The present disclosure relates to a control unit for a vehicle and in particular, relates to an
electrical HVAC control panel unit.
10 BACKGROUND
With the advancement of technology in the realm of automobiles, several control units,
such as mechanical control panel and, are employed for controlling Heating, Ventilation, and
Air Conditioning (HVAC) control unit of an automobile. The mechanical control panel may
15 include, but are not limited to, sliders, knobs, hi-con cable and latch switches.
Generally, an user of the automobile may use a control unit for operating and controlling
systems, such as Heating, Ventilation, and Air Conditioning (HVAC) unit. The user will provide
the input to manual hvac control unit for operating the functions like as AC signal on/off, rear
defogger, air intake direction, air distribution directions, air temperature, air flowing speed
20 control etc. via latch switches, knob operations with hi-con cable, contact make break switch
combination in manual operated control unit.
HVAC systems are designed to make use of certain standard types of motor controllers for
operating the valves, dampers, flaps, and other movable devices in the system. One such method
to achieve this is by using the Wheatstone bridge controller wherein resistance in control arms of
25 the bridge is varied, as with a solenoid actuator, and the motor is connected to the wiper arm of a
potentiometer in opposite arms of the bridge. The motor moves until the bridge is rebalanced.
When the controllers are hardwired to the control unit, the complexity of stringing wires
between the controllers and the control units limits the number of controllers which may be used
in any HVAC system. Such controller fails to control individual functions and a control unit
30 which is visible and operable by the user cannot control the multiple functionalities of the
HVAC. It is thus required to introduce circuitry and driver unit controlled elements that have the
capacity to control, not only the primary and secondary features of the HVAC. The problem
remains as how to interface each driver unit without complex hardwiring. A further problem
3
remains, especially in retrofitting existing HVAC installations for computer control, to utilize
the existing driver units.
Accordingly, it is an object of the present invention to provide an improved driver unit
which is adapted to interface existing equipment with a manually control unit which may be
5 connected to the driver unit as well as other electronic equipment in a circuitry arrangement by a
common signal link.
To our best knowledge this demand has remained unsatisfied in the automobile industry.
Therefore, it is an object to create a circuit arrangement and a method suitable for controlling the
driver unit thus affecting the HVAC unit of the automobile in a simple and reliable way, at low
10 cost.
The present invention relates to circuit arrangement of driver units and switches which are
especially adapted for use in heating, ventilating and air conditioning (HVAC) unit, utilizing a
circuitry arrangement and pre-defined logics which transmits output signals to controllers of the
HVAC system.
15
For instance, when the user requires to change the temperature of air, mechanical
arrangements included a knob for rotation in anti-clockwise and clockwise direction is provided.
The knob rotation enables the connected hi-con cable change the flap positions in HVAC. This
hi-con cable concept is implemented for the air distribution, air temperature and for air intake
20 functionalities. Further in, to enable and disable the Air Conditioning unit, fresh/recirculation,
defogger, demister etc. functions, the user pushes the latch switch and correspondingly a signal
is generated to the driver unit. The driver then generates a signal to the master Electronic
controller unit (ECU) in the automobile. The master ECU will take action after receiving the
confirmed signal from the driver unit.
25
SUMMARY
In an embodiment of the present disclosure, an arrangement for controlling HVAC unit of
an automobile is disclosed. The arrangement includes a control unit adapted to be operated by a
30 user, wherein the control unit is configured to transmit reference signal (Rs). A driver unit
connected with a power supply and adapted to operate the HVAC unit, wherein the driver unit is
configured to receive reference signal (Rs). An actuating motor adapted to change position of at
least one flap, wherein the actuating motor transmits position feedback signal (Ps) to the driver
4
unit. The driver unit is configured to transmit an operation signal to the actuating motor based on
determining difference between the reference signal (Rs) and position feedback signal (Ps).
In an aspect of the invention, the control unit is connected with a potentiometer; wherein
the potentiometer is configured for generating a difference in voltage parameter; and generating
5 the reference signal (Rs) based on the difference in voltage parameter when the user operates the
control unit.
In an aspect of the invention, the driver unit sends the operation signal: to rotate actuating
motor counter clockwise (410) wherein the reference signal (Rs) is greater than the position
feedback signal (Ps); to rotate actuating motor clockwise (412) wherein the reference signal (Rs)
10 is smaller than the position feedback signal (Ps);
In another aspect of the invention wherein the driver unit is further connected with a
hysteresis controller; wherein the reference signal (Rs) is equal to the position feedback signal
(Ps), the hysteresis controller is configured to prevent the driver unit to transmit the operation
signal to the actuating motor.
15 In a preferred aspect of the invention, an arrangement for controlling HVAC unit of an
automobile includes a control unit adapted to be operated by a user, wherein the control unit is
connected with a tactile switch configured to generate a clock signal; a flip-flop driver unit
adapted to receiving and determining the clock signal, wherein the flip-flop driver unit is
configured to generating an output signal based on the clock signal; a terminal device connected
20 with the flip-flop driver unit and with a power supply, configured to receiving the output signal,
wherein the terminal device transmits a signal to a LED and a master electronic circuit unit
(ECU) based on the output signal.
In an aspect of the invention, the clock signal is a high pulse signal generated by the tact
switch in an enabled state; wherein the high pulse signal is transmitted to the flip-flop driver unit
25 for generating the output signal for activating the terminal device; wherein the terminal device
transmits the signal for activation of LED and master ECU.
In an aspect of the invention, the clock signal is a low pulse signal generated by the tact
switch in a disabled state; wherein the low pulse signal is transmitted to the flip-flop driver unit
for generating the output signal for deactivating the terminal device; wherein the terminal device
30 transmits the signal for deactivation of LED and master ECU.
In another preferred aspect of the invention, an arrangement for controlling HVAC unit of
an automobile includes, a control unit adapted to be operated by a user, wherein the control unit
is connected with a latch switch configured for generating a reference signal; a flip-flop driver
5
connected with the latch switch for receiving the reference signal, wherein the flip flop driver is
configured for generating an operating signal; a blower unit in connection with the flip-flop
driver, adapted to receive the operating signal.
In an aspect of the invention, the reference signal is an enable signal, wherein the flip-flop
5 driver generates the operating signal for activating the blower unit; further in a common terminal
in connection with the blower unit, wherein the common terminal is configured to close the
circuit for activation of an air conditioner unit.
In an aspect of the invention, the reference signal is a disable signal, wherein the flip-flop
driver generates the operating signal for deactivating the blower unit; further in a common
10 terminal in connection with the blower unit, wherein the common terminal is configured to open
the circuit for deactivation of an air conditioner unit when the blower unit is deactivated.
To further clarify advantages and features of the present invention, a more particular
description of the 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
15 typical embodiments of the invention and are therefore not to be considered limiting of its scope.
The invention will be described and explained with additional specificity and detail with the
accompanying drawings.
20 BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become
better understood when the following detailed description is read with reference to the
accompanying drawings in which like characters represent like parts throughout the drawings,
25 wherein:
Figure 1 illustrates a perspective view of a control unit for a vehicle, according to an
embodiment of the present subject matter;
30 Figure 2a illustrates a perspective view of a Flap of a HVAC unit in a closed state,
according to an embodiment of the present subject matter;
6
Figure 2b illustrates a perspective view of a Flap of a HVAC unit in an open state,
according to an embodiment of the present subject matter;
Figure 2c illustrates a perspective view of an actuating motor with position sensor of a
5 HVAC unit, according to an embodiment of the present subject matter;
Figure 3a illustrates a schematic view of interfacing of a potentiometer, an actuating
motor, and peripheral components for the control unit, according to an embodiment of the
present subject matter;
10
Figure 3b illustrates a schematic view of interfacing of a switch, a flip-flop driver unit, and
other peripheral components for the control unit, according to an embodiment of the present
subject matter;
15 Figure 3c illustrates a schematic view of interfacing of a switch, a flip-flop driver unit, and
other peripheral components for the control unit, according to an embodiment of the present
subject matter;
Figure 4 illustrates a block diagram view for interfacing of a potentiometer, an actuating
motor, and other peripheral components operated by the control unit as referenced in Figure 3a.
20
Further, skilled artisans will appreciate that elements in the drawings are illustrated for
simplicity and may not have necessarily been drawn to scale. For example, the flow charts
illustrate the method in terms of the most prominent steps involved to help to improve
understanding of aspects of the present invention. Furthermore, in terms of the construction of
25 the device, one or more components of the device 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 benefit of the
description herein.
30
DETAILED DESCRIPTION OF FIGURES
For the purpose of promoting an understanding of the principles of the invention, reference
will now be made to the embodiment illustrated in the drawings and specific language will be
7
used to describe the same. It will nevertheless be understood that no limitation of the scope of
the invention is thereby intended, such alterations and further modifications in the illustrated
system, and such further applications of the principles of the invention as illustrated therein
being contemplated as would normally occur to one skilled in the art to which the invention
5 relates. Unless otherwise defined, all technical and scientific terms used herein have the same
meaning as commonly understood by one of ordinary skilled in the art to which this invention
belongs. The system, methods, and examples provided herein are illustrative only and not
intended to be limiting.
10 Embodiments of the present invention will be described below in detail with reference to
the accompanying drawings.
For the purpose of promoting an understanding of the principles of the invention, reference
will now be made to the embodiment illustrated in the drawings and specific language will be
15 used to describe the same. It will nevertheless be understood that no limitation of the scope of
the invention is thereby intended, such alterations and further modifications in the illustrated
system, and such further applications of the principles of the invention as illustrated therein
being contemplated as would normally occur to one skilled in the art to which the invention
relates.
20
It will be understood by those skilled in the art that the foregoing general description and
the following detailed description are explanatory of the invention and are not intended to be
restrictive thereof.
25 Reference throughout this specification to “an aspect”, “another aspect” 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,
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.
30
The terms "comprises", "comprising", or any other variations thereof, are intended to cover
a nonexclusive 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
8
process or method. Similarly, one or more devices or subsystems or elements or structures or
components proceeded by "comprises... a" does not, without more constraints, preclude the
existence of other devices or other sub-systems or other elements or other structures or other
components or additional devices or additional sub-systems or additional elements or additional
5 structures or additional components.
Unless otherwise defined, all technical and scientific terms used herein have the same
meaning as commonly understood by one of ordinary skill in the art to which this invention
belongs. The system, methods, and examples provided herein are illustrative only and not
10 intended to be limiting.
It should be understood at the outset that although illustrative implementations of the
embodiments of the present disclosure are illustrated below, the present invention may be
implemented using any number of techniques, whether currently known or in existence. The
15 present disclosure should in no way be limited to the illustrative implementations, drawings, and
techniques illustrated below, including the exemplary design and implementation illustrated and
described herein, but may be modified within the scope of the appended claims along with their
full scope of equivalents.
20 The term “some” as used herein is defined as “none, or one, or more than one, or all.”
Accordingly, the terms “none,” “one,” “more than one,” “more than one, but not all” or “all”
would all fall under the definition of “some.” The term “some embodiments” may refer to no
embodiments or to one embodiment or to several embodiments or to all embodiments.
Accordingly, the term “some embodiments” is defined as meaning “no embodiment, or one
25 embodiment, or more than one embodiment, or all embodiments.”
The terminology and structure employed herein is for describing, teaching, and
illuminating some embodiments and their specific features and elements and does not limit,
restrict or reduce the spirit and scope of the claims or their equivalents.
30
More specifically, any terms used herein such as but not limited to “includes,”
“comprises,” “has,” “consists,” and grammatical variants thereof do NOT specify an exact
limitation or restriction and certainly do NOT exclude the possible addition of one or more
9
features or elements, unless otherwise stated, and furthermore must NOT be taken to exclude the
possible removal of one or more of the listed features and elements, unless otherwise stated with
the limiting language “MUST comprise” or “NEEDS TO include.”
5 Whether or not a certain feature or element was limited to being used only once, either
way it may still be referred to as “one or more features” or “one or more elements” or “at least
one feature” or “at least one element.” Furthermore, the use of the terms “one or more” or “at
least one” feature or element do NOT preclude there being none of that feature or element,
unless otherwise specified by limiting language such as “there NEEDS to be one or more . . .” or
10 “one or more element is REQUIRED.”
Unless otherwise defined, all terms, and especially any technical and/or scientific terms,
used herein may be taken to have the same meaning as commonly understood by one having an
ordinary skill in the art.
15
Reference is made herein to some “embodiments.” It should be understood that an
embodiment is an example of a possible implementation of any features and/or elements
presented in the attached claims. Some embodiments have been described for the purpose of
illuminating one or more of the potential ways in which the specific features and/or elements of
20 the attached claims fulfil the requirements of uniqueness, utility and non-obviousness.
Use of the phrases and/or terms such as but not limited to “a first embodiment,” “a further
embodiment,” “an alternate embodiment,” “one embodiment,” “an embodiment,” “multiple
embodiments,” “some embodiments,” “other embodiments,” “further embodiment”,
25 “furthermore embodiment”, “additional embodiment” or variants thereof do NOT necessarily
refer to the same embodiments. Unless otherwise specified, one or more particular features
and/or elements described in connection with one or more embodiments may be found in one
embodiment, or may be found in more than one embodiment, or may be found in all
embodiments, or may be found in no embodiments. Although one or more features and/or
30 elements may be described herein in the context of only a single embodiment, or alternatively in
the context of more than one embodiment, or further alternatively in the context of all
embodiments, the features and/or elements may instead be provided separately or in any
appropriate combination or not at all. Conversely, any features and/or elements described in the
10
context of separate embodiments may alternatively be realized as existing together in the context
of a single embodiment.
Embodiments of the present invention will be described below in detail with reference to
5 the accompanying drawings.
The present disclosure relates to electrical hvac control unit for controlling the hvac
function, and rest signals status sends to master ECU unit employed in a vehicle. The electrical
hvac control unit employed in vehicle with other control units to get functions status to further
10 process. The application / concept may include, but are not limited to a Heating, Ventilation, and
Air Conditioning (HVAC) only. The present disclosure offers the HVAC Unit functions
controlling with electrical system for the control unit which provides to control all include
functions (Air speed, Air Distribution, Air Intake direction, controlling of AC signal Rear
Demister) to a user, based on an input received from the user on the control unit. There are
15 normal concept-based application included but that are not limited, with using same concept, can
be add new features.
The present disclosure relates to electrical HVAC control system for a control unit
employed in the automobile. The control system unit may be in communication with the HVAC
20 unit and the automobile’s master electronic control unit (ECU). The control unit may be
employed in various applications of the automobile. The applications may include, but are not
limited to, a Heating, Ventilation, and Air Conditioning (HVAC). In an example, the user may
provide the input to the control unit though movement in attached knobs, or operate the key
switch, on this input sensing by control unit, on the action HVAC Control unit, it will operate an
25 actuating motor till the targeted function is not achieved. On the action of key switch for Air
Conditioner (AC), fresh/recirculation of air, rear demister functions, control unit will sense the
input, and correspondingly control unit provide the signal for creating an output via Master
ECU.
30 Figure 1 illustrates a perspective view of a control unit 100 for an automobile, according
to an embodiment of the present subject matter. The control unit 100 may be interchangeably
referred to as the user interface 100. The control unit 100 displays a plurality of rotating knobs
and a plurality of latching switches. A user of the automobile readily accesses the plurality of
11
rotating knobs and a plurality of latching switches thus operating the control unit 100 for
providing signal to the HVAC unit thus achieving a functionality. The control unit 100 is
connected with a circuit arrangement and other hardware elements in accordance with the
invention.
5
Figure 2a & Figure 2b illustrate a perspective view of HVAC unit 200 for the automobile,
according to an embodiment of present subject matter. In an embodiment, the HVAC unit 200
contain a flap 201 and 202 for bending or controlling the air flow. Figure 2a is representative of
the flap 201 in closed position. Figure 2b is representative of the flap 202 in open position.
10
Figure 2c illustrate a perspective view of an actuating motor 203 interfaced with the flap
201. The flaps 201, 202 are operated by the actuating motor providing signal for each function
like mode/air distribution, temperature/air mixing, and fresh/recirculation. In an embodiment, air
distribution and air mixing functions are achieved by the actuating motor 203 and the flaps
15 201/202, the actuating motor 203 provides the input supply via an input lead 204. The input lead
204 contains the actuating motor 203 input and position sensor signals directly interfaced with
the HVAC Control Unit.
The HVAC Unit 200 may include, but is not limited to, the flaps 201, 202, gear shaft, the
20 actuating motor 203, a position sensor, and the input/output leads 204. The HVAC unit 200 is
adapted to set the position of flaps 201, 202, in the open or closed state based on the user
operating the control unit 100. In an example, if the user set the requirement changes in
temperature or air distribution direction via the control unit 100, the control unit 100 is
connected with the input leads 204, the control unit 100 will provide signals to the actuating
25 motor 203 to come in operating condition. After receiving signal, the actuating motor 203 will
start to move in counter clockwise or clockwise and once the target position is achieved by the
actuating motor 203, the control unit 100 will stop the actuating motor 203 instantly.
The actuating motor 203 and the flap 201,202 will rotate and stop on same time due to
mechanical arrangements. According to the Flap 202 position, air flow will change the flowing
30 directions between ducting or can change ratio of hot air and cool air to make user friendly air
temperature. The Flap 202 will remain in the same position after supplying OFF to ON, or till
the new requirement is not provided by the user by rotating the knobs on the control unit 100. In
an embodiment, during a power supply 300, the flap 202 can change the position based on the
12
user input. On the other hand, during the absence of power supply, the flap 202 will stay remain
at same position which is provided by the user before power supply absence.
Figure 3a and Figure 4 illustrates schematic view of the actuating motor 203 interfacing
5 with the control unit 100, according to an embodiment of the present subject matter. The
actuating motor 203 may be in communication with the control unit 100 to maintain the flap 201
202 position. In the Figure 3a following components are illustrated: the power supply 300, a
resister network/Potentiometer 301, a Hysteresis controller 302, the driver unit 303, a motor
control leads 305, and a position feedback signal 304 (Ps) from the actuating motor 203. The
10 Potentiometer 301 may be configured to transmit signals as reference voltage signal to the driver
unit 303, based on the reference voltage signal generated/received when the user operates the
control unit 100 via rotating the knob. The power supply 300 section may be provided with a
protection and filtering circuit to protect it from the incoming surge and transients, its connected
as the power supply 300 with filter.
15 The driver unit 303 may be embodied as an Integrated Circuit, without departing from the
scope of the present disclosure. The driver unit 303 may be configured to receive voltages from
the power supply 300, more specifically, when the power supply section 300 is energised, it
sends the output to the driver unit 303. In an embodiment, the driver unit 303 may be configured
to receive signals from the battery and an ignition.
20
In an aspect of the invention, referring to Figure 4, the driver unit 303 may be configured
to receive the signals from the change in reference voltage signal when the potentiometer 301 is
operated based on the user rotating the knob on the control unit 100. More specifically, the
driver unit 303 may be configured to receive the reference signal (Rs) from the potentiometer
25 301 based on the changes in voltage parameter. The changes in voltage parameter is a result of
the user rotating the knob and causing variable resistance. Further, a position feedback
signal/voltage reference (Ps) 304 from the actuating motor 203 via the input leads 204 is
received on the driver unit 303, for comparison. Internally, the driver unit 303 receive two
inputs: first from the potentiometer 301 to be called as targeted position input signal or reference
30 voltage signal/input (Rs) and Position feedback signal/voltage (Ps) 304 from the actuating motor
203 to be understood as the present state of the flap 202.
In an example, if the user rotates the knob from the control unit 100, the knob is connected
to the Potentiometer 301. The changes in the knob position, sends the reference voltage which
13
changes as the knob is rotated. On the other hand, the actuating motor 203 is connected in a
manner 305. The actuating motor position feedback reference signal/voltage (Ps) 304 are also
connected with the driver unit 303. The driver unit 303 will start comparing the (Rs) and (Ps)
internally with the hysteresis control 302.
5 If the first signal (Rs) i.e., the reference voltage signal/input from the potentiometer 301 is
greater than the position feedback reference signal/voltage (Ps) 304, then the driver unit 303
transmits an operation signal to the actuating motor 203 to perform counter clockwise rotation. If
reference voltage signal/input (Rs) from potentiometer 301 is less than position feedback signal
(Ps) 304 then the driver unit 303 transmits the operation signal to the actuating motor 203 to
10 perform clockwise rotation.
If (Rs) = (Ps) then with the Hysteresis controller 302 the driver unit 303 will prevent to
send the operation signal to the actuating motor rotation. If the user rotates the input knob
position, then the above steps shall be again implemented in accordance with the invention.
15 Figure 3b illustrates schematic view of a tactile switch operation for generation of an
enable or a disable signal for master ECU, according to an embodiment of the present subject
matter. Figure 3b represents following components: a first power supply (5Volt) 312, a second
power supply or a battery voltage 313, the tactile switch 306, the driver unit 303 acting as a flipflop driver unit, an interfacing component, a terminal device which is a N-Chanel MOSFET 309,
20 a Light emitting Diode (LED) 309. The tactile switch 306 may be configured to transmit the
input signal to driver 314, based on the tactile switch 306 operation input received from the user.
The power supply section may be provided with a protection and filtering circuit to protect it
from the incoming surge and transients, it is connected as 313 and 312 with filter.
25 In an alternative embodiment of the invention, the flip-flop driver unit 303 may be
configured to receive a clock signal 328. The clock signal 328. When the user operates the
control unit 100 and pushes a tactile switch 306 connected to the control unit 100, the clock
signal 328 is generated. More specifically, the flip-flop driver unit 303 may be configured to
receive the clock signals 328 from the tactile switch 306 based on the enable or disable state via
30 connection of the clock pulse lead 314, data input and complementary output leads, combined
with help of interfacing components for creating a logic 307. Now, during operation of the
tactile switch 306 following steps and output is created:
14
When the user presses the tactile switch 306 i.e., the first operation on the tactile switch
306 is performed, the flip-flop driver unit 303 receives the clock signal 328 and determines the
clock signal 328 as a high pulse signal. The high pulse signal received on the flip-flop driver unit
303 generates an output signal 308 for the terminal device 309.
5 This output signal 308 interfaced with the terminal device MOSFET’s 309 and activates
the MOSFET. Upon activation of MOSFET, the power supply from the battery is received 311.
The terminal device MOSFET’s 309 have signal lines 311 connected with the LED 310, and
another signal line goes to the Master ECU 329.
As the tactile switch 306 is pressed for enabling the function by the user, the signal line
10 311 will get voltage and LED 310 will start glowing. The further activation signal is sent to the
master ECU 329 for performing the operation on the HVAC control unit.
In another aspect when the user presses the tactile switch 306 i.e., the second operation on
the tactile switch 306 is performed, the flip-flop driver unit 303 receives the clock signal 328 and
determines the clock signal 328 as a low pulse signal. The low pulse signal received on the flip15 flop driver unit 303 generates the output signal 308 for the terminal device 309. The output
signal 308 during low pulse signal deactivates the terminal device 309, thus deactivating the
LED 310 and sending the deactivation signal to the master ECU 329. The master ECU 329 upon
receiving the deactivating signal then ceases the function of the HVAC control unit.
20 In an alternative embodiment, Figure 3c illustrates a schematic view of air conditioning
(AC) function with blower speed dependency of the HVAC control unit, interfacing with control
unit 100, according to an embodiment of the present subject matter.
Figure 3c may be in communication with the control unit 100 to control the AC ON/OFF
with blower dependency. Figure 3c represents but not limited to following components, a power
25 supply (+5volt) 315, a second power supply (+12volt) 321, a flip-flop driver 319/303, a latch
Key Switch 316, an interfacing component 317, a terminal device as a N-Chanel MOSFET 322,
a LED 324, a blower unit 318, the latch Switch 316 may be configured to transmit the input
signal to the flip flop driver unit 303, based on the latch switch 316 operation input received
from the user. The power supply section may be provided with a protection and filtering circuit
30 to protect it from the incoming surge and transients, it’s connected as 315 and 321 with filter.
In an aspect of the invention, the AC function has dependency over the blower state.
Further, the AC will function only if the blower is in a ON state i.e., speed is equal to a state of 1
15
or more. The AC functions will be auto disabled if the blower is in OFF state i.e., the speed is
equal to the state of 0, according to an embodiment of the present subject matter. Furthermore,
AC functions are highly depended upon on the Blower’s ON or OFF state.
For example, the flip-flop driver unit 303 is connected with the latch switch 316 or a contact5 based switch 316, which are directly responsible to control the blower unit 318 enable or disable
state. The latch switch 316 is connected on the control unit 100 to be operated by the user.
The blower unit 318 is be connected with the flip-flop driver unit 303 and a blower common
terminal. A pre-defined logic is established in the flip-flop driver unit 303 which is:
1. While the blower unit 318 is in OFF State then the common terminal will be in floating
10 condition thus having open circuit.
2. While blower unit 318 is in ON state then the common terminal will be connected to
ground thus having a closed circuit.
In an aspect of the invention, the control unit 100 is connected with the latch switch 316
15 configured for generating a reference signal. The flip flop driver unit 303 receives the reference
signal. More specifically, the flip-flop driver unit 303 may be configured to receive the signals
from latch switch 316 based on the enable or disable state of latch switch 316. The flip-flop
driver unit 303, a Vdd terminal connected with a Vcc Supply 315, a ground terminal or a
common terminal connected with the blower unit 318. A High to low transient signal pulse will
20 be created from latch switch 316 state of enable or disable. The latch switch 306 is connected on
the clock pulse lead 314, a data input and a complementary output leads are combined with help
of interfacing components for creating a logic 307. Now, during operation of latch switch 316
following steps and output is performed.
25 In another aspect of the invention when the reference signal generated by the latch switch
316 in response to the user operating the latch switch 316 to bring the latch switch in disable
state. Then the flip-flop driver unit 303 receives the reference signal and generates an output
signal 324. Thus, the blower unit 318 is switched in OFF state. The flip-flop driver unit 303, the
common terminal 320 or the ground terminal become in floating condition, i.e., the common
30 terminal 320 is configured to open the circuit for deactivation of an air conditioner unit. Due to
this the power supply path is open and the current will not flow in the section 320. The latch
switch 316 will provide the signal to the flip-flop driver unit 303, but the flip-flop driver unit
303 will stay in non-operating environment, i.e., it is not able to detect as well as react. The flip-
16
flop driver unit 303 will remain in the sated condition when the blower is in OFF state or when
the supply is absent. Therefore, it is to be understood that in situation where the blower is turned
OFF, the air conditioner unit will not work.
5 In another aspect of the invention, when the reference signal generated by the latch switch
316 in response to the user operating the latch switch 316 to bring the latch switch in enable
state. Then the flip-flop driver unit 303 receives the reference signal and generates the output
signal. Thus, the blower unit 318 is switched in ON state. The common terminal 320 or the
ground terminal will be interfacing with the blower unit 318 and then the common terminal 320
10 is grounded. The common terminal 320 thus is in closed circuit state for activation of the air
conditioner unit of the HVAC control unit. When the power supply is in closed loop, the flipflop driver unit 303 will found the operating environment.

WE CLAIM:
1. An arrangement for controlling HVAC unit of an automobile, the arrangement
comprising:
a control unit (100) adapted to be operated by a user, wherein the control unit is
5 configured to transmit reference signal (Rs);
a driver unit (303) connected with a power supply (300) and adapted to operate
the HVAC unit, wherein the driver unit (303) is configured to receive reference signal
(Rs);
an actuating motor (203) adapted to change position of at least one flap
10 (201,202), wherein the actuating motor (203) transmits position feedback signal (Ps) to
the driver unit (303);
wherein the driver unit (303) is configured to transmit an operation signal to the
actuating motor (203) based on determining difference between the reference signal (Rs)
and position feedback signal (Ps).
15 2. The arrangement as claimed in claim 1, wherein, the control unit (100) connected with a
potentiometer (301);
wherein the potentiometer (301) is configured for generating a difference in
voltage parameter; and
generating the reference signal (Rs) based on the difference in voltage parameter
20 when the user operates the control unit (100).
3. The arrangement as claimed in claim 1, wherein the driver unit (303) sends the operation
signal:
to rotate actuating motor (203) counter clockwise (410) wherein the reference
signal (Rs) is greater than the position feedback signal (Ps);
25 to rotate actuating motor (203) clockwise (412) wherein the reference signal (Rs)
is smaller than the position feedback signal (Ps);
4. The arrangement as claimed in claim 3, wherein the driver unit (303) is further connected
with a hysteresis controller (302);
18
wherein the reference signal (Rs) is equal to the position feedback signal (Ps), the
hysteresis controller (302) is configured to prevent the driver unit (303) to transmit the
operation signal to the actuating motor (203).
5. An arrangement for controlling HVAC unit of an automobile, the arrangement
5 comprising:
a control unit (100) adapted to be operated by a user, wherein the control unit
(100) is connected with a tactile switch (306) configured to generate a clock signal (328);
a flip-flop driver unit (303) adapted to receiving and determining the clock signal
(328), wherein the flip-flop driver unit (303) is configured to generating an output signal
10 (308) based on the clock signal (328);
a terminal device (309) connected with the flip-flop driver unit (303) and with a
power supply (312), configured to receiving the output signal (308), wherein the terminal
device (309) transmits a signal to a light emitting diode (LED) (310) and a master
electronic circuit unit (ECU) (329) based on the output signal (308).
15 6. The arrangement as claimed in claim 5, wherein the clock signal (328) is a high pulse
signal generated by the tact switch (306) in an enabled state;
wherein the high pulse signal is transmitted to the flip-flop driver unit (303) for
generating the output signal (308) for activating the terminal device (309);
wherein the terminal device (309) transmits the signal for activation of LED
20 (310) and master ECU (329).
7. The arrangement as claimed in claim 5, wherein the clock signal (328) is a low pulse
signal generated by the tact switch (306) in a disabled state;
wherein the low pulse signal is transmitted to the flip-flop driver unit (303) for
generating the output signal (308) for deactivating the terminal device (309);
25 wherein the terminal device (309) transmits the signal for deactivation of LED
(310) and master ECU (329).
8. An arrangement for controlling HVAC unit of an automobile, the arrangement
comprising:
19
a control unit (100) adapted to be operated by a user, wherein the control unit
(100) is connected with a latch switch (316) configured for generating a reference signal;
a flip-flop driver unit (303) connected with the latch switch (316) for receiving
the reference signal, wherein the flip flop driver unit (303) is configured for generating
5 an operating signal;
a blower unit (318) in connection with the flip-flop driver unit (303), adapted to
receive the operating signal.
9. The arrangement as claimed in claim 8, wherein the reference signal is an enable signal,
wherein the flip-flop driver unit (303) generates the operating signal for activating the
10 blower unit (318);
further in a common terminal (320) in connection with the blower unit (318),
wherein the common terminal (320) is configured to close the circuit for activation of an
air conditioner unit.
10. The arrangement as claimed in claim 9, wherein the reference signal is a disable signal,
15 wherein the flip-flop driver unit generates the operating signal for deactivating the
blower unit (318);
further in a common terminal (320) in connection with the blower unit (318),
wherein the common terminal (320) is configured to open the circuit for deactivation of
an air conditioner unit when the blower unit is deactivated.