Field of the Invention
The present invention relates to an alarm circuit assembly for indicating the unlock/disengaged condition of a fuel cap. More particularly, the present invention relates to a circuit that detects open ground connection occurring between a fuel cap and the rim of the fuel tank. The alarm circuit of the present invention replaces an electro¬mechanical switch with two conductive parts which establishes a circuit on ground pulse and which in turn acts as a switch.
Background of the Invention:
It is known than the fuels used in motor vehicles are very volatile in nature due to which their rate of evaporation is very high. Hence, in automobile industry, lot of care is taken to keep the fuel tank of a motor vehicle always closed.
Further study shows that fuel tank of a motor vehicle should be able to withstand the vapour pressure built by the fuel inside it without any leakage. However, the fuel contained inside the fuel tank is prone to evaporation. Therefore, it is utmost necessary to provide a fuel cap so as to maintain a high air tightness function with respect to fuel filler neck.
In addition, if the fuel cap is open there are possibilities of theft of the fuel contained in the fuel tank. Further, it may also possible that the fuel may expose to the dust contained in the environment and there is also likelihood of getting expose with explosive elements. Hence, it is very essential to keep the fuel tank closed by using a cap.
However, there are situations were people tend to forget to close the fuel tank using the fuel cap. Also, there have been situations, when the user tries to close the fuel tank cap however, the cap still remains partially open due to nonalignment or less application of force...etc.
In order to overcome stated problems, many attempts have been made to provide systems for automatically closing the fuel tank using latch mechanisms and various other mechanical means to close the fuel tank cap. However, the said mechanisms are either cumbersome or expensive. Further, there are various other disadvantages, wherein the

mechanical systems like latches are subjected to various wear and tears which can make the entire mechanism to fail.
Alternative arrangements were experimented such as using electrical connections to detect whether the fuel tank is closed or not, using conductivity. Accordingly, an electrical circuit is connected between the rim of the fuel tank and the fuel tank cap. The said circuit is powered by DC power source and the entire connections are linked with the ignition switch of the motor vehicle. It should be note that if the fuel tank cap is not closed properly the circuit will be open and in turn the motor vehicle cannot be started.
However, the major drawback in this system is that the circuit which uses the conductivity of the fuel tank cap and the fuel tank rim can experience spark in the fuel tank which can lead to destructions or catastrophe. Attempts were made to rectify the circuit by a switch. However, provision of switch leads to current loss and also experience wear and tear.
Therefore, there exist a need for providing an alarm circuit for indicating the unlock/disengaged condition of a fuel cap eliminating all the hazards listed above.
Objective of the Invention;
The main objective of the present invention is to provide an alarm circuit for indicating the unlock/disengaged condition of a fuel tank cap eliminating the above listed hazards by replacing an electro-mechanical switch with two conductive parts which establishes a circuit on ground pulse and which in turn acts as a switch.
Summary of the Invention:
Accordingly, the present invention relates to an alarm circuit assembly/device for indicating the unlock condition of a fuel cap, the said assembly/device comprising: a semiconductor device comprising first, second and third terminals; an alarm circuit being operationally coupled to the said first terminal of the semiconductor device and in turn coupled to a power supply; a fuel cap switch assembly comprising a fuel cap and a rim; wherein, the said fuel cap being operationally coupled to the said second terminal of the semiconductor device and the said rim of the fuel tank being grounded; the said fuel cap

switch assembly being configured to actuate the alarm circuit for indicating an open condition of the said fuel cap when the ground circuit is open.
Also, the present invention relates to an alarm circuit assembly for indicating the unlock/disengaged condition of a fuel cap, the said device comprising: an alarm circuit; a semiconductor device coupled to the said alarm circuit, a fuel tank assembly comprising a fuel cap and a fuel cap engaging means for closing the fuel tank; wherein, one end of the said fuel cap engaging means is grounded and the other end is engaged with the said fuel cap forming a closed loop circuit; the said fuel cap when disengaged with the said fuel cap engage-able means, breaks the closed loop circuit thereby triggering a signal to the semiconductor device which in turn activates the alarm circuit to generate an alarm for indicating the unlock/disengaged condition of a fuel cap.
The following paragraphs are provided in order to describe the best mode of working the invention and nothing in this section should be taken as a limitation of the claims.
Brief Description of Figures:
Further aspects and advantages of the present invention will be readily understood from the following detailed description with reference to the accompanying drawings. Reference numerals have been used to refer to identical or similar functionally similar elements. The figures together with a detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present invention wherein:
Figure 1 show a block diagram of an alarm circuit used in accordance with the present invention.
Figure 2 shows a schematic circuit diagram of one embodiment of an alarm circuit in accordance with the present invention.
Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been 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 embodiments of the present invention.

Detailed Description of the Present Invention:
While the invention is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the invention as defined by the appended claims.
Before describing in detail embodiments it may be observed that the novelty and inventive step that are in accordance with the present invention resides in the circuit, accordingly, the drawings are showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such setup or device. In other words, one or more elements in a system or apparatus proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus. The following paragraphs explain present invention with respect to an alarm circuit for indicating the unlock/disengaged condition of a fuel cap. The invention in respect of the same may be deduced accordingly.
Accordingly, the present invention relates to an alarm circuit assembly/device for indicating the unlock condition of a fuel cap, the said assembly/device comprising: a semiconductor device comprising first, second and third terminals; an alarm circuit being operationally coupled to the said first terminal of the semiconductor device and in turn coupled to a power supply; a fuel cap switch assembly comprising a fuel cap and a rim; wherein, the said fuel cap being operationally coupled to the said second terminal of the semiconductor device and the said rim of the fuel tank being grounded; the said fuel cap

switch assembly being configured to actuate the alarm circuit for indicating an open condition of the said fuel cap when the ground circuit is open.
In another aspect of the present invention, wherein the said semiconductor device is a transistor.
In yet another aspect of the present invention, wherein the said first, second and terminals are collector, base and emitter terminals respectively.
In still another aspect of the present invention, wherein the said first, second and terminals are gain, source and drain terminals respectively.
In a further aspect of the present invention, wherein the said alarm circuit comprises: at least one relay to regulate alarm; an alarm; and an optical diode.
In a furthermore aspect of the present invention, wherein the said fuel cap assembly is made up of electrically conductive materials.
In one more aspect of the present invention, wherein the said power source is a DC power source.
In another aspect, the present invention also relates to an alarm circuit assembly for indicating the unlock/disengaged condition of a fuel cap, the said device comprising: an alarm circuit; a semiconductor device coupled to the said alarm circuit, a fuel tank assembly comprising a fuel cap and a fuel cap engaging means for closing the fuel tank; wherein, one end of the said fuel cap engaging means is grounded and the other end is engaged with the said fuel cap forming a closed loop circuit; the said fuel cap when disengaged with the said fuel cap engage-able means, breaks the closed loop circuit thereby triggering a signal to the semiconductor device which in turn activates the alarm circuit to generate an alarm for indicating the unlock/disengaged condition of a fuel cap.

Detailed Description of the drawings:
The present invention relates to an alarm circuit for indicating the unlock/disengaged condition of a fuel cap. More particularly, the present invention relates to a circuit that detects open ground connection occurring between a fuel cap and the rim of the fuel cap.
The alarm circuit of the present invention replaces an electro-mechanical switch with two conductive parts which establishes a circuit on ground pulse and which in turn acts as a switch.
Fig. 1 represents the basic block diagram of an alarm circuit. Accordingly, said block diagram provides a DC Power source, a Control Circuit, an Alarm, regulator and relay. Control circuit is connected to the regulator for regulating DC voltage. Further, control circuit is connected to the Alarm and the relay.
Fig. 2 represents the circuit comprising: an arrangement of DC source, fuel tank cap, fuel cap engage-able means (fuel tank rim) and alarm means with various resistors, diode, transistor and relay switch. The DC voltage source is connected to the terminals 1,2,3,4 wherein the said terminals are further connected with a diode (Dl), relay, alarm unit comprising LED and Buzzer. Further, the said terminals 1-4 are connected to the collector terminal 5 of the transistor and the emitter terminal 6 of the transistor is grounded. Further, the base terminal of the transistor is connected to a terminal 8, whereby one end of resistor R2, R3, R4 and diode D2 are joined. The other end of the R2 is connected to base terminal 7 of the transistor. Other end of Resistor R3 is connected to the terminal 1 which inturn is connected to diode Dl. Second end of the diode D2 is connected to the Fuel tank cap. Further, another end of the resistor R4 is splitted into two ends in such a way that one end is grounded at terminal 9 and the other end is connected to fuel cap engage-able means (can also be termed as fuel tank rim).
Wherein the transistor can be selected from the group comprising but not limited to bipolar junction transistors, field effect transistors, junction field effect transistors, metal-oxide-semiconductor field effect transistor.

While one embodiment of this invention with several options has been presented above, many changes can be made without departing from the spirit and scope of the invention. The various insights embodied in this invention enable the production of alarm circuit for alarm circuit assembly/device for indicating the unlock condition of a fuel cap at significantly reduced costs, while still attaining the desired result in efficient manner. The scope of this invention should be determined by the appended claims and their legal equivalents, rather than by the explanations or illustrations here presented.
Working of the Invention;
Case 1: Open condition of Fuel Tank Cap
During the open condition the fuel tank cap is disengaged with the fuel tank rim due to which the ground connection is open. This is due to the reason that the fuel tank cap and the fuel tank rim forms part of the circuit. Due to non conductivity, the ground connection of the circuit becomes open and the circuit connected to the collector terminal gets activated and routes the DC supply to the alarm unit i.e. LED and/or buzzer.
Case 2: Close condition of Fuel Tank Cap:
In case of close condition, the fuel tank rim is engaged with the fuel tank cap making the ground connection closed. In this condition, the base and emitter terminal of the transistor are activated and the entire current will pass on to the ground and thereby disconnecting the alarm circuit.
Advantage;
1) The circuit of present invention is very simple.
2) The present circuit avoids occurrences/formation of any sparks at the conjunction of two conductive materials.
3) The present circuit is inexpensive.
4) The application of the alarm circuit of the present application is universal and can be used in many home appliances such as such as Refrigerators, microwave ovens etc

The advantages of the disclosed invention are thus attained in an economical, practical, and facile manner. While preferred aspects and example configurations have been shown and described, it is to be understood that various further modifications and additional configurations will be apparent to those skilled in the art. It is intended that the specific embodiments and configurations herein disclosed are illustrative of the preferred nature of the invention, and should not be interpreted as limitations on the scope of the invention.

We Claim:
1. An alarm circuit assembly for indicating the unlock condition of a fuel cap, the
said assembly comprising:
a semiconductor device comprising first, second and third terminals;
an alarm circuit being operationally coupled to the said first terminal of the semiconductor device and in turn coupled to a power supply;
a fuel cap switch assembly comprising a fuel cap and a rim;
wherein,
the said fuel cap being operationally coupled to the said second terminal of the semiconductor device and the said rim of the fuel tank being grounded;
the said fuel cap switch assembly being configured to actuate the alarm circuit for indicating an open condition of the said fuel cap when the ground circuit is open.
2. The alarm circuit assembly as claimed in claim 1, wherein the said semiconductor device is a transistor.
3. The alarm circuit assembly as claimed in claim 1, wherein the said first, second and terminals are collector, base and emitter terminals respectively.
4. The alarm circuit assembly as claimed in claim 1, wherein the said first, second and terminals are gain, source and drain terminals respectively.
5. The alarm circuit assembly as claimed in claim 1, wherein the said alarm circuit comprises:
at least one relay to regulate alarm; a buzzer alarm; and an optical diode.
6. The alarm circuit assembly as claimed in claim 1, wherein the said fuel cap
assembly is made up of electrically conductive materials.
7. An alarm circuit assembly for indicating the unlock/disengaged condition of a
fuel cap, the said device comprising:
an alarm circuit;
a semiconductor device coupled to the said alarm circuit,
a fuel tank assembly comprising a fuel cap and a fuel cap engaging means for
closing the fuel tank;
wherein,
one end of the said fuel cap engaging means is grounded and the other end is engaged with the said fuel cap forming a closed loop circuit;
the said fuel cap when disengaged with the said fuel cap engage-able means, breaks the closed loop circuit thereby triggering a signal to the semiconductor device which in turn activates the alarm circuit to generate an alarm for indicating the unlock/disengaged condition of a fuel cap.
8. The alarm circuit assembly as claimed in claim 7, wherein the said semiconductor
device is a transistor.
9. The alarm circuit assembly as claimed in claim 7, wherein the said alarm circuit
comprises:
at least one relay to regulate alarm; a buzzer alarm; and an optical diode.
10. The alarm circuit assembly as claimed in claim 1, wherein the said fuel cap and
the said fuel cap engaging means are made up of electrically conductive materials.