WO2015052547A1

WO2015052547A1 - Seat heater system and method of operating the same

Info

Publication number: WO2015052547A1
Application number: PCT/IB2013/002254
Authority: WO
Inventors: Lars Planelid
Original assignee: Kongsberg Automotive Ab
Priority date: 2013-10-09
Filing date: 2013-10-09
Publication date: 2015-04-16

Abstract

A seat heater system and method are disclosed. The seat heater system includes a control unit with a switch for transmitting an activation signal and an indicator for receiving an indicator signal. The seat heater system includes a heater unit for receiving the activation signal and transmitting the indicator signal. A transmission line defines a single line of communication between the control unit and the heater unit. The single transmission line operates according to different first and second predetermined voltages. The indicator signal is transmittable when the single transmission line operates according to the first predetermined voltage. The activation signal is transmittable when the single transmission line operates according to the second predetermined voltage. The heater unit selectively toggles operation of the single transmission line between the first and second predetermined voltages such that the heater unit maintains communication with the switch and the indicator through the single transmission line.

Description

SEAT HEATER SYSTEM AND METHOD OF OPERATING THE SAME

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The subject invention generally relates to a seat heater system.

2. Description of Related Art

[0002] Many vehicles currently include systems for providing heating to vehicle seats. Such systems often include a control switch unit for interfacing with an occupant of the vehicle and a heat controller connected to the control switch unit for providing seat heater control. The control switch unit typically has devices, such as switches and LED's. Signals are transmitted or received between the devices in the control switch unit and the heater controller. The devices in the control unit typically transmit or receive different signals because the devices have different operating parameters. Conventional systems require for each device a separate and dedicated line between the control switch unit and the heat controller to avoid signal crossing thereby allowing such devices to transmit or receive different signals. The separate and dedicated line for each device forces the system to have multiple wiring, splicing, and terminals. Therefore, there remains an opportunity to develop a system and method of controlling signal transmission between a control switch unit and a heat controller that is more efficient, costs less and/or has a reduced number of components.

SUMMARY OF THE INVENTION AND ADVANTAGES

[0003] In one embodiment, the subject invention provides a seat heater system including a control unit and a heater unit. The control unit includes a switch configured to transmit an activation signal upon activation of seat heating. The control unit includes an indicator configured to receive an indicator signal upon activation of seat heating for providing a visual indication that seat heating is active. The heater unit is configured to receive the activation signal from the switch for detecting activation of seat heating. The heater unit is configured to transmit the indicator signal to the indicator for enabling the indicator to provide the visual indication that seat heating is active. A transmission line is connected between the control unit and the heater unit such that the transmission line defines a single line of communication between the control unit and the heater unit. The single transmission line is configured to operate according to a first predetermined voltage and a second predetermined voltage. The first predetermined voltage is different than the second predetermined voltage. The indicator signal is transmittable between the control unit and the heater unit when the single transmission line operates according to the first predetermined voltage. The activation signal is transmittable between the control unit and the heater unit when the single transmission line operates according to the second predetermined voltage. The heater unit is configured to selectively toggle the operation of the single transmission line between the first and second predetermined voltages such that the heater unit maintains communication with the switch and the indicator though the single transmission line.

[0004] Additionally, a method of operating a seat heater system is provided. The method includes the step of configuring a single transmission line to operate according to a first predetermined voltage. The method includes transmitting an indicator signal between a heater unit and an indicator in a control unit through the single transmission line to enable the indicator to provide a visual indication that seat heating is active when the single transmission line operates according to the first predetermined voltage. The method includes configuring the single transmission line to operate according to a second predetermined voltage that is different than the first predetermined voltage. The method includes transmitting an activation signal between a switch in the control unit and the heater unit through the single transmission line to activate seat heating when the single transmission line operates according to the second predetermined voltage. The method includes selectively toggling the operations of the single transmission line between the first and second predetermined voltages such that the heater unit maintains communication with the switch and the indicator though the single transmission line.

[0005] Accordingly, the seat heater system and method provide efficient signal transmission between the control unit and the heater unit. By having the single transmission line define a single line of communication between the control unit and the heater unit, separate and dedicated wires between the control unit and the heat controller for the indicator and the switch are no longer required. As such, elimination of additional wiring, splicing, and terminals causes the seat heater system to weigh less and be less expensive. Moreover, the heater unit selectively toggles the operation of the single transmission line between the first and second predetermined voltages such that signals transmitted and received between the control unit and the heater unit are not crossed. By doing so, the seat heater system and method advantageously allow for the indicator and the switch to maintain operation while having different signals.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

[0007] FIG. 1 is a partial interior view of a vehicle with a seat heater system in accordance with the present invention.

[0008] FIG. 2 is a circuit diagram illustrating a control unit, a heater unit, and a single transmission line of the seat heater system in accordance with one embodiment of the subject invention.

[0009] FIG. 3 is a waveform chart illustrating transmission and reception characteristics of an activation signal and an indicator signal in relation to operation of the single transmission line in accordance with one embodiment of the subject invention.

[0010] FIG. 4 is a waveform chart illustrating transmission and reception characteristics of the activation signal and the indicator signal in relation to operation of the single transmission line in accordance with to another embodiment of the present invention.

[0011] FIG. 5 is a circuit diagram illustrating a control unit, heater unit, and single transmission line of a seat heater system in accordance with another embodiment of the present invention.

[0012] FIG. 6 is a waveform chart illustrating transmission and reception characteristics of a first activation signal, a second activation signal, and an indicator signal in relation to operation of a single transmission line in accordance with yet another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a seat heater system is generally shown at 10. As shown in FIG. 1 , the seat heater system 10 includes a control unit 12 and a heater unit 14.

[0014] In one embodiment, the seat heater system 10 is implemented in a vehicle 13 that includes a seat 15. The seat heater system 10 controls heating of the vehicle seat 15. The control unit 12 may be disposed in the vehicle 13 such that an occupant of the vehicle 13 may see and manipulate the control unit 12. The heater unit 14 may be disposed at any suitable location in the vehicle 13, including adjacent to the vehicle seat 15.

[0015] The control unit 12 includes a switch 16 and an indicator 18. In one embodiment, the control unit 12 includes a housing 19 with the switch 16 and the indicator 18 being attached to the housing 19 of the control unit 12. As such, the occupant of the vehicle 13 may have access to manipulate the switch 16 and see the indicator 18.

[0016] The switch 16 is configured to transmit an activation signal. The switch 16 transmits the activation signal upon activation of seat heating. In one embodiment, the switch 16 is defined as a push-button switch for allowing the occupant to activate seat heating. However, the switch 16 may also be any suitable mechanical, electrical, or electro-mechanical switch. Generally, the occupant actuates the switch 16 when the occupant desires seat heating. As such, the occupant of the vehicle 13 activates seat heating such that the switch 16 transmits the activation signal.

[0017] The indicator 18 is configured to receive an indicator signal. The indicator 18 receives the indicator signal upon activation of seat heating. In one embodiment, the indicator 18 receives the indicator signal once the occupant actuates the switch 16 to demand seat heating. The indicator 18 provides a visual indication that seat heating is active. The indicator 18 may be an illumination device for providing the occupant of the vehicle 13 with the visual indication that seat heating is active. In one embodiment, the indicator 18 is defined as a light emitting diode (LED). However, the indicator 18 may be other illumination devices without departing from the scope of the present invention. [0018] As shown in FIG. 2, the switch 16 and the indicator 18 are connected in series in the control unit 12. A first node 22 is defined in the control unit 12 between the switch 16 and the indicator 18.

[0019] A power source 24 is connected to the control unit 12. The power source 24 is typically a 12V DC vehicle battery. However, the power source 24 may be any suitable source of power. For simplicity, the power source 24 is represented by schematic lines in FIGS. 2 and 5. Series-connection between the switch 16 and the indicator 18 allow the power source 24 to have a single connection point for both the switch 16 and the indicator 18. A resistor Rl may be disposed between the power source 24 and the indicator 18 for providing proper operation current to the indicator 18. The power source 24 may be connected to the switch 16 and the indicator 18 in other configurations without departing from the scope of the present invention.

[0020] A ground reference 26 is also connected to the control unit 12. The ground reference 26 is typically vehicle ground including a return path to the vehicle battery. In FIG. 2, series-connection between the switch 16 and the indicator 18 allow the ground reference 26 to have a single connection point for both the switch 16 and the indicator 18. The ground reference 26 may be connected to the switch 16 and the indicator 18 in other configurations without departing from the scope of the present invention.

[0021] The heater unit 14 is configured to receive the activation signal from the switch 16 for detecting activation of seat heating. As shown in FIG. 2, the heater unit 14 includes a processor 30 having an input 32. The input 32 of the processor 30 is configured to receive the activation signal. As such, receiving the activation signal with the heater unit 14 is further defined as receiving the activation signal at the input 32 of the processor 30. As shown through the Figures, reception of the activation signal by the processor 30 is identified by the abbreviation 'Rx' for simplicity.

[0022] As shown in FIG. 2, a heating element 36 is connected to the heater unit 14. The heating element 36 is activated when the heater unit 14 receives the activation signal from the switch 16. The heating element 36 is generally disposed within a cushion or a back of the vehicle seat 15. However, the heating element 36 may be disposed in other locations without departing from the scope of the invention. In one embodiment, the heating element 36 includes at least one conductive wire 38 that generates heat. The conductive wire 38 generates heat at a first temperature when the heater unit 14 receives the activation signal. The conductive wire 38 generates heat at a second temperature that is less than the first temperature when the activation signal is absent. Generally, the second temperature corresponds to the nominal or ambient temperature of the conductive wire 38 when seat heating is inactive.

[0023] In one embodiment, as shown in FIG. 2, the heating element 36 is connected directly to the processor 30. In such configurations, the processor 30 includes suitable components and functionality for receiving the activation signal and energizing the heating element 36. In another embodiment, as shown in FIG. 5, the heating element 36 is connected directly to a second unit 40. The second unit 40 is connected to and in communication with the processor 30. In such configurations, the processor 30 includes suitable components and functionality for receiving the activation signal while the second unit 40 includes suitable components and functionality for energizing the heating element 36.

[0024] The heater unit 14 is configured to transmit the indicator signal to the indicator 18 for enabling the indicator 18 to provide the visual indication that seat heating is active. As shown in FIG. 2, the processor 30 has an output 42. The output 42 of the processor 30 is configured to transmit the indicator signal. As such, transmitting the indicator signal with the heater unit 14 is further defined as transmitting the indicator signal from the output 42 of the processor 30. As shown through the Figures, transmission of the indicator signal by the processor 30 is identified by the abbreviation 'Τχ' for simplicity.

[0025] The heater unit 14 may include any suitable encoder or encoding algorithm for encoding the activation signal and the indicator signal. The encoder may be in communication with the processor 30 or a subcomponent of the processor 30.

[0026] The heater unit 14 includes a transistor 44 connected to the processor 30. The transistor 44 includes an input 46 and an output 48. The input 46 of the transistor 44 is connected to the output 42 of the processor 30. In one embodiment, the transistor 44 is further defined as a bipolar junction transistor having a base, a collector, and an emitter. The input 46 of the transistor 44 is further defined as the base of the transistor 44. The output 48 of the transistor 44 is further defined as the collector and/or emitter of the transistor 44. Resistor R2 is provided between the output 42 of the processor 30 and the input 36 of the transistor 44 for ensuring that proper operating voltage is applied to the base of the transistor 44.

[0027] A second node 50 is defined in the heater unit 14 between the output 48 of the transistor 44 and the input 32 of the processor 30. In particular, the second node 50 is defined between the collector of the transistor 44 and the input 32 of the processor 30. Resistor R3 is provided between the output 48 of the transistor 44 and the second node 50. More specifically, R3 is provided between the collector of the transistor 44 and the second node 50. Resistor R4 is provided between the second node 50 and the input 32 of the processor 30 to ensure proper input current is provided to the input 32 of the processor 30. The heater unit 14 includes resistor R5 that is connected to the second node 50. Resistor R5 functions as a pull-up resistor to allow reception of the activation signal, as will be described below. The second node 50 is defined at a junction between the input 32 of the processor 30, the output 48 of the transistor 44, and the pull-up resistor R5. Said differently, resistors R3, R4, and R5 join at the second node 50.

[0028] The power source 24 is connected to the heater unit 14. In FIG. 2, the power source 24 is connected to the processor 30 and to the pull-up resistor R5. In FIG. 5, the power source 24 is connected to the second unit 40 for providing the second unit 40 with sufficient power to energize the heating element 36. In such instances, the processor 30 may borrow power from the second unit 40 or include a separate power source. Alternatively, the power source 24 may be connected directly to processor 30.

[0029] The ground reference 26 is also connected to the heater unit 14. The processor 30 and/or the second unit 40 may be connected to the ground reference 26 as shown in FIGS. 2 and 5. In FIG. 2, the transistor 44 is connected to the ground reference 26. More specifically, the emitter of the transistor 44 is connected to the ground reference 26.

[0030] The seat heater system 10 includes a transmission line 60 connected between the control unit 12 and the heater unit 14. The transmission line 60 defines a single line of communication between the control unit 12 and the heater unit 14. As shown in FIGS. 2 and 5, the single transmission line 60 has a control unit end 62 and a heater unit end 64. The control unit end 62 is connected to the first node 22 in the control unit 12. The heater unit end 64 is connected to the second node 50 in the heater unit 14. [0031] The single transmission line 60 is configured to operate according to a first predetermined voltage VI and a second predetermined voltage V2. The first predetermined voltage VI is different than the second predetermined voltage V2.

[0032] As shown in FIGS. 3 and 4, the indicator signal is transmittable between the control unit 12 and the heater unit 14 when the single transmission line 60 operates according to the first predetermined voltage VI . In one example, it may be understood that the heater unit 14 enables the indicator signal to transmit between the control unit 12 and the heater unit 14 by forcing the single transmission line 60 to operate according to the first predetermined voltage VI . The terminology "transmittable between" is not intended to limit transmission of the indicator signal to any single direction in relation to the control unit 12 and heater unit 14. Rather, the current passing through the indicator 18 may pass from the control unit 12 to the heater unit 14, and vice- versa, without departing from the scope of the invention. In FIGS. 3 and 4, the indicator signal is transmittable when the amplitude of the waveform associated with the indicator signal is raised to the Tx line.

[0033] The activation signal is transmittable between the control unit 12 and the heater unit 14 when the single transmission line 60 operates according to the second predetermined voltage V2. In one example, it may be understood that the heater unit 14 enables the activation signal to transmit between the control unit 12 and the heater unit 14 by forcing the single transmission line 60 to operate according to the second predetermined voltage V2. The terminology "transmittable between" is not intended to limit transmission of the activation signal to any single direction in relation to the control unit 12 and heater unit 14. Instead, the current passing through the switch 16 may pass from the heater unit 14 to the control unit 12, and vice-versa, without departing from the scope of the invention. In FIGS. 3 and 4, the activation signal is receivable at the heater unit 14 when the amplitude of the waveform associated with the activation signal is raised to the Rx line.

[0034] In one embodiment, the first predetermined voltage VI is less than the second predetermined voltage V2. In such instances, the single transmission line 60 is set at a low-state and a high-state. The low-state corresponds to when the single transmission line 60 is configured to operate according to a first predetermined voltage VI . In other words, the single transmission line 60 is set "low" to when the single transmission line 60 operates according to the first predetermined voltage VI . The high-state corresponds to when the single transmission line 60 is configured to operate according to a second predetermined voltage V2. In other words, the single transmission line 60 is set "high" when the single transmission line 60 operates according to the second predetermined voltage V2. It is to be appreciated that the waveforms of the activation and indicator signals as shown in FIGS. 3 and 4 may be vertically inverted such that transmission and/or reception occurs when the amplitude of the respective waveforms are lowered, rather than raised.

[0035] The heater unit 14 is configured to selectively toggle the operation of the single transmission line 60 between the first predetermined voltage VI and the second predetermined voltage V2. By doing so, the heater unit 14 maintains communication with the switch 16 and the indicator 18 though the single transmission line 60. In one embodiment, the single transmission line 60 may be understood as multiplexed, and more specifically, time or time-division multiplexed (TDM).

[0036] The heater unit 14 may repeatedly toggle operation of the transmission line 60 between the first and second voltages V 1 , V2 according to a predetermined frequency. In one embodiment, the predetermined frequency is purposefully selected to exceed the threshold frequency response of the human eye, which is typically 60 Hz. For instance, the predetermined frequency may be 100 Hz. By exceeding the threshold frequency response of the human eye, intermittent operation of the switch 16 or indicator 18 is not easily visible to the occupant.

[0037] In the embodiments shown in FIGS. 2 and 5, the processor 30 in the heater unit 14 selectively toggles the operation of the single transmission line 60 between the first and second predetermined voltages VI , V2. The processor 30 may repeatedly toggle operation of the transmission line 60 between the first and second voltages VI, V2 according to the predetermined frequency. Toggling the single transmission line 60 between the first and second predetermined voltages VI, V2 is illustrated by the uppermost waveform in FIG. 3.

[0038] The processor 30 is configured to activate the output 48 of the transistor 44 such that the single transmission line 60 operates according to the first predetermined voltage V 1. In operation, the output 42 of the processor 30 applies a first voltage at the input 46 of the transistor 44 to activate the output 48 of the transistor 44. When the output 48 of the transistor 44 is activated, the transistor 44 closes the line between the collector and emitter of the transistor 44. In other words, when the output 48 of the transistor 44 is activated, the line between resistor R3 and the ground reference 26 becomes a closed circuit. As such, a first potential is defined from the power source 24 at resistor Rl in the control unit 12 to the ground reference 26 connected to transistor 44 in the heater unit 14. Creation of this first potential causes the single transmission line 60 to operate according to the first predetermined voltage V 1. Accordingly, current flows from the power source 24 in the control unit 12 to the ground reference 26 in the heater unit 14 thereby allowing transmission of the indicator signal.

[0039] The processor 30 is configured to deactivate the output 48 of transistor 44 such that the single transmission line 60 operates according to the second predetermined voltage V2. In operation, the output 42 of the processor 30 applies a second voltage at the input 46 of the transistor 44 to deactivate the output 48 of the transistor 44. When the output 48 of the transistor 44 is deactivated, the transistor 44 opens the line between the collector and emitter of the transistor 44. In other words, when the output 48 of the transistor 44 is deactivated, the line between resistor R3 and the ground reference 26 becomes an open circuit and current rio longer flows through resistor R3. The pull-up resistor R5 is configured to force the single transmission line 60 to operate according to the second predetermined voltage V2. The pull-up resistor R5 is selected to have a resistance that is generally much less than resistor Rl at the indicator 18. As such, the pull-up resistor R5 ensures that current flows from the power source 24 at the pull-up resistor R5, rather than at resistor Rl . Thus, when the switch 16 is closed, a second potential is defined from the power source 24 at the pull-up resistor Rl the in the heater unit 14 to the ground reference 26 connected to the switch 16 in the control unit 12. Creation of this second potential causes the single transmission line 60 to operate according to the second predetermined voltage V2. Current flows from the power source 24 in heater unit 14 to the ground reference 26 in the control unit 12 thereby allowing transmission of the activation signal. The input 32 to the processor 30 is connected to the second node 50 to tap into the line between pull-up resistor Rl and the ground reference 26 connected to the switch 16 in the control unit 12. As such, the processor 30 detects transmission of the activation signal.

[0040] In one embodiment, as shown in FIG. 4, the heater unit 14 is configured to prioritize reception of the activation signal over transmission of the indicator signal. As established above, the heater unit 14, and more specifically, the processor 30, selectively toggles the operation of the single transmission line 60 between the first and second predetermined voltages VI, V2 to transmit the indicator signal and detect the activation signal. Once the activation signal is detected at the input 32 of the processor 30, the heater unit 14 holds the operation of the single transmission line 60 at the second predetermined voltage V2, as shown in FIG. 4. By continuously holding the single transmission line 60 at the second predetermined voltage V2, the heater unit 14 continuously receives the activation signal. In such instances, the heater unit 14 may cease to repeatedly toggle operation between the first and second voltages VI, V2 according to the predetermined frequency. In some instances, as shown in FIG. 4, transmission of the indicator signal is largely suppressed because the single transmission line 60 is dedicated to the activation signal. In FIG. 4, prioritization of the activation signal suppresses the amplitude of the square-waveform for the indicator signal such that the indicator signal never reaches meaningful transmission. Alternatively, transmission of the indicator signal may be entirely suppressed.

[0041] In one embodiment, as shown in FIG. 5, the seat heater system 10 further includes a second switch 70 in the control unit 12. The second switch 70 is configured to transmit a second activation signal that is different than the first activation signal corresponding to the first switch 16. The heater unit 14 is configured to receive the second activation signal from the second switch 70. The single transmission line 60 is configured to operate according to a third predetermined V3 that is different than the first and second predetermined voltages V 1 , V2. The second activation signal is transmittable between the control unit 12 and the heater unit 14 when the single transmission line 60 operates according to the third predetermined voltage V3.

[0042] As shown in FIG. 6, the heater unit 14 is configured to selectively toggle the operation of the single transmission line 60 between the first, second, and third predetermined voltages VI , V2, V3. By doing so, the heater unit 14 maintains communication with the first switch 16, the second switch 70, and the indicator 18 though the single transmission line 60. As shown in the uppermost waveform in FIG. 6, the operation of the transmission line 60 is continuously toggled between the first, second, and third voltages VI, V2, V3 according to the predetermined frequency. For simplicity, reception of the first activation signal is identified by the abbreviation 'Rx 1 reception of the second activation signal is identified by the abbreviation 'Rx2,' and transmission of the indicator signal is identified by the abbreviation 'Tx.'

[0043] In FIG. 5, resistor R6 is disposed between the first switch 16 and the first node 22. Resistor R7 is disposed between the second switch 70 and the first node 22. Resistor R8 is disposed between the indicator 18 and the first node 22. Resistors R6, R7, and R8 are of different resistive values to allow the single transmission line 60 to operate according to either the first, second or third predetermined voltages VI, V2, V3. Resistors R6 and R7 further allow the processor 30 to distinguish between the first and second activation signals. In operation, the processor 30 activates and deactivates the transistor 44, as established above. The current received at the input 32 of the processor 30 will be different depending on whether the first switch 16 or the second switch 70 is actuated. The heater unit 14 may be configured to prioritize reception of the first and/or second activation signals over transmission of the indicator signal.

[0044] The control unit 12 may further include a switch back light 80, as shown in FIG. 5. The switch back light 80 provides illumination to the first switch 16 for allowing the occupant of the vehicle 13 to readily see the first switch 16. The switch back light 80 may also provide illumination to the second switch 70. The switch back light 80 may be any suitable illumination device. In FIG. 5, the switch back light 80 is further defined as an LED. The switch back light 80 is connected to the power source 24 and the ground reference 26. A resistor R9 is disposed between the power source 24 and the switch backlight 80 for providing proper input current to the switch back light 80. A third node 82 is defined in the control unit 12 between the switch back light 80, the first switch 16, and the ground reference 26. The control unit 12 may include additional circuitry or functionality not specifically described herein without departing from the scope of the present invention. [0045] A method of operating the seat heater system 10 is further provided. The method includes the step of configuring the single transmission line 60 to operate according to the first predetermined voltage VI . The method includes transmitting the indicator signal between the heater unit 14 and the indicator 18 in the control unit 12 through the single transmission line 60 to enable the indicator 18 to provide the visual indication that seat heating is active when the single transmission line 60 operates according to the first predetermined voltage VI . The method includes configuring the single transmission line 60 to operate according to the second predetermined voltage V2 that is different than the first predetermined voltage VI . The method includes transmitting the activation signal between the switch 16 in the control unit 12 and the heater unit 14 through the single transmission line 60 to activate seat heating when the single transmission line 60 operates according to the second predetermined voltage V2. The method further includes selectively toggling the operations of the single transmission line 60 between the first and second predetermined voltages VI, V2 such that the heater unit 14 maintains communication with the switch 16 and the indicator 18 though the single transmission line 60.

[0046] The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. As is now apparent to those skilled in the art, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

Claims

CLAIMS What is claimed is:

1. A seat heater system comprising:

a control unit comprising a switch configured to transmit an activation signal upon activation of seat heating and an indicator configured to receive an indicator signal upon activation of seat heating for providing a visual indication that seat heating is active; a heater unit configured to receive said activation signal from said switch for detecting activation of seat heating and transmit said indicator signal to said indicator for enabling said indicator to provide said visual indication that seat heating is active; and a transmission line connected between said control unit and said heater unit such that said transmission line defines a single line of communication between said control unit and said heater unit and with said single transmission line being configured to operate according to a first predetermined voltage and a second predetermined voltage with said first predetermined voltage being different than said second predetermined voltage;

said indicator signal being transmittable between said control unit and said heater unit when said single transmission line operates according to said first predetermined voltage and said activation signal being transmittable between said control unit and said heater unit when said single transmission line operates according to said second predetermined voltage; and

said heater unit being configured to selectively toggle said operation of said single transmission line between said first and second predetermined voltages such that said heater unit maintains communication with said switch and said indicator though said single transmission line.

2. The seat heater system of claim 1 , wherein said first predetermined voltage is less than said second predetermined voltage.

3. The seat heater system of any preceding claim, wherein said heater unit is configured to prioritize reception of said activation signal over transmission of said indicator signal.

4. The seat heater system of any preceding claim, further including a heating element connected to said heater unit and being activated when said heater unit receives said activation signal from said switch.

5. The seat heater system of claim 4, wherein said heating element includes at least one conductive wire that generates heat at a first temperature when said heater unit receives said activation signal and a second temperature when said activation signal is absent, wherein said first temperature is greater than said second temperature.

6. The seat heater system of any preceding claim wherein said switch is further defined as a push-button switch for allowing an occupant to activate seat heating.

7. The seat heater system of any preceding claim wherein said indicator is further defined as an illumination device for providing an occupant with said visual indication that seat heating is active.

8. The seat heater system of any preceding claim, wherein said heater unit includes a processor having an input and an output with said input of said processor being configured to receive said activation signal and said output of said processor being configured to transmit said indicator signal.

9. The seat heater system of claim 8, wherein said heater unit includes a transistor having an input and an output with said input of said transistor being connected to said output of said processor.

10. The seat heater system of any preceding claim, wherein a first node is defined between said switch and said indicator in said control unit.

1 1. The seat heater system of claim 9, wherein a second node is defined in said heater unit between said output of said transistor and said input of said processor.

12. The seat heater system of claim 1 1, wherein said single transmission line has a control unit end and a heater unit end with said control unit end being connected to said first node in said control unit and said heater unit end being connected to said second node in said heater unit.

13. The seat heater system of any one of claims 9-12, wherein said processor is configured to activate said output of said transistor such that said single transmission line operates according to said first predetermined voltage.

14. The seat heater system of any one of claims 9-13, wherein said processor is configured to deactivate said output of transistor such that said single transmission line operates according to said second predetermined voltage.

15. The seat heater system of any one of claims 1 1-14, wherein said heater unit includes a pull-up resistor connected to said second node with said pull-up resistor being configured to force said single transmission line to operate according to said second predetermined voltage when said processor deactivates said output of said transistor.

16. The seat heater system of any preceding claim further comprising a second switch in said control unit being configured to transmit a second activation signal with said heater unit being configured to receive said second activation signal from said second switch and with said single transmission line being configured to operate according to a third predetermined being different than said first and second predetermined voltages and said second activation signal being transmittable between said control unit and said heater unit when said single transmission line operates according to said third predetermined voltage, wherein said heater unit is configured to selectively toggle said operation of said single transmission line between said first, second, and third predetermined voltages such that said heater unit maintains communication with said switch , said second switch, and said indicator though said single transmission line.

17. A seat heater system comprising:

a control unit including a switch to activate seat heating and an indicator to provide a visual indication that seat heating is active with said switch and said indicator being connected in series and with a first node being defined in said control unit between said switch and said indicator;

a heater unit including a processor having an input and an output, a transistor having an input and an output, and a pull-up resistor and with said output of said processor being connected to said input of said transistor and with a second node being defined in said heater unit between said input of said processor, said output of said transistor, and said pull-up resistor; and

a transmission line connected between said control unit and said heater unit to define a single line of communication between said control unit and said heater unit with said single transmission line having a control unit end and a heater unit end with said control unit end being connected to said first node in said control unit and said heater unit end being connected to said second node in said heater unit.

18. A method of operating a seat heater system, the seat heater system comprising a control unit including a switch and an indicator, a heater unit, and a single transmission line connected between the control unit and the heater unit, said method comprising the steps of:

configuring the single transmission line to operate according to a first predetermined voltage;

transmitting an indicator signal between the heater unit and the indicator in the control unit through the single transmission line to enable the indicator to provide a visual indication that seat heating is active when the single transmission line operates according to the first predetermined voltage;

configuring the single transmission line to operate according to a second predetermined voltage that is different than the first predetermined voltage;

transmitting an activation signal between the switch in the control unit and the heater unit through the single transmission line to activate seat heating when the single transmission line operates according to the second predetermined voltage; and

selectively toggling the operations of the single transmission line between the first and second predetermined voltages such that the heater unit maintains communication with the switch and the indicator though the single transmission line.

19. The method of claim 18, further comprising prioritizing reception of the activation signal over transmission of the indicator signal by holding the operation of said single transmission line at the second predetermined voltage such that said heater unit continuously receives said activation signal.

20. The method of any one of claims 18 and 19, wherein the heater unit includes a processor having an input and an output and further comprising the step of receiving the activation signal at the input of the processor.

21. The method of claim 20 wherein the step of transmitting the indicator signal is further defined as transmitting the indicator signal from the output of the processor.

22. The method of claim 21 , wherein the heater unit includes a transistor having an input and an output with the input of the transistor being connected to the output of the processor and with a first node being defined in the heater unit between the output of the transistor and the input of the processor, wherein the step of configuring the single transmission line to operate according to the first predetermined voltage is further defined as activating the output of the transistor with the processor such that the single transmission line operates according to the first predetermined voltage.

23. The method of claim 22, wherein the heater unit includes a pull-up resistor connected to the first node, wherein the step of configuring the single transmission line to operate according to the second predetermined voltage is further defined as:

deactivating the output of transistor; and

utilizing the pull-up resistor to allow the single transmission line to operate according to the second predetermined voltage.