FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
MOBILE AC MONITOR FOR EVALUATING
AC SYSTEM PERFORMANCE


APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
an Indian company having its registered office at
S. K. Jaybhay and S. H. Kapoor both Indian national of TATA MOTORS LIMITED
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Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India

PREAMBLE TO THE DESCRIPTION
The following specification describes the invention.

Field Of Invention
Technical field
The mentioned invention refers to method & system for evaluating performance (health) of a mobile AC system. It is possible by capturing-
1. The temperatures of the air coming out from AC vents as well as ambient temperature, it will captured by putting thermocouples at vents.
2. The pressure of refrigerant on low side & high side in AC system- This will be communicated from pressure transducers attached with suction & discharge ports given in AC system.
From pressure & temperature data portable kit will help to vehicle owner (user of mobile AC unit or car owner) to judge the vehicle AC unit performance. Accordingly it will suggest remedy to user.
Background
Our society is not able to judge the AC system effectiveness in their vehicle. They are dependent on the workshop mechanic to check AC performance. Most of "AC SYSTEM" fitted automobiles have "main engine" driven compressor, it is directly related to fuel consumption of engine. Effective AC system will avoid excessive fuel consumption & non stop running of AC compressor. For detecting any failures or finding correct remedy for correcting AC performance needs different costlier equipments at once. To check AC system is a difficult task & its time consuming. Simple check of AC system needs pressure gauge, thermocouples, data recording machine & proper instrumentation on vehicle. After carrying out experiment data needs to be downloaded on computer & needs to be processed to conclude on it. It is time consuming job as well as not possible for car owner or common workshop mechanic.
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A need exits for a practical, programmable, user friendly & affordable portable system which will judge the mobile AC performance. A common man can use this portable system & will get feedback equivalent to thermal expert's feedback. Following parameters are required to check for concluding MOBILE AC SYSTEM working properly or not. Present invention is helpful to select proper remedy for respective fault.
1. Ambient temperature (DBT °C)
2. Relative humidity (RH %)
3. low side pressure (bar) & high side pressure (bar) of compressor
4. Vents temperature (Minimum two).
In general the HVAC System of an automobile air conditioning consists of a low pressure side (Evaporator, Heater), a high pressure side (Condenser, RD Bottle) with compressor & TXV as entity which separates these sides. The arrangement of the system components varies with respect to application & the segment of the vehicle. Most of vehicles are with main engine mounted compressor, condenser in front of radiator for getting benefit from ram air, dryer & reservoir bottle (RD Bottle) in engine compartment, TXV (expansion valve) mounted with evaporator coil & evaporator coil is preferably placed under the dash board of vehicle. For a dual HVAC system in a luxury sedan vehicle the second evaporator is placed at the rear for extra comfort, whereas in case of a mini van it is mounted at roof.
Objects of invention
User of automobile cars doesn't know much about AC system of vehicle, if any mobile AC performance complaint (for example: cooling not adequate) arrives from car user, to AC mechanic or vehicle mechanic, without knowing proper reason for poor performance of mobile AC system or without doing any root cause analysis or observation, the AC mechanic are recharging the AC system with refrigerant. This is wastage of time for customer (car or vehicle owner). Most of the time, above stated
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action will not resolve the complaint. With present invention user will judge the performance of AC system as well as he will get remedy for related fault from equipment. Due to present invention, for judging AC system performance thermal experts are not required. It will be very useful for a common man or user of mobile AC.
The prime object of this invention is to have handy device (portable kit) to confirm MOBILE AC SYSTEM functioning. It will be equipped with capability of measuring all related parameters & processing captured data in a short span of time (approx two minutes) after capturing data. This portable device will be with input & output screen, will help to car owner to check AC system of their vehicle is working properly or it needs any repair. It is providing the complete solution to mobile AC users, AC mechanics & AC test engineers.
Brief description of Invention
This device is portable, easy to handle & user friendly. It is equipped with following systems-
1) Two pressure transducers to measure pressure on suction (low side) & discharge (high side) of refrigerant circuit,
2) Four thermocouples to sense the temperature at vents,
3) Alphanumeric graphical display screen for displaying input data and processed data as per selected display mode.
4) Mode selection button to select display mode,
5) Power on/off button for equipment on off function,
6) Microprocessor for processing data & a central processing unit (CPU) that can execute software programs,
7) Memory to store the software as well as data captured,
8) Data processing software to process data & link the results with conclusions based on logic,
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9) Data transfer ports for attaching the equipment to computer.
Brief description of different drawing views
For more complete understanding of invention different figures are included. The figures are marked with numbers & same numbers are used in detailed description for easier understanding.
FIGURE: 1 - It shows perspective view of a portable "MOBILE AC MONITOR" (21) according to the present invention, it includes the measuring, transmitting & display unit.
FIGURE: 2 - Schematic diagram of display unit with different mode of display of
present invention.
FIGURE: 3 - Schematic diagram of data flow of present invention.
FIGURE: 4 - Logic diagram for present invention.
FIGURE: 5 - Measuring & transmitting part of present invention.
Detail description of the invention
Referring to Figures from 1 to 5 the numbers from 1 tp 17 are included for explaining present invention & these are reference numbers for detailed description present innovation, list of reference numbers is given below-
(1) Alphanumeric liquid crystal display
(2) Mode selection button
(3) Indication lamp
(4) Power on / off button
(5) Battery (power supply)
(6) Input signal port for pressure transducer (Two Nos)
(7) Input signal port for thermocouples (Four Nos)
(8) Thermocouple pin (Four Nos)
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(9) Thermocouple(Four Nos)
(10) Pressure transducer signal wire for low side pressure
(11) Pressure transducer for low side pressure
(12) Pressure transducer signal wire for high side pressure
(13) Pressure transducer for high side pressure
(14) Microprocessor
(15) Data recorder / encoder
(16) Memory
(17) Error signal (LED)
Referring to figure: 1; A portable mobile AC monitor consists of total 17 major types of main components. Main display unit (1) is capable of displaying the alphanumeric data, processed graphical data. The different modes of display can be selected by (2) mode selection button. The user can see the data as shown in figure: 2, basic parameters in mode-1, major parameter in mode- 3, conclusion & remedy in mode- 5, mode 2 & 4 will be useful for graphical result display. Indication lamp (3) is LED lamp will be green color & will indicate the equipment power on, Power on / off button (4) will used for on & off of equipment. Rechargeable battery (5) will be capable of keeping equipment in operation at least for four hours.
Logical sequence
For input signal from thermocouple (9), equipment is having (7) plug with (8) pin. Pressure transducers (11) & (13) will be connected through cables (10) & (12) to equipment. The data from thermocouple (9), pressure transducer (13) & (11) will be recorded in (15) data recorder/encoder & decoded signal is sent to microprocessor. Memory unit (16) & microprocessor (14) will process the data received from (15) data recorder/encoder, as per selection of mode (2) by mode selection button the microprocessor will send the processed data to display (1).
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During capturing the data the CPU (Microprocessor (14) + (15) Data recorder/encoder + (16) Memory), regardless of the physical form they take, is to execute a sequence of stored instructions called a program. The program is represented by a series of numbers that are kept in (16) memory. There are four steps that nearly all CPUs use in their operation: fetch, decode, execute, and write back. After the execution of the instruction and write back of the resulting data, the entire process repeats, with the next instruction cycle normally fetching the next-in-sequence instruction because of the incremented value in the program counter. If the completed instruction was a jump, the program counter will be modified to contain the address of the instruction that was jumped to, and program execution continues normally. After write back the as per mode selection data is displayed. Error signal will be given by LED (17) in case of equipment fault; Memory (16) is equipped with software programs for processing data captured for certain period, CPU will (Microprocessor (14) + (15) Data recorder/encoder + (16) Memory) compare the processed results with target values in system & give the conclusion. The system is equipped with remedy text with technical words which can be understood by common user.
Brief description about equipment application
(18, 19, 20 are numbers used for AC control knobs of mobile AC system)
1. Park the vehicle in shade with bonnet closed, apply parking brake,
2. Attach thermocouples (9) with vehicle AC vents,
3. Attach pressure transducers low pressure side (11) & high pressure side (12) to ports of vehicle AC system,
4. Connect thermocouples connectors (8) to "MOBILE AC MONITOR" (21) related inlet ports (7),
5. Connect cords from pressure transducers (10 & 12) to "MOBILE AC MONITOR" (21) related inlet ports (6),
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6. Close the vehicle doors; put the gear lever neutral,
7. Start engine & accelerate engine at 1200 RPM,
8. Switch on AC blower & keep it at maximum blower speed by (18),
9. Select maximum cool option (18),
10. Select chest mode by (20),
11. Start "MOBILE AC MONITOR" (21) by start button (4),
12. Run the engine for 10 minutes at constant speed of 1200RPM,
13.After 10 min. select mode-5 for RESULT by mode selection button, it will appear with any one of the following option analyzing data-OK - AC system is performing OK. Minor - screen will show check points. Major - Message will come to take vehicle to workshop.
Following are benefits from present invention
1. It is handy portable kit, simple & easy to understand for non technical person,
2. Car owner can get confidence about their own vehicle AC system performance as well as information about necessary remedies if required within 20 minutes time.
3. For repetitive work like testing of "MOBILE AC SYSTEM" for 100 vehicles (we can say first production batch or proto batch) it will be very useful & less time consuming for quick check up.
4. At automobile dealer end or repair center, MOBILE AC SYSTEM mechanic can check the system in very less time; will get proper guideline for repair if it is necessary.
5. Fault & its severity will be concluded; related corrective action will be displayed on screen, it will be equipped with audio output which will tell results in the form of voice also.
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The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.