Technical Field
This disclosure generally relates to a system for silently communicating a horn-signal from one vehicle to another vehicle, and more particularly relates to a transmitter configured to transmit a horn-signal
Background
In vehicles, acoustic horns such as high dB (decibel) horns are being used since ages to alert the vehicles ahead of a driving-vehicle. Drivers honk their vehicles for a variety of reasons, for example, because of slow moving car or stalled traffic ahead of them, to get the attention of another, or for other reasons. If a driver had knowledge of what is going on, for example, in the surrounding area that is causing the slow down or traffic stall, the driver might not need to honk as much. However, impatience and confused state during driving conditions usually compel the driver to honk to the maximum.
Yet, such incessant or intermittent usage of horns leads ends us causing grave noise-pollution, especially within the urban-environment. The art of driving a motor vehicle in the process in order to alert other vehicles, are used in audio speakers tweet, in such a way to bring serious noise pollution, especially causes a lot of noise pollution.
On the other hand, usage of acoustic horn is many-a-times inevitable for example for sending alert in catastrophies and accidental-scenarios. Yet, usage of same is legally-prohibited in many zones/areas and invites penal-consequences. For example, some cities or specific city-zones such as hospitals/schools/colleges have restrictions over usage of acoustic-horns. Accordingly, since the vehicle user is bound by law to not blow the horn in such specific city-zones, there may be no other alternative-mechanism in the vehicle to provide alerts to surrounding vehicles. The problem worsens especially where the signalling of the alerts to surrounding vehicles is inevitable to prevent accidents.

Accordingly, there lies at least a need to provide a mechanism to render alerts from one vehicle to another without causing any effect upon a third party.
More specifically, there lies at least a need to provide a mechanism to render alerts from one vehicle to another, such that the effects of alerts upon the outside-environment are null.
Summary of Invention
This summary is provided to introduce a selection of concepts in a simplified version that is further described below in the detailed description. This summary is not intended to identify key features or essential features of the present invention, nor is it intended as an aid in determining the scope of the present invention.
The present subject matter describes a system for communicating a radio-signal for generating a horn. The system comprises an oscillator for generating a low-power signal at a pre-determined frequency based on triggering by a user-operable switch. A semiconductor switching element based gate-driver circuit is provided for driving a power semiconductor-switch based on the low-power signal and thereby switching ON the power semiconductor-switch. A transmitter is provided for transmitting a modulated radio-signal based on the switched ON state of the semiconductor-switch and in accordance with said predetermined frequency to enable generation of a sound of a predetermined decibel (dB) level of an acoustic horn at a receiver end.
Further, the present subject matter describes a system for wirelessly-receiving signal for generating a horn and controlling thereto. The system comprises a receiver-circuit configured for receiving and demodulating a received radio-signal. A voltage-reduction mechanism is provided for rendering a reduced power-supply. A differential-amplifier is provided for receiving the demodulated-signal and the reduced power-supply to generate a horn based audible-sound of a predetermine decibel (dB) level. A manually operable delay circuit is provided to delay an operation of the differential-amplifier by a predetermined time to stop said generation of sound.

The present subject matter at least renders a method of mitigating honking and thereby minimize noise-pollution. The method, in one aspect, may comprise detecting a non-audible horn signal (e.g. Infra-red signal) within a vehicle by a receiver (e.g. Infra-red receiver) and thereby sounding a buzzer based on said detection. The method may also comprise generating such non-audible signal based on the activation of the horn-switch within a vehicle and transmitting the same wirelessly as an electromagnetic-signal for irradiating the one or more receiver within one or more neighbouring-vehicles. The method may also comprise transmitting the non-audible signal to at-least one targeted-recipient device.
The advantages and details of the present invention will be apparent from the following detailed description and accompanying drawings, which are explanatory only and is not restrictive of the present invention.
Brief Description of the Accompanying Drawings
To further clarify the advantages and features of the present invention, a more particular description of the present invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the present invention and are therefore not to be considered limiting of its scope. The present invention will be described and explained with additional specificity and detail with the accompanying drawings in which:
Figure 1 illustrates a networking environment for silently communicating a horn-signal between vehicles, in accordance with the present subject matter;
Figure 2 illustrates a block-diagram representation of the transmitter circuit or an assembly of the transmitter (Tx) for transmitting the signal, in accordance with the present subject matter;

Figure 3 illustrates an example implementation of a transmitter-circuit to implement the present invention, in accordance with the present subject matter;
Figure 4 illustrates a block-diagram representation of the receiver circuit or an assembly of the receiver (Rx) within the receiving vehicle for receiving the signal, in accordance with the present subject matter; and
Figure 5 illustrates an example implementation of a receiver-circuit to implement the present invention, in accordance with the present subject matter.
It may be noted that to the extent possible like reference numerals have been used to represent like elements in the drawings. Further, those of ordinary skill in the art will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of aspects of the present invention. Furthermore, the one or more elements may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefits of the description herein.
Detailed Description
For the purpose of promoting an understanding of the principles of the present invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the present invention as

illustrated therein being contemplated as would normally occur to one skilled in the art to which the present invention relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the present invention and are not intended to be restrictive thereof. Throughout the patent specification, a convention employed is that in the appended drawings, like numerals denote like components.
Reference throughout this specification to "an embodiment", "another embodiment" or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems. Various embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
Figure 1 illustrates a networking environment 100 for silently communicating a horn-signal 101 between vehicles such as automobiles, trucks, motorcycles, etc. In this non-limiting example, the vehicle comprises a vehicle or passenger-car 102 that transmits the horn-signal 101, and a receiving-vehicle 104-1, 2, 3 which receives or detects the horn-signal 101. In order for the horn-signal 101 to be silently communicated between vehicles, the horn-

signal is transmitted using electromagnetic-energy such as infrared-light (IR) energy. That is, the horn-signal 101 is characterized as being silent because a human-being cannot hear directly with ears the transmitted electromagnetic-energy. In other words, the horn-signal 101 is not acoustic in nature so cannot be directly heard by human-beings without some intervening apparatus, e.g. an IR receiver. By using electromagnetic-energy to transmit the horn-signal 101, the problem of noised pollution caused by the operation of acoustic horns on vehicles is addressed.
A fundamental frequency of the IR signal used to transmit the horn-signal 101 may be selected based on a desired-transmission distance and resistance to being obstructed by expected objects present between the sending-vehicle 102 and the receiving-vehicle 104.
The sending-vehicle 102 is equipped with a horn-button operable by the operator of the sending-vehicle 102. In an example, the horn-button is illustrated as being located on a steering-wheel of an automobile. However, other locations are possible. Further, the sending-vehicle 102 is also equipped with a transmitter (Tx) configured to transmit the horn-signal 101 using electromagnetic-energy. That is, as noted above, the horn-signal 101 is not comparable to the audible horn sound emitted by a traditional horn and accordingly an in-audible radio signal. The transmitter (Tx) transmits the horn-signal 101 in response to the horn-operator operating the horn-button.
In an example, the sending-vehicle 102 is also equipped with a first location-device such as a global-positioning-sensor (GPS), or other navigation device known to those in the art. The first location-device is configured to determine a send-location of the sending-vehicle 102. Accordingly, the send-location of the sending-vehicle 102 can be determined by the receiving-vehicle 104. As used herein, to incorporate the send-location into the horn-signal means that the information represented by the send-location is encoded into the horn-signal 101.

The receiving-vehicle 104, which is understood to be different or distinct from the sending-vehicle 102, is equipped with a receiver configured to detect the electromagnetic or IR horn-signal 101 and accordingly sound a buzzer, thereby acoustically alerting the operator of the receiving vehicle 104 about the sending vehicle 102. In addition, the receiving vehicle 104 may also display a location of the sending vehicle 102 based on the detected IR signal.
Figure 2 illustrates a block-diagram representation of the transmitter circuit or an assembly 200 of the transmitter (Tx) within the sending vehicle 102 for transmitting the signal 101. More specifically, transmitter assembly 200 comprises a power supply 202 which may be a vehicle battery. A switch SI may be a manually operable horn-switch as provided for triggering generating a non-audible horn-signal. Upon its actuation, the switch SI energises the present assembly 200 through the power supply.
Further, a multi-vibrator 204 is provided as an electronic-oscillator circuit that produces a pre-determined non-sinusoidal/sinusoidal repetitive output signal to generate oscillations or frequency. Said frequency ranges from several Khz to more than several hundreds of Khz. The multi-vibrator 204 may be gatable astable-multivibrator with logic techniques incorporated to permit positive or negative edge triggered monostable-multivibrator action with retriggering and external counting options.
Further, a driver circuit 206 is connected to the power supply 202 and the multi-vibrator 204. The driver circuit 206 comprises semiconductor elements and is a gate-driver or a MOSFET drive circuit that provides an ability to apply a voltage sufficiently higher than Vu, (threshold voltage) to the gate of the driven MOSFET and a drive capability to sufficiently charge the input capacitance with respect to a driven MOSFET. The gate-driver accepts a lower-power input at the pre-determined frequency from the multi-vibrator 204 and produces a high-current drive input for the gate of a power MOSFET 208.

The transistor switch 208 is a voltage-driven device and in an example may be a MOSFET. The gate driver 206 subjects the switch 208 or a MOSFET 208 with a voltage higher than the rated gate-threshold voltage Vth as applied to the gate of the MOSFET 208. The MOSFET 208 is used as a semiconductor 'switching-device' in accordance with a frequency as generated by the multi-vibrator 204.
Further, an IR transmitter 210 is provided at the output of the MOSFET 208. The switching of the MOSFET 208 energises the infra-red (IR) transmitter 210 in accordance with the multi-vibrator frequency. The IR transmitter 210 emits IR radiation modulated at a particular-frequency.
Figure 3 (a till c) illustrates an example implementation of a transmitter-circuit 300 to implement the present invention. As mentioned before, the circuit 300 in Fig. 3a is designed to transmit an alert-signal from the sender-vehicles 102 to the ahead or receiving vehicles 104.
In an example, the circuit 300 comprises a 12 volt input as the power supply 202, an IR transmitter, a multi-vibrator IC (CD4047), and metal oxide semiconductor field effect transistor (MOSFET). The multi-vibrator 204 may be a multi-vibrator IC (CD4047) acting as the astable, monostable or bistable multi-vibrator.
A driver circuit 206 may be of push-pull configuration comprising NMOS (Ql) and PMOS transistors (Q2), respectively. Ql may be connected to power-supply and Q2 may be grounded. In other example, the driver circuit 206 comprises MOSFETs in a CMoS inverter configuration comprising said NMOS and PMOS.
The MOSFET 208 is an NMos that is gate-driven by the driver circuit 206, which is provided in the push-pull configuration. The source terminal of the MOSFET 208 is connected to power supply and drain is connected to an IR transmitter 212 to energise the transmitter 208 at a predetermined-frequency. Further, the MOSFET 208 or NMos 208 operates in active mode of

operation upon having been triggered by the driver 206 and accordingly energises the IR transmitter 212.
In an example, the IR transmitter 212 is a group of IR LEDs 212 (IR1, IR2, IR3). configured to emit IR radiation upon energization.
In operation, when user presses the switch SI, multi-vibrator IC 204 gets enabled and passes a signal to the driver circuit 206 (Ql and Q2). This drives the MOSFET 208, thereby completing the circuit to transmit alert signal through IR transmitter 210 (IR1, IR2, IR3). The number of IR sensors can be increased or decreased as per requirement.
Fig. 3b illustrates a "Horn-circuit" forming a sub-circuit within the circuit 300 of Fig. 3a. More specifically, Fig. 3b illustrates an implementation of the horn circuit forming a part of the Fig. 3 a and accordingly represents a variant of the Horn Circuit as depicted in Fig. 3 a.
Likewise, Fig. 3c illustrates an "infra-red transmitter circuit" forming a "sub-circuit" within the circuit 300 of Fig. 3a. More specifically, Fig. 3b illustrates an implementation of the horn circuit forming a part of the Fig. 3a and accordingly represents a variant of the Horn-Circuit as depicted in Fig. 3a. The gate driver arrangement in the present figure comprises NMoS (Q2) and PMoS (Q4) configured in a push-pull configuration to drive the gate of power MOSFET Q3.
In operation, when user presses the switch SI of the horn circuit of Fig. 3b, the multi¬vibrator IC 204 therein gets enabled and passes a signal with a particular frequency (tuned in line with the receiver-circuit) to a driver circuit 206 (Q2 and Q4) forming a part of the IR transmitter circuit of Fig. 3c. This drives the power MOSFET 208 or MOSFET Q3 of Fig. 3c, thereby completing the circuit to transmit alert signal through IR transmitter 210 (IR1, IR2, IR3).
Figure 4 illustrates a block-diagram 400 representation of the receiver circuit or an assembly 400 of the receiver (Rx) within the receiving vehicle 104 for receiving the signal 101.

More specifically, the receiver assembly 400 comprises a power supply 402 which may be a vehicle battery.
The power supply 402 powers an IR receiver 406 through a voltage regulation arrangement 404. The voltage regulator 404 renders a constant voltage to the IR receiver 406. Upon receiving the IR transmission which is modulated signal, the IR receiver 406 demodulates the same and sends it to a comparator 408.
A comparator 408 is powered by the power-supply 402 and receives the output from the IR receiver 406 at its non-inverting terminal (+). The inverting end (-) of the comparator 408 receives the power supply 402 at a reduced voltage rendered through a voltage divider arrangement 412 comprising a parallel configuration of resistors. The comparator 408 compares amplitude of non-inverting end input (say VI) with the amplitude of signal at the non-inverting terminal (say V2). In case V1>V2, the comparator 408 outputs a logic 1 (HIGH) and energises the buzzer 414 to sound an alarm or hooter within the receiving vehicle 104.
Another part of the present circuit comprises a switch S2 which is a manually operable-switch. Said switch connects/disconnects the power supply 402 to a timer 410. Upon the actuation of said switch S2, the timer 410 delays the operation of the comparator 408 and accordingly delays the output from reaching the buzzer 414 by a pre-determined time interval. Accordingly, the actuation of switch S2 leads to silence of the buzzer 414 for a pre-defined time and accordingly overrides the end-result of the receipt of the IR signal for a pre-determined time.
Figure 5 (a to d) illustrates an example implementation of a receiver-circuit 500 to implement the present invention. As mentioned before, the circuit 500 is incorporated within the receiving-vehicles 104 to receive an alert-signal from the sender-vehicles 102. More specifically, Fig. 5 illustrates the receiver and buzzer circuit with respect to the present invention.

Fig. 5a illustrates the overall circuit 500 that is designed to receive the alert signal to switch ON the buzzer. For this purpose, the circuit 500 comprises of 12V DC power-supply 402. The voltage regulator (Ul) 404 may be a voltage regulator IC (7805 IC) that maintains the output voltage at a constant value. Bypass capacitors (C3 and C4) may be provided to filter the AC ripple.
The IR receiver 406 may be a TSOP 1738 comprising Photo Detector, Gain Control, Band Pass Filter, Demodulator and a Pre-amplifier in a single package and compatible with all types of transmission codes supporting different modulating techniques like RC6, RC5, NEC, Sony, etc. TSOP 1738 in particular supports a carrier frequency of 38 KHz and has three pins namely GND, VS and OUT.
The timer 410 may be a TSOP 173 555 timer IC and the comparator 408 may be an op-amp (operational amplifier) incorporated in "Comparator" configuration.
In operation, a first alert-signal is received by the IR receiver 406. Upon such receipt, the IR receiver 406 sends output to the non-inverting pin of the comparator 408 and on the inverting pin a 12V signal through the voltage divider 412. The logic HIGH or logic '1' activates the buzzer 414, alerting the driver in the receiving vehicle 104. To temporarily stop the buzzer 414, the driver actuates switch S2. Such action connects the timer IC 555 with the circuit 500 and accordingly delays the output from the comparator 408 towards the buzzer 414, say by 13 seconds. Accordingly, the circuit 500 remains OFF for an adjustable time period (for example 13 seconds) and starts again in case alert-signal is still being received at the receiver 406. In other example, the adjustable time period may be a fixed time period.
Fig. 5b illustrates a "signal-receiving circuit" or a receiver forming a sub-circuit within the circuit 500 of Fig. 5a. More specifically, Fig. 5b illustrates an implementation of the receiver forming a part of the Fig. 5a and accordingly represents a variant of the circuit as depicted in Fig. 5 a.

Fig. 5 c illustrates a "buzzer control circuit" forming a sub-circuit within the circuit 300 of Fig. 5a. More specifically, Fig. 3c illustrates an implementation of the "buzzer control" forming a part of the Fig. 5a and accordingly represents a variant of the circuit as depicted in Fig. 5a.
Likewise, Fig. 5d illustrates a "timing or delay circuit" forming a "sub-circuit" within the circuit 500 of Fig. 5a. More specifically, Fig. 5d illustrates an implementation of the timing-circuit forming a part of the Fig. 5a and accordingly represents a variant of the circuit as depicted in Fig. 5 a.
At least by virtue of the present features, the present subject matter confines the sounding of buzzer within the receiving vehicles and accordingly substantially minimizes the noise from reaching the outside environment, which is otherwise observed during the audible horn operation. Accordingly, the non-audible signal transmission in the form of IR signal triggers the intended buzzer at intended recipient vehicle only.
Embodiments of the present invention have been described in detail for purposes of clarity and understanding. However, it will be appreciated that certain changes and modifications may be practiced within the scope of the present invention. Thus, although the present invention is described with reference to specific embodiments and drawings thereof, the embodiments and drawings are merely illustrative, and not limiting of the present invention.

We Claim;
1. A system (200) for communicating a radio-signal for generating a horn, said system comprising:
an oscillator (204) for generating a low-power signal at a pre-determined frequency based on triggering by a user-operable switch (SI);
a semiconductor switching element based gate-driver circuit (206) for driving a power semiconductor-switch (208) based on the low-power signal and thereby switching ON the power semiconductor-switch (208); and
a transmitter (210) for transmitting a modulated radio-signal based on the switched ON state of the semiconductor-switch (208) and in accordance with said predetermined frequency to enable generation of a sound of a predetermined decibel (dB) level of an acoustic horn at a receiver end.
2. The system (200) as claimed in claim 1, wherein the oscillator (204) corresponds to at
least one of:
an astable, monostable or bistable multi-vibrator; a multi-vibrator IC defined by CD 4047 .
3. The system (200) as claimed in claim 1, wherein the switching elements in the gate
driver-circuit (206) comprises:
a push-pull configuration comprising transistors (Ql and (Q2);
a CMOS inverter configuration comprising MOSFETs (Q4 and Q2); and
4. The system (200) as claimed in claim 1, wherein the power switching-element (208) is defined by an NMoS based power MOSFET.
5. The system (200) as claimed in claim 1, wherein the transmitter is an IR transmitter (210) comprising a group of IR LEDs for emitting IR radiation upon energization.
6. A system (400) for wirelessly-receiving signal for generating a horn and controlling thereto, said system (400) comprising:

a receiver-circuit (404, 406) configured for receiving and demodulating a received radio-signal;
a voltage-reduction mechanism (R4, R5, R6, R7) for rendering a reduced power-supply;
a differential amplifier (408) for receiving the demodulated-signal from the receiver (406) and the reduced power supply to amplify a difference there-between;
a buzzer (414) for receiving the amplified signal from the differential amplifier (408) to generate a horn based audible-sound at a predetermined decibel (dB) level; and
a manually operable delay circuit (410) to delay an operation of the differential amplifier (408) by a predetermined-time to stop said generation of sound.
7. The system (400) as claimed in claim 6, wherein the receiver-circuit is defined by at-least
one of:
a voltage regulator IC (7805 IC) (404) for maintaining a constant supply-voltage;
a plurality of bypass-capacitors (C3 and C4) to filter AC-ripple within the supply voltage; and
an IR-receiver (406) defined by an assembly of Photo Detector, Gain Control, Band Pass Filter, Demodulator and a Pre-amplifier.
8. The system (400) as claimed in claim 7, wherein the IR receiver (406) is TSOP 1738 based integrated circuit.
9. The system (400) as claimed in claim 6, wherein the differential amplifier (408) is a comparator defined by:
a received signal at the non-inverting input; and a low-voltage power supply at the inverting-input.
10. The system (400) as claimed in claim 6, wherein the timer (410) is a TSOP 173 555
timer IC.