TECHNICAL FIELD
The present disclosure relates to a siren assembly of a vehicle alarm system. More particularly, the present invention relates to the siren assembly capable of generating multiple sound signals.
BACKGROUND
A vehicle alarm system (VAS) comprises of a siren assembly generally installed on a vehicle roof. The siren assembly of the vehicle alarm system produces a sound signal during occurrence of certain uncommon events. The uncommon events include, such as but not limited to, a major shock experienced by the vehicle, an unauthorized access to the vehicle, an unauthorized attempt to open vehicle door or vehicle boot area, and an unauthorized attempt to start the vehicle.
It is well-known that automotive industry standards (AIS) provides technical specifications for the VAS that imposes various constraints on the sound signal produced by the siren assembly, such that the sound signal is distinct, clearly audible, and recognizable by people present in the surrounding environment. Particularly, the automotive industry standards (AIS) defines a sound power, a passage frequency, and other parameter requirements for the sound signal generated by the siren assembly. The passage frequency is defined as the repetition rate of the pattern of the frequencies. For example, the automotive industry standards (AIS) defines passages of specified time of a instantaneous frequency range (i.e. 1800Hz to 3550Hz) with a passage frequency of 2Hz+/- of 1Hz (i.e. 1Hz to 3Hz), to be produced by the siren assembly. Therefore, the type of sound signal produced by the siren assembly, identified by people in the surrounding environment, have a period of 0.33 second to 1 second (derived by f=l/t).
Currently known siren assemblies employ an electronic circuit and a speaker. The electronic circuit produces an electrical signal that is amplified, processed, and

applied to a speaker. The speaker then produces a sound signal complying with the requirements of AIS. Particularly, the sound signal generated by the speaker is based on the electrical signal generated by the electronic circuit. The electric signal, generated by the electronic circuit of conventional siren assemblies, is a square wave whose instantaneous frequency varies in a periodic pattern. Particularly, the instantaneous frequency is a frequency at a particular instant.
Figure 1 shows a curve [100] depicting evolution of the instantaneous frequency of the electrical signal generated during a period of 500 ms (milliseconds), by the siren assembly. As seen in the figure 1, the instantaneous frequency of 1800Hz to 3500Hz of the electrical signal grows in portion tl. In the portion t2, the instantaneous frequency remains constant at 3500Hz. In the portion t3, the frequency decreases from 3500Hz to 1800 Hz and finally into the portion t4 remains constant at 1800Hz. Each portion (tl, t2, t3 and t4) has a duration of 125 ms.
Further, the electronic circuit of the currently known siren systems either use transistorized oscillators or digital gates that require acoustic pressure which is difficult to achieve and control. Further, the currently known siren systems using transistorized oscillators or digital gates produces a single tone only (only one electric signal and only one sound signal). The detailed implementation of the transistorized oscillators and digital gates used in the currently known siren systems is explained below.
Figure 2 illustrates an acoustic electronic circuit [200] that uses transistorized oscillators to produce the electrical signal similar to the police siren. When a push button switch S2 is pressed, a capacitor CI charges and this makes transistor Ql to turn ON slowly. When a switch SI is released, the capacitor CI gets discharged and the transistor Ql becomes OFF slowly. Further, when Ql is switched ON, its collector voltage falls and makes transistor Q2 ON, subsequent to which capacitor C2 gets charged almost to full supply voltage. This results in

an increase in collector-emitter voltage of the Q2. This change in voltage is coupled to the base of Ql via the capacitor C2. Thus, the transistor Ql comes slightly out of saturation, as a result of which, the collector voltage of Ql drops and makes the Q2 partially OFF. This action continues until both transistors become completely OFF. Then, the capacitor C2 discharges, and transistor Ql switches ON again to start a new cycle. Moreover, when the capacitor CI is charged, the tone rises and when the capacitor CI is discharging, the tone falls off.
Figure 3 illustrates a digital electronic circuit [300] that uses digital gates to produce an alarm. Four independent 2-input NAND gates of IC1 are depicted as a, b, c and d in figure 3. Two gates out of the four NAND gates are configured as low frequency oscillator and rest of the two NAND gates are configured as high frequency oscillator. Diode D2 conducts when output from low frequency oscillator is high and this conduction of the diode D2 enables high frequency oscillator. The value of capacitor C3 may be changed to 8 u.F in order to vary the speed of oscillator. Moreover, in this circuit, resistor Rl and capacitor CI are used as tone changer components. Sudden decaying of the output, when diode Dl ceases to conduct, is prevented by capacitor C2. Further, transistor Tl is used as speaker driver transistor.
In addition to above mentioned drawbacks, the required sound power of the siren assembly is between 100 dB to 125 dB, as per the AIS requirement. However, in the currently known sirens systems, the minimum level of 100 dB is difficult to achieve, especially with the siren assembly including a speaker. As apparent from the above description of known siren systems with reference to figures 2 and 3, the electronic circuit of the currently known siren systems either use transistorized oscillators or digital gates that require acoustic pressure which is difficult to achieve and control.

Therefore, in light of the above and other drawbacks and limitations of the currently known siren systems, it is essential to program an electronic circuit of the VAS in such a way to overcome the aforesaid problems in the currently known siren systems. The above-mentioned information in the background section is only intended to enhance the understanding of the reader with respect to the field to which the present invention pertains. Therefore, unless explicitly stated otherwise, any of the features or aspects discussed above should not be construed as prior art merely because of its inclusion in this section.
SUMMARY
In view of the drawbacks and limitations of the prior art systems, one object of the present invention is to provide systems and methods for providing a siren assembly for providing a sound signal of average sound power between 100 dB tol25dB.
Another object of the present invention is to provide a siren assembly for providing a sound signal significantly different from other audible signals.
Yet another object of the invention is to provide an electrical system of a siren assembly for producing a plurality of electrical signals in defined pattern and sequence. Each of the plurality of electrical signal corresponds to a predefined number of cycles, predefined number of steps, predefined number of pulses, predefined instantaneous frequencies range, and predefined passage frequency. Thereby, enabling the diaphragm assembly to produce a plurality of sound signals, corresponding to receipt of the plurality of electrical signals.
The present disclosure relates to a siren assembly, including a diaphragm assembly, an electrical system, and a propeller. The electrical system generates an electrical signal. The diaphragm assembly receives the electrical signal from the electrical system and generates a sound signal corresponding to the electrical signal. The sound signal is generated with an average sound power range of 110

Decibels to 125 Decibels. The diaphragm assembly outputs the sound signal through the propeller.
The present disclosure also relates to a method of producing a sound signal by a siren assembly. The siren assembly including a microcontroller, a signal circuit, and a diaphragm assembly. The method comprising a first step of, receiving, by the microcontroller, a siren initialization request in an event of an unauthorized access to a vehicle is detected. Then, the method includes a second step of selecting, by the microcontroller, an electrical signal from a plurality of electrical signals upon receipt of the siren initialization request. The method then includes a third step of retrieving, by the microcontroller, a tone information corresponding to the electrical signal. The tone information includes a predefined instantaneous frequency range, a predefined passage frequency, a predefined number of pulses, a predefined number of steps, and a predefined number of cycles, transmitting, by the microcontroller, a control signal to a signal circuit. The control signal corresponds to the tone information. The method thereafter includes a fourth step of generating, by the signal circuit, an electrical signal corresponding to the control signal. Thereafter, the method includes a fifth step of producing, by a diaphragm assembly, the sound signal, wherein the sound signal corresponds to the electrical signal received form the signal circuit.
BRIEF DESCRIPTION OF DRAWINGS
The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings. These and other details of the present invention will be described in connection with the accompanying drawings, which are furnished only by way of illustration and not in limitation of the invention, and in which drawings:

Figure 1 shows a curve depicting evolution of the instantaneous frequency of an electrical signal generated by the electronic circuit of currently known siren assemblies.
Figure 2 illustrates an acoustic electronic circuit using transistorized oscillators to produce a sound signal employed by the currently known siren assemblies.
Figure 3 illustrates a digital electronic circuit using digital gates to produce a sound signal employed by the currently known siren assemblies.
Figure 4 illustrates a cross-sectional view of a siren assembly, in accordance with an embodiment of the present invention.
Figure 5 illustrates a block diagram of an electrical system of the siren assembly, in accordance with an embodiment of the present invention.
Figure 6 illustrates a circuit diagram of the electrical system of the siren assembly, in accordance with an embodiment of the present invention.
Figure 7a illustrates a broad flow diagram of a method performed by the siren assembly for producing a sound signal, in accordance with an embodiment of the present invention.
Figure 7b illustrates a detailed flow diagram of the method performed by the siren assembly for producing the sound signal, in accordance with an embodiment of the present invention.
Figure 8 illustrates a graph showing sound power as a function of the frequency of the sound signal produced by the siren assembly, in accordance with an embodiment of the present invention.
Figure 9 illustrates a curve depicting evolution of the instantaneous frequency of the electrical signal produced by the electrical system of the siren assembly, in accordance with an embodiment of the present invention.

Figure 10 illustrates a graph of the sound pressure of the siren assembly controlled, in accordance with an embodiment of the present invention.
Figure 11 illustrates a graph of sound pressure for the sound signal produced by the siren assembly, in accordance with an embodiment of the present invention.
Figure 12 illustrates a curve depicting evolution of the instantaneous frequency of the electrical signal produced by the electrical system of the siren assembly, in accordance with another embodiment of the present invention.
Figure 13 illustrates a square electrical signal generated by the electrical system of the siren assembly, in accordance with an embodiment of the present invention.
Figure 14 illustrates the electrical signal transmitted at the terminals of the diaphragm assembly of the siren assembly, in accordance with an embodiment of the present invention.
Figure 15 illustrates a graph plotted for produced instantaneous frequency with respect to time of the electrical signal produced by the electrical system of the siren assembly, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that the disclosed embodiments may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. However, any individual feature may not address any of the problems discussed above or might address only some of the problems discussed above in the background section. Some of the problems discussed above might not be fully addressed by any of the features described herein.

The present invention encompasses systems and methods for providing a siren assembly of the vehicle alarm system, for producing a sound signal. As used herein, a 'vehicle' refers any kind of transport vehicle used on road that transports people or cargo. Vehicle may include, but are not limited to, cars, trucks, buses, ambulances, two-wheelers, and any other vehicles obvious to a person skilled in the art.
Figure 4 illustrates a cross-sectional view of the siren assembly of the VAS. The siren assembly [400] is structured and programmed to be capable of producing a plurality of sound signals. Each of the plurality of sound signals is distinguished from each other based on a sound information for each of the plurality of sound signals. The sound information including an instantaneous sound frequency range, a sound passage frequency, a number of sound pulses, a number of sound steps, and a number of sound cycles, for each of the plurality of sound signals. The siren assembly [400] comprises of, a propeller [402], a diaphragm assembly [404], and an electrical system [406]. The siren assembly [400] of the VAS is powered by a 12V battery of the vehicle, wherein power provided by the vehicle battery is further provided to the electrical system [406] and the diaphragm assembly [404].
The electrical system [406] is a combination of an electronic circuit [602] and a programmed microcontroller. The electrical system [406] is designed for producing a plurality of electrical signals, for enabling the diaphragm assembly [404] for producing the plurality of sound signals. Each of the plurality of electrical signals is distinguished from each other based on a tone information for each of the plurality of sound signals. The tone information including an instantaneous frequency range, a passage frequency, a number of pulses, a number of steps, and a number of cycles. Further, the electrical system [406] produces an electrical signal selected from the plurality of electrical signals, and transmits to the diaphragm assembly [404]. The diaphragm assembly [404] then

generates a plurality of sound signals corresponding to the plurality of electrical signals, received from the electrical system [406].
Furthermore, it may be noted that each of the plurality of electrical signals corresponds to defined frequencies and defined sequence (as discussed in figure 7). Notably, the electrical signal is periodic, such that each period of the produced electrical signal comprises of at least a portion of a rising frequency (i.e. frequency rising from low to high), at least a portion downlink frequency (i.e. frequency goes from higher to lower), at least a portion of constant high frequency, and at least one portion with constant low frequency. In a preferred embodiment, the minimum frequency is 1800 Hz and the maximum frequency is 3500Hz. Preferably, the period for each of the aforementioned portions is between 0.33s and Is. Further, the at least one portion to downlink frequency and the rising frequency, is such that the instantaneous frequency goes through a resonant frequency of the diaphragm assembly [404]. The resonant frequency is the frequency at which the overall electrical and mechanical assembly generates maximum output of dB level sound. According to a preferred embodiment, the predefined frequency range is the range of 1800Hz to 3550Hz.
The diaphragm assembly [404] comprises of a transducer that receives one of the plurality of electrical signals from the electrical system [406]. On receiving the electrical signals from the electrical system [406], the diaphragm assembly [404] starts vibrating causing the diaphragm assembly [404] to produce a sound signal of desired frequency and sound pressure Level (SPL). Moreover, the sound signal is dependent on the electrical signal received form the electrical system [406]. Particularly, the frequency produced by the sound signal produced by the diaphragm assembly [404] is dependent on the electrical signal generated by the electrical system [406]. A change in the electrical signal produced by the electrical system [406], corresponds to a change in the sound signal produced by the diaphragm assembly [404]. Advantageously, the sound signal produced by

the diaphragm assembly [404] has an average sound pressure level (SPL) of between 100 dB to 125 dB. In a particular embodiment, the resonance frequency is obtained by exciting a transducer of the diaphragm assembly [404] with determined amplitude at a plurality of frequencies in the frequency range and by retaining a frequency of the plurality of frequencies for which the acoustic power radiated by the diaphragm assembly [404] reaches a maximum level.
The propeller [402] enables the air to come out of the diaphragm assembly [404] with maximum sound. In particular, the sound signal produced by the diaphragm assembly [404] comes out in the surrounding environment with the help of the propeller [402].
Figure 5 illustrates a block diagram of the electrical system [406] of the siren assembly [400]. The electrical system [406] comprises of a power supply section [502], a tone generation section [504], and an amplifier [506]. The output of the electrical system [406] is utilized by a diaphragm assembly [404] to produce desired sound. Moreover, all of these blocks of the electrical system [406] along with the diaphragm assembly [404] of the siren assembly [400] is enclosed in an outer casing [510]. The casing [510] protects the siren assembly [400] from water, dust, moisture etc. Further, casing [510] is capable of handling harsh vehicle environment and vibrations in an engine compartment of the vehicle.
The power supply section [502] is connected to a battery/the electrical system [406] of the vehicle through wires (not show in figure 5). Further, the battery/ electrical system [406] of the vehicle provides power to the power supply section [502] that in turn provides power to the tone generation section [504] and the amplifier [506].
The tone generation [504] comprises of an electronic circuit [602] and a microcontroller [604] (not shown in figure 5) having memory and programmed, to generate an electrical signal selected from the plurality of electrical signals. The plurality of electrical signals correspond to producing of the plurality of

sound signals. Particularly, each electrical signal corresponds to producing of a sound signal, where each sound signal has a specific tone specification. The tone specification includes, but is not limited to, a predefined instantaneous frequency range, a predefined passage frequency, a predefined number of pulses, a predefined number of steps, and a predefined number of cycles. Further, the microcontroller [604] has a memory for storing control parameters for each tone such as minimum frequency, maximum frequency, a stationary frequency (i.e. the frequency if remains same for some time in some tone combination), a time passage and a holding time, etc. Based on these parameters, a tone is generated.
The electrical system [406] operates on 5V or less and thus, generates the electrical signal selected form the plurality of electrical signals having less power that is not sufficient to vibrate the diaphragm assembly [404]. Amplifier [506] amplifies the electrical signal generated by the electrical system [406] to increase power (to 12V) of the electrical signal sufficient enough to vibrate the diaphragm assembly [404]. Then, the amplified electrical signal vibrate the diaphragm assembly [404]. Further, the diaphragm assembly [404] produces the sound signal, corresponding to the electrical signal received.
Figure 6 illustrates a circuit diagram [600] of the electrical system [406] of the siren assembly [400], in accordance with an embodiment of the present invention. The electrical system [406] comprises of an electronic circuit [602] in form of a push pull type of amplifier, and a microcontroller [604]. The electronic circuit [602] includes all the electronics shown excluding the microcontroller [604]. The microcontroller [604] controllably supplies a number of pulses (a combination of the number of pulses is referred to as a control signal) to the electronic circuit [602] in defined sequence, to enable the electronic circuit [602] to produce the electric signal selected from the plurality of electrical signals. Particularly, the microcontroller [604] controllably drives Q6-Q1-Q5 ON and Q3-

Q2-Q4 OFF in a half cycle of the frequency, providing current in the coil TP14 positive and TP15 negative. Moreover, the microcontroller [604] drives Q6-Q1-Q5 OFF and Q3-Q2-Q4 ON, in second half cycle of the frequency, providing the current in reverse direction to the coil. i.e. TP15 positive and TP14 Negative. Such controlled activations/ deactivation of TP15 and TP14, corresponds to generation of the electrical signal by the electronic circuit [602]. Notably, the microcontroller [604] stores the tone specification for the plurality of sound signals. Moreover, the microcontroller [604] is programmed to controllably supply the number of pulses to the electronic circuit [602] (a combination of the number of pulses is referred to as a control signal), such that the electronic circuit [602] produces the electrical signal selected from the plurality of electrical signals, and thereby the diaphragm assembly produces the sound signal corresponding to the plurality of sound signals. Such manipulation, by the microcontroller [604], is done based on a method of producing the sound signal.
With respect to figure 7a, a broad flow chart of the method of producing the sound signal by the siren assembly is described.
At step 700a, the microcontroller [604] receives a siren initialization request in an event of an unauthorized access to a vehicle is detected. Particularly, in an event of unauthorized access to the vehicle, a sensing unit generates the siren initialization request, which is received by the microcontroller [604].
At step 700b, the microcontroller [604] selects a sound signal from a plurality of sound signals upon receipt of the siren initialization request.
At step 700c, the microcontroller [604] retrieves a tone information (or tone specification) corresponding to the sound signal, wherein the tone information includes the predefined instantaneous frequency range, the predefined passage frequency, the predefined number of pulses, the predefined number of steps, and the predefined number of cycles.

At step 700d, the microcontroller [604] transmits a control signal to the electronic circuit [602]. The control signal is based on the tone information. Particularly, the transmittal of the control signal, by the microcontroller [604], is done by initially transmitting a first pulse signal to the electronic circuit [602]. Thereafter, transmitting a second pulse signal after a delay of corresponding to the predefined passage frequency. Thus, repeatedly performing the steps of transmitting the first pulse signal and the second pulse signal, based on the tone information. Particularly, repetition of the steps of transmitting the first pulse signal and the second pulse signal is done based on the number of cycles, the number of steps, and the number of pulses of the selected sound signal. A combination of these pulses is referred to as the control signal. Such introduction of delay between the first pulse and the second pulse, enables the desired passage frequency in the control signal. Also, such repetition of the steps of transmitting the first pulse signal and the second pulse signal, enables the introduction of the predefined number of pulses, the predefined number of steps, and the predefined number of cycles in the control signal.
At step 700e, the electronic circuit [602] generates an electrical signal corresponding to the control signal. Particularly, the frequency of the electrical signal generated by the electronic circuit [602] is based on the frequency of the control signal received form the microcontroller [604]. Thereby, the predefined passage frequency, the predefined number of pulses, the predefined number of steps, and the predefined number of cycles, are introduced in the electrical signal of the electronic circuit [602].
At step 700f, a diaphragm assembly [404] produces the sound signal. The sound signal corresponds to the electrical signal received from the electronic circuit [602]. Particularly, the diaphragm assembly [404] is thereby enabled to produce the sound signal of the tone information of the selected sound signal, corresponding to controller manipulation of the electronic circuit [602] by the

microcontroller [604]. More specifically, the diaphragm assembly [404] produces the sound signal of predefined instantaneous frequency, the predefined passage frequency, the predefined number of pulses, the predefined number of steps, and the predefined number of cycles.
With respect to figure 7b, a detailed flow diagram [700] is provided that is implemented by the siren assembly [400] to produce the sound signal of defined tone specification, in accordance with an embodiment of the present invention.
At step 702, the electrical system [406] initializes on receiving power from the power supply section [502]. The power to the electrical system is transmitted upon generation of a siren initialization request by a sensing unit during an attempt of unauthorized access to the vehicle. The supply of power to the electrical system [406] activates the microcontroller [604] of the electrical system [406].
At step 704, once the microcontroller [604] of the electric system [406] is initialized, the microcontroller [604] of the electric system [406] selects at least one tone from a plurality of tones stored in the memory of the microcontroller [604] of the siren assembly [400]. Particularly, the microcontroller [604] of the electric system [406] selects at least one sound signal from a plurality of sound signals stored in the memory of the microcontroller [604].
At step 706, once the sound signal is selected from the plurality of sound signals, the microcontroller [604] of the electric system [406] retrieves number of cycles of the selected sound signal.
At step 708, once the number of cycles are retrieved, the microcontroller [604] of the electric system [406] retrieves number of steps in each retrieved cycle of the selected sound signal.

At step 710, once the number of steps in each cycle are retrieved, the microcontroller [604] of the electric system [406] retrieves number of pulses in each retrieved step of the selected sound signal.
At step 712, once the number of pulses are retrieved, the microcontroller [604] of the electric system [406] retrieves passage frequency in each retrieved pulse of the selected sound signal.
At step 714, the microcontroller [604] compliments the output voltage of the electrical signal at the electronic circuit [602]. In particular, if the output voltage of the electrical signal at the electronic circuit [602] of the selected sound signal is 0V, then the microcontroller [604] compliments the voltage to 12V and vice-versa. This complementing of output voltage helps in done by sending a pulse signal, which enables the electronic circuit [602] to produce the electrical signal.
At step 716, the microcontroller [604] of the electric system [406] delays as per the frequency of next selected tone by a pre-determined duration of time (derived through f=l/t). The delay corresponds to the passage frequency of the selected sound signal.
At step 718, the microcontroller [604] of the electric system [406] increments pulse number of a particular step of the selected sound signal.
At step 720, the microcontroller [604] of the electric system [406] determines if all the pulses of a particular step in particular cycle gets completed. If all the pulses of a particular step in particular cycle gets completed, then the microcontroller [604] of the electric system [406] proceeds to next step 722, otherwise proceeds to step 714.
At step 722, the microcontroller [604] of the electric system [406] increments step number of a particular cycle of the selected sound signal.
At step 724, the microcontroller [604] of the electric system [406] determines if all the steps in a particular cycle are completed. If all the step in particular cycle

gets completed, then the microcontroller [604] of the electric system [406] proceeds to next step 726 otherwise proceeds back to step 712.
At step 726, the microcontroller [604] of the electric system [406] increments cycle of the selected tone.
At step 728, the microcontroller [604] of the electric system [406] determines if all the steps in particular cycle are completed. If all the step in particular cycle gets completed, then the microcontroller [604] of the electric system [406] proceeds to select next sound signal otherwise proceeds to step 710.
In the similar way, the siren assembly [400] produces the plurality of sound signals with different tone specification, particularly defined cycles, steps, pulses and frequencies. In a preferred embodiment, the siren assembly [400] produces six different tones having different defined cycles, steps, pulses and frequencies.
The table below describes the number of cycles, number of steps in each cycle, total number of pulses, frequency range in kHz, and passage frequency in Hz required to generate six tones.

Tone Number of Cycles Number of Steps in Each Cycle Total Hum ber of Pulses Frequency Range in kHz Passage frequency in Hertz
Tone 1 22 :6 11264 1.99~2.S5KHz 2.B505
Tone 2 b 47 11520 2.15-3.45KHz 1.34B1
Tone 3 IS 7 6912 1.99-2.75*4! 2.B460
Tone 4 3 30 11430 2J)2~2.85KHs 1J0253
Tone 5 14 S 8960 1.99-2 .S5KHs 2.9S05
Tone & 9 36 4536 2JQ4-2.82KH2 1.9937
As shown in figure 8, a graph [800] is illustrated showing acoustic power of the siren assembly [400] as a function of the frequency of the produced sound signals, in accordance with an embodiment of the present invention. The graph [800] illustrated is achieved by measuring the siren assembly [400] output (Y axis) with respect frequency (X axis).

Figure 9 illustrates a curve [900] depicting evolution of the instantaneous frequency of the electrical signal, in accordance with an embodiment of the present invention. This curve depicts frequency (Y axis) with respect to time (X axis).
Figure 10 illustrates graph [1000] of sound pressure of the siren assembly [400] controlled as shown in Figure 4, in accordance with an embodiment of the present invention.
Figure 11 illustrates graph [1100] of sound pressure for a tone generated by the siren assembly [400] as shown in Figure 4, in accordance with an embodiment of the present invention.
Figure 12 illustrates a curve [1200] depicting evolution of the instantaneous frequency of the electrical signal produced by the electrical system [406], in accordance with another embodiment of the present invention.
Figure 13 illustrates square electrical signal [1300] formed by the electrical system [406] of figure 6, in accordance with an embodiment of the present invention. The signal shown is the actual electrical signal generated by the siren assembly [400] and is shown on an oscilloscope. The electrical signal [1300] is depicted on the oscilloscope in terms of time and voltage.
Figure 14 illustrates a control signal corresponding to the terminals of the transducer of the siren assembly [400], in accordance with an embodiment of the present invention. The graph [1400] is plotted for current flowing with respect to time.
Figure 15 illustrates a graph [1500] plotted for produced frequency with respect to time of the electrical signal produced by the electrical system [406] of the siren assembly [400], in accordance with an embodiment of the present invention.

In accordance with the aforementioned points, it may be noted that the usage of the diaphragm assembly [404] and the propeller [402] in the siren assembly, enables the siren assembly to produce the sound signal within a sound power range of 100 DB to 125 Db. Further, the usage of the microcontroller [604] with the electronic circuit enables the electrical system to produce a varied range of the electrical signals, which enables the diaphragm assembly to produce a varied range of the sound signals. Moreover, such method of producing the sound signal is energy efficient.
While the present invention has been described with reference to certain preferred embodiments and examples thereof, other embodiments, equivalents and modifications are possible and are also encompassed by the scope of the present disclosure. Although the invention has been described with reference to vehicles, however, it will be appreciated by those skilled in the art that the vehicle alarm systems may be applicable to other alarm systems.
List of Components:
100 - Frequency Curve of Electrical Signal produced by conventional Siren Assemblies
200 - Acoustic Electronic Circuit of conventional Siren Assemblies
300 - Digital Electronic Circuit of conventional Siren Assemblies
400 - Siren Assembly
402-Propeller
404 - Diaphragm Assembly
406- Electrical System
502- Power Supply
504 - Tone Generation Section

506-Amplifier
510- Casing
600 - Circuit Diagram of Electrical System
602 - Electronic Circuit
604 - Microcontroller
700a-700f-Broad Steps of method of producing sound signals
700b - Detailed Flow Diagram of method of producing sound signals
702-728-Steps of 700b

We Claim:
1. A siren assembly [400], comprising:
a diaphragm assembly [404];
- a propeller [402];
an electrical system [406] for generating an electrical signal, wherein
the diaphragm assembly [404] receives the electrical signal from the electrical system [406] and generates a sound signal corresponding to the electrical signal, such that the sound signal is generated with a sound power range of 110 Decibels to 125 Decibels,
the diaphragm assembly [404] outputs the sound signal through the propeller [402].
2. The siren assembly [400] as claimed in claim 1, wherein the electrical
system [406] comprises of:
an electronic circuit [602] capable of producing a plurality of electrical signals; and
a microcontroller [604] adapted to manipulate the electronic circuit, such that the electronic circuit [602] produces one of the plurality of electrical signals, thereby enabling the diaphragm assembly [404] for producing one of the plurality of sound signals.
3. The siren assembly [400] as claimed in claim 2, wherein each of the plurality of electrical signals corresponds to a different combination of a predefined instantaneous frequency range, a predefined passage

frequency, a predefined number of pulses, a predefined number of steps, and a predefined number of cycles.
4. The siren assembly [400] as claimed in claim 2 and claim 3, wherein the microcontroller [604] transmits a control signal to the electronic circuit [602], such that the electronic circuit [602] produces one of the plurality of electrical signals and thereby the diaphragm assembly [404] produces one of the plurality of sound signals.
5. A method of producing a sound signal by a siren assembly [400], the siren assembly [400] including a microcontroller [604], an electronic circuit [602], and a diaphragm assembly [404], the method comprising:
receiving, by the microcontroller [604], a siren initialization request in an event of an unauthorized access to a vehicle is detected;
selecting, by the microcontroller [604], an electrical signal from a plurality of electrical signals upon receipt of the siren initialization request;
retrieving, by the microcontroller [604], a tone information corresponding to the electrical signal, wherein the tone information includes a predefined instantaneous frequency range, a predefined passage frequency, a predefined number of pulses, a predefined number of steps, and a predefined number of cycles;
transmitting, by the microcontroller [604], a control signal to the electronic circuit [602], wherein the control signal is based on the tone information;
generating, by the electronic circuit [602], an electrical signal corresponding to the control signal;

producing, by the diaphragm assembly [404], the sound signal, wherein the sound signal corresponds to the electrical signal received from the electronic circuit [602].
6. The method as claimed in claim 5, wherein the step of transmitting the control signal to the electronic circuit [602] includes:
transmitting a first signal to the electronic circuit [602];
transmitting a second pulse signal to the electronic circuit [602], after a delay corresponding to the predefined passage frequency;
repeatedly performing the steps of transmitting the first pulse signal and the second pulse signal, based on the tone information.