DESC:FIELD OF INVENTION
The present invention relates generally to level sensing of liquid. More particularly, the present invention relates to Hall Effect level sensing device with single magnet for sensing liquid level present in a container. Advantageously, the present invention eliminates isolation layer formation between the sensing device and contact material due to adulterated fluid or chemical reaction between fluid and the sensing device.

BACKGROUND OF INVENTION
A level sensor is generally used to sense the level of fluid in a tank. There are two kinds of level sensors namely contact type and non-contact type. In contact type sensors, wire wound, Thick Film Resistor (TFR) technologies are used and in non-contact type sensors, reed switch, capacitance, ultrasound etc. technologies are used.

Contact type sensors are widely used in small segment automobiles like two wheeler, four wheeler fuel level sensing, Genset fluid level sensing, etc. Signal will be generated when spring contact applies pressure on sensing system in case of the contact type sensor. Contact type sensors are widely used where fuel tanks are non-linear or complicated profiles. Non-contact type sensors are widely used in heavy vehicle application, Genset etc. Signal from the sensor with reference to the level is generally fed to a display unit or Electronic Control Unit (ECU) to process further to display the level or to control other applications. Some of the non-contact type level sensors are not suitable for some types of fluid like conducting mediums, dark mediums, high viscous mediums etc. . Non-contact type sensors are widely used where fuel tanks are linear like square, rectangle or circular tanks.
The constraints/issues faces in the contact type level sensors are contact pressure variation between spring contact and sensing system leads to abnormal signal or no signal from the sensor. The contact pressure on the sensing system may increase due to assembly process or sloshing effect during operation, which will lead to wear out of the sensing system. The spring contact gets damage due to sloshing effect of fluid inside the tank since spring contact is flimsy part with spring back property. Isolation layer is formed between the sensing system and contact material due to adulterated fluid or chemical reaction between the fluid and sensing system.

WO1988001046 discloses a liquid level sensing system for use with a closed container having a varying level of liquid comprising float means within the container movable in response to variations in the level of liquid within the container, rotatably magnetic field means within the container connected to the float means so as to be at least partially rotated upon movement of the float means, stationary magnetic field sensing means outside the container for detecting variations in the position of the magnetic field caused by the partial rotation of the magnetic field of the rotatable magnetic means.

3990/DEL/2014 discloses a non-contact type apparatus for sensing the level of fluid within a tank that comprises of a bracket snap fitted to the tank, and a plastic housing provided beneath the bracket to accommodate a printed circuit board assembly. The printed circuit board assembly further comprises of a printed circuit board, a Hall integrated chip, and wired cables electrically connected to the Hall integrated chip. The subject matter further discloses a clamp mounted to hold the plastic housing and a U-shaped arm attached to the clamp in two in-built grooves to receive the two ends of the U-shaped arm.

Accordingly, there exists a need for Hall Effect level sensing device with single magnet, which overcomes the constraints/issues faced in the contact type level sensor and uses of advantages in non-contact type level sensor. Non-contact sensing solution for the non-linear tanks are required to overcome the above issues and Hall Effect based sensor is the solution.

OBJECTS OF INVENTION
One or more of the problems of the conventional prior art may be overcome by various embodiments of the present invention.

Accordingly, it is the primary object of the present invention to provide Hall Effect level sensing device with single magnet with Hall Effect sensing element which is programmable type or pre-programmed type provided for sensing liquid level present in a container.

It is another object of the present invention to provide Hall Effect level sensing device with single magnet, which overcomes the constraints/issues faced in the contact type level sensor and uses of advantages in non-contact type level sensor.

It is another object of the present invention to provide Hall Effect level sensing device with single magnet, which eliminates isolation layer formation between the sensing device and contact material due to adulterated fluid or chemical reaction between fluid and the sensing device.

SUMMARY OF INVENTION
Thus according to the basic aspect of the present invention there is provided a Hall Effect level sensing device, comprising:
flange with housing, said housing houses sensing element and Printed Circuit Board (PCB);
at least one magnet;
lever arm; and
float,
wherein the sensing element and the PCB are isolated from direct contact with fluid inside the tank,
wherein one end of the lever arm is connected with the float and pivot point of the lever arm is attached to the flange with housing through a magnet holder,
wherein the magnet is housed in one side of the magnet holder facing the housing of the
Hall Effect level sensing device, and
wherein other side of the magnet holder is provided with one or more protrusions to hold the lever arm such that said lever arm moves parallel or perpendicular to the sensing element.

It is another aspect of the present invention, wherein the PCB is fixed within the housing and covered with sealant to isolate from direct fluid contact.

It is another aspect of the present invention, wherein one end of the magnet holder is provided with a slot through which the pivot point of the lever arm is attached to the flange with housing.

It is another aspect of the present invention, wherein the pivot point of the lever arm swings radially while the float moves up or down based on the level of fluid inside a container.

It is another aspect of the present invention, wherein movement of the magnet located in the magnet holder with reference to the position of the sensing element creates change in magnetic flux on the sensing element.

It is another aspect of the present invention, wherein the output from the sensing element is fed to a connecting terminal through the protrusion in the flange for interfacing with cluster/ECU or to control other applications.

It is another aspect of the present invention, wherein the output from the sensing element is fed as input to an additional electronic circuitry for converting said output from the sensing element into forms of outputs as per requirement.

It is another aspect of the present invention, wherein the sensing element is a Hall Effect sensing element that is programmable or pre-programmed .

BRIEF DESCRIPTION OF THE DRAWINGS:
Figure 1: illustrates Hall Effect level sensing device with single magnet according to the present invention.
Figure 2: illustrates the enlarged view of a portion of Figure 1 according to the present invention.
Figures 3a and 3b: illustrates various positions of moveable arm with respect to the sensing element according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING FIGURES
The present invention is thus directed to Hall Effect level sensing device with single magnet for sensing liquid level present in a container. Advantageously, the present invention eliminates isolation layer formation between the sensing device and contact material due to adulterated fluid or chemical reaction between fluid and the sensing device.

Referring to Figures 1 to 3b, the Hall Effect level sensing device comprises of flange [8] with housing [4], said housing [4] houses Hall Effect sensing element [1] and Printed Circuit Board (PCB) [3]; at least one magnet [2]; lever arm [5]; and float [6]. The sensing element [1] and the PCB [3] are isolated from direct contact with the fluid inside the tank. The PCB [3] is rigidly fixed within the housing [4] and covered with sealant to isolate from the direct fluid contact, said sealant includes but not limited to plastic or epoxy solutions. One end of the lever arm [5] is connected with the float [6] and pivot point [9] of the lever arm [5] is attached to the flange [8] with housing [4] through a magnet holder [2a]. The sensing element [1] is located in pre-defined position in the PCB [3] within the housing [4]. The magnet [2] is housed in one side of the magnet holder [2a] as shown in Figure 2 facing the housing [4] of the Hall Effect level sensing device. One end of the holder is provided with a slot through which the pivot point [9] of the lever arm [5] is attached to the flange [8] with housing [4]. Other side of the magnet holder [2a] is provided with one or more protrusions to hold the lever arm [5] as shown in Figure 2 such that said lever arm [5] moves parallel to the sensing element [1].

The pivot point [9] of the lever arm [5] swings radially while the float [6] moves up or down based on the level of fluid inside a container as shown in Figures 3a and 3b. The swinging action of the moveable arm [5] provides variation in air gap between the sensing element [1] and magnet [2] located in the lever arm [5]. Movement of the magnet [2] located in the magnet holder [2a] with reference to the position of the sensing element [1] creates change in magnetic flux on the sensing element [1]. The sensing element [1] converts the change in the magnetic flux on the sensing element [1] into a linear voltage signal. The output from the sensing element [1] is fed to a connecting terminal [7] through the protrusion in the flange [8] as shown in Figures 1 and 2 for interfacing with cluster/ECU or to control other applications.

Optionally, the output from the sensing element [1] is fed as input to an additional electronic circuitry for converting said output from the sensing element [1] into forms of outputs as per requirement such as voltage, current, resistance, CAN signals, RS232 signals, RS485 signals etc. The sensing element [1] is a Hall Effect sensing element. It should be noted that the dimensions of the housing [4] of the Hall Effect level sensing device and specification of the PCB [3] depends on vehicle application.

Since the sensing element [1] and the PCB [3] are isolated from direct contact with the fluid inside the tank, the same eliminates formation of isolation layer between the sensing device and contact material.

The advantages of the present invention are as follows:
• Suitable to sense the level of fluid in small, medium and complex profile tanks.
• Suitable to sense the level of any type of fluids such as conducting mediums, dark mediums, high viscous mediums etc.

,CLAIMS:WE CLAIM:
1. A Hall Effect level sensing device, comprising:
flange [8] with housing [4], said housing [4] houses sensing element [1] and Printed Circuit Board (PCB) [3];
at least one magnet [2];
lever arm [5]; and
float [6],
wherein the sensing element [1] and the PCB [3] are isolated from direct contact with fluid inside the tank,
wherein one end of the lever arm [5] is connected with the float [6] and pivot point of the lever arm [5] is attached to the flange [8] with housing [4] through a magnet holder [2a],
wherein the magnet [2] is housed in one side of the magnet holder [2a] facing the housing [4] of the Hall Effect level sensing device, and
wherein other side of the magnet holder [2a] is provided with one or more protrusions to hold the lever arm [5] such that said lever arm [5] moves parallel to the sensing element [1].

2. The Hall Effect level sensing device as claimed in claim 1, wherein the PCB [3] is fixed within the housing [4] and covered with sealant to isolate from direct fluid contact.

3. The Hall Effect level sensing device as claimed in claim 1, wherein one end of the magnet holder [2a] is provided with a slot through which the pivot point [9] of the lever arm [5] is attached to the flange [8] with housing [4].

4. The Hall Effect level sensing device as claimed in claim 3, wherein the pivot point [9] of the lever arm [5] swings radially while the float [6] moves up or down based on the level of fluid inside a container.

5. The Hall Effect level sensing device as claimed in claim 1, wherein movement of the magnet [2] located in the magnet holder [2a] with reference to the position of the sensing element [1] creates change in magnetic flux on the sensing element [1].

6. The Hall Effect level sensing device as claimed in claim 5, wherein the output from the sensing element [1] is fed to a connecting terminal [7] through the protrusion in the flange [8] for interfacing with cluster/ECU or to control other applications.

7. The Hall Effect level sensing device as claimed in claim 5, wherein the output from the sensing element [1] is fed as input to an additional electronic circuitry for converting said output from the sensing element [1] into forms of outputs as per requirement.

8. The Hall Effect level sensing device as claimed in claim 1, wherein the sensing element [1] is a Hall Effect sensing element.