object of the present subject matter is to provide an electrical system which distributes power to accessory socket and warning system. 10
[0014] Another object of the present subject matter is to allow operation of speaker when revolving lamp is ON.
[0015] Yet another object of the present subject matter is to provide a simple, effective, and cost efficient electrical system for distribution of electrical power to accessory socket and warning system of emergency vehicles. 15
SUMMARY OF THE INVENTION:
[0016] The subject matter herein relates to an electrical system for distribution of electrical power to warning system and accessory socket of an emergency vehicle. The electrical system includes a battery which is vehicle’s battery, an ignition switch, an accessory socket, and a warning system having a revolving lamp and a 20 public addressing speaker. The electrical system includes a plurality of fuses, specifically, four fuses and a relay to distribute electric power among the accessory socket and the warning system. The electrical system distributes the electric power in a manner that when any fault occurs either in accessory socket or in warning system, the fault does not hamper working of other system or 25 component. The ignition switch is connected with the battery of the vehicle via an ignition fuse. If there is any fault in the ignition switch, the ignition fuse will blow and protect the system. The accessory socket is connected with battery and the ignition switch via a relay. When the ignition switch is in accessory mode, the
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ignition switch energizes the relay which activates the accessory socket. Further, if there is any fault in the accessory socket, the accessory switch at the ignition switch side blown off to protect further damage in the accessory socket. The warning system is connected with the ignition switch via an ambulance fuse which is normal fuse. According to structure or architecture of the present 5 electrical system, the accessory socket is connected with the ignition switch via different set of fuses and the warning system is connected with different fuse. Therefore, if there is any fault either in accessory socket or in warning system, the fault does not hamper working of other system or component.
[0017] In order to further understand the characteristics and technical contents of 10 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
[0018] It is to be noted, however, that the appended drawings illustrate only 15 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 20 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:
[0019] Fig. 1 illustrates architecture of electrical system for distribution of electric 25 power to warning system of emergency vehicle as known in the art; and
[0020] Fig. 2 illustrates electrical system for distribution of electric power separately to accessory socket and revolving lamp and speaker of emergency vehicle, in accordance with an embodiment of the present subject matter.
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[0021] 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. 5
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0022] The subject matter herein relates to an electrical system for distribution of electrical power to warning system and accessory socket of an emergency vehicle. The electrical system includes a battery which is vehicle’s battery, an ignition switch, an accessory socket, and a warning system having a revolving lamp and a 10 public addressing speaker. The electrical system includes a plurality of fuses, specifically, four fuses and a relay to distribute electric power among the accessory socket and the warning system. The electrical system distributes the electric power in a manner that when any fault occurs either in accessory socket or in warning system, the fault does not hamper working of other system or 15 component. The ignition switch is connected with the battery of the vehicle via an ignition fuse. If there is any fault in the ignition switch, the ignition fuse will blow and protect the system. The accessory socket is connected with battery and the ignition switch via a relay. When the ignition switch is in accessory mode, the ignition switch energizes the relay which activates the accessory socket. Further, 20 if there is any fault in the accessory socket, the accessory fuse at the ignition switch side blown off to protect further damage in the accessory socket. The warning system is connected with the ignition switch via an ambulance fuse which is normal fuse. According to structure or architecture of the present electrical system, the accessory socket is connected with the ignition switch via 25 different set of fuses and the warning system is connected with different fuse. Therefore, if there is any fault either in accessory socket or in warning system, the fault does not hamper working of other system or component.
[0023] The warning system includes a revolving lamp switch which is connected with revolving lamp and public addressing speaker. When revolving lamp switch 30
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is pressed, it activates the revolving lamp. Further, the public addressing speaker has a switch for its operations. Due to present construction of the electrical system, the public addressing speaker activates only when the revolving lamp switch is pressed. The warning system receives power from the battery when the ignition switch is in accessory mode. Accordingly, the present electrical system 5 satisfy and solve the technical problem of the existing solutions in a much cheaper way by adding two extra fuses and a relay in the structure. Further, the present system also meets requirements of the regulations AIS 125.
[0024] 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 10 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 assembly that, although not explicitly described or shown herein, embody the principles of the present subject matter 15 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 20 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. 25
[0025] 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
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various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0026] Fig. 2 illustrates electrical system for distribution of electric power separately to accessory socket and revolving lamp and speaker of emergency vehicle, in accordance with an embodiment of the present subject matter. The 5 emergency vehicles can be ambulance, fire extinguisher, and any police van or vehicle which can be used during emergency time period. Further, the present subject matter is explained by considering ambulance as an emergency vehicle. Further, the present subject matter of the invention can be implemented in any vehicle, specifically, in any emergency vehicle without any limitation of vehicle 10 type, such as hatchback, sedan, SUV, MUV, VAN. Further, the present subject matter illustrates a revolving lamp which can be of any existing lighting device which can be used in the emergency vehicles. Furthermore, the present subject matter illustrates a public addressing speaker which can be a siren or combination of speaker and mike, or a speaker only or any other audio device which can be 15 used to address or to alert the public at large.
[0027] The ignition switch of a vehicle has several modes of working. In the lock position, no accessories work take place. In this position key of the vehicle can be taken out from the ignition. In accessory mode, accessory, such as radio, as well as use some other electronics can be used. In this mode, the key cannot be 20 removed from the ignition. In the On mode, all electronics of the vehicle can be operated. Further, the key cannot be removed from the ignition. The key will also default to this position after crank the engine.
[0028] The electrical system 200 is basically a electrical distribution system which control power flow in the existing structure or architecture by using 25 additional relay and fuses. The electrical system 200 includes a battery 201, an ignition (IGN) fuse 202, an ignition switch 203, two accessory (ACC) fuses 204, 205, a ambulance (AMB) fuse 206, a relay 207, an accessory socket 209, and a warning system 213. The ignition (IGN) fuse 202, the two accessory (ACC) fuses 204, 205, and the ambulance (AMB) fuse 206 are normal fuses. Here 30
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nomenclature is given for clear identification of switches and its component for which it is provided. The warning system 213 includes a revolving lamp switch 208, a revolving lamp 212, a public addressing system 210 having public addressing speaker 211. Further, electric wires are used to connect each component of the electrical system with the ignition switch and battery. 5
[0029] The ignition switch 203 is connected with the battery via IGN fuse 202. The IGN fuse 203 protects the ignition switch 203 and the battery for any fault. The accessory socket 209 is connected with the battery 201 and the ignition switch via the relay 207. Further, the relay 207 is connected with the ignition switch 203 and the battery via two accessory ACC fuses 204, 205 which protects 10 the accessory socket 209 and the ignition switch 203 from each other in situation of a fault. The fuse (ACC Signal) 205 protects the coil of relay 207 being driven through the ignition switch 203. The relay 207 provides power to the accessory socket 209 via the ACC fuse 204. The accessory socket 209 operates whenever the ignition switch is ON in the ACC mode. 15
[0030] Other embodiment, i.e., warning system 213 of the present subject matter is connected with the ignition switch 203 via an AMB fuse 206 which protects the electrical system from damage when there is any fault in the warning system 213. The revolving lamp switch 208 of the warning system 213 is connected with the ignition switch 203 via the AMB fuse 203. Further, the revolving lamp switch 208 20 is connected with the revolving lamp 212 and the public addressing speaker 210. Both the revolving lamp 212 and the public addressing speaker 210 are operated by the revolving lamp switch 208. If the revolving lamp switch 208 is ON, the revolving lamp 212 and the public addressing speaker 210 works. Further, the public addressing speaker 210 has a switch which is used to operate or ON or 25 OFF the public addressing speaker 210. From the present structure, the public addressing speaker 210 is activated only after activation of the revolving lamp 212 by the revolving lamp switch 208. Upon pressing the revolving lamp switch 208, power flows into the revolving lamp 212 and the public addressing speaker 210.
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[0031] All loads operated in ACC mode of the ignition switch has maximum of 10A load. Each fuse has different threshold capacity, for example, IGN fuse has 60 A, ACC fuse 204 has 15 A, ACC fuse 205 has 7.5 A, the AMB fuse has 15A, and the relays 207 has 20 A load capacity. As each component can have 10 A load, the accessory socket 209 can have 10 A load and warning system 213 can 5 have 10 A load. In an event of short circuit at any of the loads, i.e., accessory socket and warning system, the corresponding fuse blows, thus preventing other loads being rendered useless. This would prevent compromise with other systems during fault conditions.
[0032] The present electrical system 200 insulates the warning system 213 from 10 the accessory socket 209 with the help of four fuses and a relay. According to structure of the present electrical system, the accessory socket is connected with the ignition switch via different set of fuses and the warning system is connected with different fuse. Therefore, if there is any fault either in accessory socket or in warning system, the fault does not hamper working of other system or component. 15
[0033] The present subject matter provides a low cost mechanism and solution to effectively control of warning systems while providing over current protection against short circuits. The advantage of such a system is that it can be incorporated into existing system without any new development/modification. Due to use of different fuses, it becomes easy for the user to identify the faulty 20 fuse and the user can easily replace it. So serviceability during replacement of fuse becomes easy. Therefore, independent working of loads and ease of fuse serviceability added value to the present electrical system.
[0034] Other technical and economic advantages associated with the present subject matter is: 25
[0035] Independent over current protection for each load. (Incase fuse for accessory load blows due to short Circuit, ambulance system would still operate and vice a versa).
[0036] Cost effective system with addition of only 2 fuses and a relay.
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[0037] No new parts development/modification required to comply regulatory changes.
[0038] Ease of fuse replacement by user in an event of fault.
[0039] Optimized power flow based on existing component maximum current ratings.(Relay 20A,Switch 7A, Ignition Switch ACC mode 10A) 5
[0040] The term “vehicle” as used throughout this detailed description and in the claims refers to any moving vehicle that is capable of carrying one or more human occupants and is powered by any form of energy. The term “vehicle” is a motor vehicle which includes, but is not limited to: cars, trucks, vans, minivans, hatchback, sedan, MUVs, and SUVs. 10
[0041] 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 15 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 20 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 25 feature.
[0042] 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,
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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. 5

We claim:
1. A electrical system (200) for distribution of electrical power to warning system (212) of an emergency vehicle, the electrical system (200) comprising:
an ignition switch (203) connected with the battery (201) via ignition 5 (IGN) fuse (202);
an accessory socket (209) connected with the battery (201) and the ignition switch (203) via relay (207);
a warning system (213) connected with the ignition switch (203) via ambulance (AMB) fuse (206), wherein the ignition switch (203) supplies 10 electrical power from the battery (201) when accessory mode is ON.
2. The electrical system (200) as claimed in claim 1, wherein the warning system (213) comprises :
a revolving lamp switch (208) connected with revolving lap (212); 15
a public addressing speaker (211) connected with the revolving lamp switch (208), wherein the public addressing speaker (211) receives power from the revolving lamp switch (208).
3. The electrical system (200) as claimed in claim 2, wherein the public 20 addressing speaker (211) is operated by a switch.
4. The electrical system (200) as claimed in claim 1, wherein the relay (207) of the accessory socket (209) connected with the ignition switch (203) via an accessory (ACC) fuse (205) and with battery (201) via an accessory (ACC) 25 fuse (203).
5. The electrical system (200) as claimed in claim 1, wherein the warning system (213) insulated from the accessory socket (209).
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6. The electrical system (200) as claimed in claim 1, wherein the accessory (ACC) fuse (205) fused when any fault in the accessory load in the accessory socket (209).
7. The electrical system (200) as claimed in claim 1, wherein the ignition 5 switch (203) has three mode accessory mode (ACC), ignition mode (IGN), and off mode.
8. The electrical system (200) as claimed in claim 1, wherein the AMB fuse (206) protects the warning system (213) from fault. 10
9. The electrical system (200) as claimed in claim 1, wherein the accessory socket (209) and the warning system (213) operates on 10A current.