Abstract:
A touch dimmer has a three-wire touch sensitive screen that produces an output voltage signal representative of a position of a manual pressure touch along a longitudinal axis of the touch screen. To reduce the occurrence of erroneous position indications due to low-pressure touches of the touch screen, a filter circuit is coupled to the output of the touch screen to prevent the detection of transient touches, and to prevent the detection of low-pressure touches having less than a certain actuation force. As a result, a controller may accurately determine the position of the manual pressure touch. In a preferred embodiment, two filters are coupled to the output of the touch screen. The first filter conditions the output voltage signal to allow the controller to accurately determine whether a manual pressure touch actuation has occurred. The second filter conditions the output voltage signal to allow the controller to accurately determine the position of the manual pressure touch along a longitudinal axis of the touch screen. An alternative embodiment of the touch dimmer uses a four-wire touch sensitive screen that produces a second output voltage signal representative of a position of a manual pressure touch along a transverse axis of the touch screen. The first filter is coupled to receive the second output signal to permit accurate detection of a manual pressure touch actuation.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to load control devices for controlling the amount of power delivered to an electrical load from a power source. More specifically, the present invention relates to a touch dimmer having a touch sensitive device. 
         [0003]    2. Description of the Related Art 
         [0004]    A conventional two-wire dimmer has two terminals: a “hot” terminal for connection to an alternating-current (AC) power supply and a “dimmed hot” terminal for connection to a lighting load. Standard dimmers use one or more semiconductor switches, such as triacs or field effect transistors (FETs), to control the current delivered to the lighting load and thus to control the intensity of the light. The semiconductor switches are typically coupled between the hot and dimmed hot terminals of the dimmer. 
         [0005]    Smart wall-mounted dimmers include a user interface typically having a plurality of buttons for receiving inputs from a user and a plurality of status indicators for providing feedback to the user. These smart dimmers typically include a microcontroller or other processing device for providing an advanced set of control features and feedback options to the end user. An example of a smart dimmer is described in greater detail in commonly assigned U.S. Pat. No. 5,248,919, issued on Sep. 28, 1993, entitled LIGHTING CONTROL DEVICE, which is herein incorporated by reference in its entirety. 
         [0006]      FIG. 1  is a front view of a user interface of a prior art smart dimmer switch  10  for controlling the amount of power delivered from a source of AC power to a lighting load. As shown, the dimmer switch  10  includes a faceplate  12 , a bezel  14 , an intensity selection actuator  16  for selecting a desired level of light intensity of a lighting load (not shown) controlled by the dimmer switch  10 , and a control switch actuator  18 . Actuation of the upper portion  16 A of the intensity selection actuator  16  increases or raises the light intensity of the lighting load, while actuation of the lower portion  16 B of the intensity selection actuator  16  decreases or lowers the light intensity. The intensity selection actuator  16  may control a rocker switch, two separate push switches, or the like. The control switch actuator  18  may control a push switch or any other suitable type of actuator and typically provides tactile and auditory feedback to a user when pressed. 
         [0007]    The smart dimmer  10  also includes an intensity level indicator in the form of a plurality of light sources  20 , such as light-emitting diodes (LEDs). Light sources  20  may be arranged in an array (such as a linear array as shown) representative of a range of light intensity levels of the lighting load being controlled. The intensity level of the lighting load may range from a minimum intensity level, which is preferably the lowest visible intensity, but which may be zero, or “full off,” to a maximum intensity level, which is typically “full on.” Light intensity level is typically expressed as a percentage of full intensity. Thus, when the lighting load is on, light intensity level may range from 1% to 100%. 
         [0008]    By illuminating a selected one of the light sources  20  depending upon light intensity level, the position of the illuminated light source within the array provides a visual indication of the light intensity relative to the range when the lamp or lamps being controlled are on. For example, seven LEDs are illustrated in  FIG. 1 . Illuminating the uppermost LED in the array will give an indication that the light intensity level is at or near maximum. Illuminating the center LED will give an indication that the light intensity level is at about the midpoint of the range. In addition, when the lamp or lamps being controlled are off, all of the light sources  18  are illuminated at a low level of illumination, while the LED representative of the present intensity level in the on state is illuminated at a higher illumination level. This enables the light source array to be more readily perceived by the eye in a darkened environment, which assists a user in locating the switch in a dark room, for example, in order to actuate the switch to control the lights in the room, and provides sufficient contrast between the level-indicating LED and the remaining LEDs to enable a user to perceive the relative intensity level at a glance. 
         [0009]    Touch dimmers (or “zip” dimmers) are known in the art. A touch dimmer generally includes a touch-operated input device, such as a resistive or a capacitive touch pad. The touch-operated device responds to the force and position of a point actuation on the surface of the device and in turn controls the semiconductor switches of the dimmer. An example of a touch dimmer is described in greater detail in commonly-assigned U.S. Pat. No. 5,196,782, issued Mar. 23, 1993, entitled TOUCH-OPERATED POWER CONTROL, the entire disclosure of which is hereby incorporated by reference. 
         [0010]      FIG. 2  is a cross-sectional view of a prior art touch-operated device  30 , specifically, a membrane voltage divider. A conductive element  32  and a resistive element  34  are co-extensively supported in close proximity by a spacing frame  36 . An input voltage, V IN , is applied across the resistive element  34  to provide a voltage gradient across its surface. When pressure is applied at a point  38  along the conductive element  32  (by a finger or the like), the conductive element flexes downward and electrically contacts a corresponding point along the surface of the resistive element  34 , providing an output voltage, V OUT , whose value is between the input voltage V IN  and ground. When pressure is released, the conductive element  32  recovers its original shape and becomes electrically isolated from the resistive element  34 . The touch-operated device  30  is characterized by a contact resistance R CONTACT  between the conductive element  32  and the resistive element  34 . The contact resistance R CONTACT  is dependent upon the force of the actuation of the touch-operated device  30  and is typically substantially small for a normal actuation force. 
         [0011]      FIG. 3  is a perspective view of a user interface of a prior art touch dimmer  40 . The dimmer  40  comprises a touch-operated device  30 , which is located directly behind a faceplate  42 . The faceplate  42  includes a flexible area  44  located directly above the conductive element  32  of the touch-operated device  30  to permit a user to actuate the touch-operated device through the faceplate  42 . A conventional phase-control dimming circuit is located within an enclosure  46  and controls the power from a source to a load in accordance with pressure applied to a selectable point on flexible area  44 . The faceplate  42  may include optional markings  48 ,  50 ,  52  to indicate, respectively, the location of flexible area  44 , the lowest achievable intensity level of the load, and location of a “power off” control. An optional LED array  54  provides a visual indication of intensity level of the load. When the load is a light source, there is preferably a linear relationship between the number of illuminated LEDs and the corresponding perceived light level. The flexible area  44  may optionally include a light transmissive area through which LED array  54  is visible. 
         [0012]    It is desirable to provide a touch dimmer that is responsive to only the position of an actuation on the operational area, e.g., the flexible area  44  of the touch dimmer  40 . However, most prior art touch dimmers are responsive to both the force and the position of a point actuation. For example, when a user lightly presses the touch-operated device  30 , i.e., with a low actuation force, the contact resistance R CONTACT  is substantially larger than during a normal actuation. Accordingly, the output of the touch-operated device  30  is not representative of the position of the actuation and the dimmer  40  may control the lighting load to an undesired intensity level. Therefore, there is a need for a touch dimmer having an operational area that is not responsive to light touches and is responsive to only the position of a point actuation. 
       SUMMARY OF THE INVENTION 
       [0013]    According to the present invention, a load control device for controlling the amount of power delivered to an electrical load from an AC power source, comprises a semiconductor switch, a controller, a touch sensitive actuator, and a stabilizing circuit. The semiconductor switch is operable to be coupled in series electrical connection between the source and the load, the semiconductor switch having a control input for controlling the semiconductor switch between a non-conductive state and a conductive state. The controller is operatively coupled to the control input of the semiconductor switch for controlling the semiconductor switch between the non-conductive state and the conductive state. The touch sensitive actuator has a touch sensitive front surface responsive to a point actuation characterized by a position and a force. The touch sensitive actuator has an output operatively coupled to the controller for providing a control signal to the controller. The stabilizing circuit is coupled to the output of the touch sensitive actuator. The control signal is responsive only to the position of the point actuation. 
         [0014]    According to a second embodiment of the present invention, a load control device for controlling the amount of power delivered to an electrical load from an AC power source, the load control device comprises a semiconductor switch, a controller, a touch sensitive actuator, a usage detection circuit, and a stabilizing circuit. The semiconductor switch is operable to be coupled in series electrical connection between the source and the load. The semiconductor switch has a control input for controlling the semiconductor switch between a non-conductive state and a conductive state. The controller is operatively coupled to the control input of the semiconductor switch for controlling the semiconductor switch between the non-conductive state and the conductive state. The touch sensitive actuator having a touch sensitive front surface responsive to a point actuation characterized by a position and a force, the touch sensitive actuator having an output for providing a control signal. The usage detection circuit is operatively coupled between the output of the touch sensitive actuator and the controller for determining whether the point actuation is presently occurring. The stabilizing circuit is operatively coupled between the output of the touch sensitive actuator and the controller for stabilizing the control signal from the output of the touch sensitive actuator. The controller is responsive to the control signal when the usage detection circuit has determined that the point actuation is presently occurring. 
         [0015]    According to another aspect of the present invention, in a control circuit for operating an electrical load in response to an output signal from a touch pad, said touch pad comprising an elongated manually touchable resistive area which produces an output signal at an output terminal, said signal representative of the location at which the touch pad is manually touched, said control circuit including a microprocessor having an input connected to said output signal and producing an output for controlling said load in response to the manual input to said touch pad, the improvement comprising a filter capacitor connected between said output terminal and a ground terminal to define a resistive-capacitive circuit with the resistance of said touch pad, said resistive-capacitive circuit characterized by a time constant and being adapted to prevent large transient voltage changes due to low pressure touches of said touch pad. 
         [0016]    Further, in a manually operable control structure for producing an electrical signal dependent on the location at which a touch screen is touched; said control structure comprising a resistive touch screen having a control voltage connected to terminals at its opposite ends and an output terminal which is connected to said touch screen at the location of a local manual pressure applied to said screen by a user; a microprocessor having an input connected to said output terminal and producing an output related to the position at which said screen receives said local manual pressure; the improvement which comprises a filter capacitor connected between said output terminal and a ground terminal and defining an R/C circuit with the resistance of said touch screen between said position at which said screen receives local manual pressure and one of its said terminals. 
         [0017]    In addition, the present invention provides a process for generating an operating signal from a resistive touch screen in which an output voltage on a output terminal is related to both the location on the screen area which is touched by a users finger and to the pressure of the touch; said process comprising the production of an x signal in response to the touching of said screen at any location on its surface and the production of a y signal in response to the location at which the screen is touched, and applying said x and y signals to a microprocessor; said microprocessor producing an output signal to a circuit to be controlled only when an x output signal is present and a y output signal is also present at the end of a predetermined sample interval. 
         [0018]    Other features and advantages of the present invention will become apparent from the following description of the invention that refers to the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a front view of a user interface of a prior art dimmer; 
           [0020]      FIG. 2  is a cross-sectional view of a prior art touch-operated device; 
           [0021]      FIG. 3  is a perspective view of a user interface of a prior art touch dimmer; 
           [0022]      FIG. 4A  is a perspective view of a touch dimmer according to the present invention; 
           [0023]      FIG. 4B  is a front view of the touch dimmer of  FIG. 4A ; 
           [0024]      FIG. 5A  is a partial assembled sectional view of a bezel and the touch sensitive device of the touch dimmer of  FIG. 4A ; 
           [0025]      FIG. 5B  is a partial exploded sectional view of the bezel and the touch sensitive device of  FIG. 5A ; 
           [0026]      FIG. 6  shows the force profiles of the components and a cumulative force profile of the touch dimmer of  FIG. 4A ; 
           [0027]      FIG. 7  is a simplified block diagram of the touch dimmer of  FIG. 4A ; 
           [0028]      FIG. 8  is a simplified schematic diagram of a stabilizing circuit and a usage detection circuit of the touch dimmer of  FIG. 7  according to a first embodiment of the present invention; 
           [0029]      FIG. 9  is a simplified schematic diagram of an audible sound generator of the touch dimmer of  FIG. 7 ; 
           [0030]      FIG. 10  is a flowchart of a touch dimmer procedure executed by a controller of the dimmer of  FIG. 4A ; 
           [0031]      FIG. 11  is a flowchart of an Idle procedure of the touch dimmer procedure of  FIG. 10 ; 
           [0032]      FIGS. 12A and 12B  are flowcharts of an ActiveHold procedure of the touch dimmer procedure of  FIG. 10 ; 
           [0033]      FIG. 13  is a flowchart of a Release procedure of the touch dimmer procedure of  FIG. 10 ; 
           [0034]      FIGS. 14A and 14B  are simplified schematic diagrams of the circuitry for a four wire touch sensitive device and a controller of the touch dimmer of  FIG. 4A  according to a second embodiment of the present invention; 
           [0035]      FIG. 15A  is a simplified schematic diagram of the circuitry for a four wire touch sensitive device and a controller of the touch dimmer of  FIG. 4A  according to a third embodiment of the present invention; 
           [0036]      FIG. 15B  is a simplified block diagram of a dimmer according to a fourth embodiment of the present invention; 
           [0037]      FIG. 15C  is a simplified schematic diagram of the circuitry for a three-wire touch sensitive device and a controller of the dimmer of  FIG. 15B . 
           [0038]      FIG. 16A  is a perspective view of a touch dimmer according to a fifth embodiment of the present invention; 
           [0039]      FIG. 16B  is a front view of the touch dimmer of  FIG. 16A ; 
           [0040]      FIG. 17A  is a bottom cross-sectional view of the touch dimmer of  FIG. 16B ; 
           [0041]      FIG. 17B  is an enlarged partial view of the bottom cross-sectional view of  FIG. 17A ; 
           [0042]      FIG. 18A  is a left side cross-sectional view of the touch dimmer of  FIG. 16B ; 
           [0043]      FIG. 18B  is an enlarged partial view of the left side cross-sectional view  FIG. 18A ; 
           [0044]      FIG. 19  is a perspective view of a display printed circuit board of the dimmer of  FIG. 16A ; and 
           [0045]      FIG. 20  is an enlarged partial bottom cross-sectional view of a thin touch sensitive actuator according to a sixth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0046]    The foregoing summary, as well as the following detailed description of the preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purposes of illustrating the invention, there is shown in the drawings an embodiment that is presently preferred, in which like numerals represent similar parts throughout the several views of the drawings, it being understood, however, that the invention is not limited to the specific methods and instrumentalities disclosed. 
         [0047]      FIGS. 4A and 4B  are a perspective view and a front view, respectively, of a touch dimmer  100  according to the present invention. The dimmer  100  includes a faceplate  102 , i.e., a cover plate, having a planar front surface  103  and an opening  104 . The opening  104  may define a standard industry-defined opening, such as a traditional opening or a decorator opening, or another uniquely-sized opening as shown in  FIG. 4A . A bezel  106  having a planar touch sensitive front surface  108  extends through the opening  104  of the faceplate  102 . The front surface  108  of the bezel  106  is positioned immediately above a touch sensitive device  110  (shown in  FIGS. 5A and 5B ), i.e., a touch sensitive element, such that a user of the dimmer  100  actuates the touch sensitive element  110  by pressing the front surface  108  of the bezel  106 . As shown in  FIG. 4A , the front surface  108  of the bezel  106  is substantially flush with the front surface  103  of the faceplate  102 , i.e., the plane of the front surface  108  of the bezel  106  is coplanar with the plane of the front surface  103  of the faceplate  102 . However, the bezel  106  may extend through the opening  104  of the faceplate  102  such that the front surface  108  of the bezel is provided in a plane above the plane of the front surface  103  of the faceplate  102 . The faceplate  102  is connected to an adapter  109 , which is connected to a yoke (not shown). The yoke is adapted to mount the dimmer  100  to a standard electrical wallbox. 
         [0048]    The dimmer  100  further comprises a visual display, e.g., a plurality of status markers  112  provided in a linear array along an edge of the front surface  108  of the bezel  106 . The status markers  112  are preferably illuminated from behind by status indicators  114 , e.g., light-emitting diodes (LEDs), located internal to the dimmer  100  (see  FIG. 7 ). The dimmer  100  preferably comprises a light pipe (not shown) having a plurality of light conductors to conduct the light from the status indicators  114  inside the dimmer to the markers  112  on the front surface  108  of the bezel  106 . The status indicators  114  behind the markers  112  are preferably blue. As shown in  FIGS. 4A and 4B , the dimmer  100  comprises seven (7) status markers  112 . However, the dimmer  100  may comprise any number of status markers. Further, the status markers  112  may be disposed in a vertical linear array along the center of the front surface  108  of the bezel  106 . The markers  112  may comprise shadows apparent on the front surface  108  due to voids behind the front surface. 
         [0049]    The front surface  108  of the bezel  106  further includes an icon  116 . The icon  116  may be any sort of visual marker, such as, for example, a dot. Upon actuation of the lower portion of the front surface  108  surrounding the icon  116 , the dimmer  100  causes a connected lighting load  208  ( FIG. 7 ) to change from on to off (and vice versa), i.e., to toggle. Preferably, a blue status indicator and an orange status indicator are located immediately behind the icon  116 , such that the icon  116  is illuminated with blue light when the lighting load  208  is on and illuminated with orange light when the lighting load is off. Actuation of the upper portion of the front surface  108 , i.e., above the portion surrounding the icon  116 , causes the intensity of the lighting load  208  to change. The status indicators  114  behind the status markers  112  are illuminated to display the intensity of the lighting load  208 . For example, if the lighting load  208  is at 50% lighting intensity, the middle status indicator will be illuminated. Preferably, the dimmer  100  does not respond to actuations in a keepout region  118  of the front surface  108 . The keepout region  118  prevents inadvertent actuation of an undesired portion of the front surface  108  during operation of the dimmer  100 . 
         [0050]    The dimmer  100  further includes an airgap switch actuator  119 . Pulling the airgap switch actuator  119  opens a mechanical airgap switch  219  ( FIG. 7 ) inside the dimmer  100  and disconnects the lighting load  208  from a connected AC voltage source  204  ( FIG. 7 ). The airgap switch actuator  119  extends only sufficiently above the front surface  103  of the faceplate  102  to be gripped by a fingernail of a user. The electronic circuitry of the dimmer  100  (to be described in greater detail below) is mounted on a printed circuit board (PCB) (not shown). The PCB is housed in an enclosure (not shown), i.e., an enclosed volume, which is attached to the yoke of the dimmer  100 . 
         [0051]      FIG. 5A  is a partial assembled sectional view and  FIG. 5B  is a partial exploded sectional view of the bezel  108  and the touch sensitive device  110  of the dimmer  100  according to the present invention. The touch sensitive device  110  comprises, for example, a resistive divider, and operates in a similar fashion as the touch-operated device  30  of the prior art touch dimmer  40 . The touch sensitive device  110  includes a conductive element  120  and a resistive element  122  supported by a spacing frame  124 . However, the touch sensitive device  110  may comprise a capacitive touch screen or any other type of touch responsive element. Such touch sensitive devices are often referred to as touch pads or touch screens. 
         [0052]    An elastomer  126  is received by an opening  128  in the rear surface of the bezel  106 . The elastomer  126  is positioned between the bezel  106  and the touch sensitive device  110 , such that a press on the front surface  108  of the bezel is transmitted to the conductive element  120  of the touch sensitive device  110 . Preferably, the elastomer  126  is made of rubber and is 0.040″ thick. The elastomer  126  preferably has a durometer of 40 A, but may have a durometer in the range of 20 A to 80 A. The conductive element  120  and the resistive element  122  of the touch sensitive device  110  and the elastomer  126  are preferably manufactured from a transparent material such that the light from the plurality of status indicators  114  inside the dimmer  100  are operable to shine through the touch sensitive device  110  and the elastomer  126  to front surface  108  of the bezel  106 . 
         [0053]    The position and size of the touch sensitive device  110  is demonstrated by the dotted line in  FIG. 4B . The touch sensitive device  110  has a length L 1  and a width W 1  that is larger than a length L 2  and a width W 2  of the front surface  108  of the bezel  106 . Accordingly, a first area A 1  of the surface of touch sensitive device  110  (i.e., A 1 =L 1 ·W 1 ) is greater than a second area A 2  of the front surface  108  of the bezel  106  (i.e., A 2 =L 2 ·W 2 ). An orthogonal projection of the second area A 2  onto the first area A 1  is encompassed by the first area A 1 , such that a point actuation at any point on the front surface  108  of the bezel  106  is transmitted to the conductive element  120  of the touch sensitive device  110 . As shown in  FIGS. 4A and 4B , the length L 2  of the front surface  108  of the bezel  106  is approximately four (4) times greater than the width W 2 . Preferably, the length L 2  of the front surface  108  of the bezel  106  is four (4) to six (6) times greater than the width W 2 . Alternatively, the front surface  108  of the bezel  106  may be provided in an opening of a decorator-style faceplate 
         [0054]      FIG. 6  shows the force profiles of the components of the dimmer  100  shown in  FIGS. 5A and 5B  and a cumulative force profile for the touch sensitive device  110  of the dimmer  100 . Each of the force profiles shows the force required to actuate the touch sensitive device  110  with respect to the position of the point actuation. The force profile represents the amount of force required to displace the element by a given amount. While the force profiles in  FIG. 6  are shown with respect to the widths of the components of the dimmer  100 , a similar force profile is also provided along the length of the components. 
         [0055]      FIG. 6(   a ) shows a force profile of the bezel  106 . The bezel  106  has substantially thin sidewalls  129 , e.g., 0.010″ thick, such that the bezel  106  exhibits a substantially flat force profile.  FIG. 6(   b ) shows a force profile of the touch sensitive device  110 . The force required to actuate the touch sensitive device  110  increases near the edges because of the spacing frames  124 .  FIG. 6(   c ) shows a force profile of the elastomer  126 . The force profile of the elastomer  126  is substantially flat, i.e., a force at any point on the front surface of the elastomer  126  will result in a substantially equal force at the corresponding point on the rear surface. 
         [0056]      FIG. 6(   d ) is a total force profile of the touch dimmer  100 . The individual force profiles shown in  FIGS. 6(   a )- 6 ( c ) are additive to create the total force profile. The total force profile is substantially flat across the second area A 2  of the front surface  108  of the bezel  106 . This means that a substantially equal minimum actuation force f MIN  is required to actuate the touch sensitive device  110  at all points of the front surface  108  of the bezel  106 , even around the edges. Accordingly, the dimmer  100  of the present invention provides a maximum operational area in an opening of a faceplate, i.e., substantially all of the second area A 2  of the front surface  108  of the bezel  106 , which is an improvement over the prior art touch dimmers. The minimum actuation force f MIN  is substantially equal at all points on the front surface  108  of the bezel  106 . For example, the minimum actuation force f MIN  may be 20 grams. 
         [0057]      FIG. 7  is a simplified block diagram of the touch dimmer  100  according to the present invention. The dimmer  100  has a hot terminal  202  connected to an AC voltage source  204  and a dimmed hot terminal  206  connected to a lighting load  208 . The dimmer  100  employs a bidirectional semiconductor switch  210  coupled between the hot terminal  202  and the dimmed hot terminal  206 , to control the current through, and thus the intensity of, the lighting load  208 . The semiconductor switch  210  has a control input (or gate), which is connected to a gate drive circuit  212 . The input to the gate renders the semiconductor switch  210  selectively conductive or non-conductive, which in turn controls the power supplied to the lighting load  208 . The gate drive circuit  212  provides a control input to the semiconductor switch  210  in response to a control signal from a controller  214 . The controller  214  may be any suitable controller, such as a microcontroller, a microprocessor, a programmable logic device (PLD), or an application specific integrated circuit (ASIC). 
         [0058]    A zero-crossing detect circuit  216  determines the zero-crossing points of the AC source voltage from the AC power supply  204 . A zero-crossing is defined as the time at which the AC supply voltage transitions from positive to negative polarity, or from negative to positive polarity, at the beginning of each half-cycle. The zero-crossing information is provided as an input to the controller  214 . The controller  214  generates the gate control signals to operate the semiconductor switch  210  to thus provide voltage from the AC power supply  204  to the lighting load  208  at predetermined times relative to the zero-crossing points of the AC waveform. A power. supply  218  generates a direct-current (DC) voltage V CC , e.g., 5 volts, to power the controller  214  and other low voltage circuitry of the dimmer  100 . 
         [0059]    The touch sensitive device  110  is coupled to the controller  214  through a stabilizing circuit  220  and a usage detection circuit  222 . The stabilizing circuit  220  is operable to stabilize the voltage output of the touch sensitive device  110 . Accordingly, the voltage output of the stabilizing circuit  220  is not dependent on the magnitude of the force of the point actuation on the touch sensitive device  110 , but rather is dependent solely on the position of the point actuation. The usage detection circuit  222  is operable to detect when a user is actuating the front surface  108  of the dimmer  100 . The controller  214  is operable to couple and decouple the stabilizing circuit  220  and the usage detection circuit  222  from the output of the touch sensitive device  110 . The controller is further operable to receive control signals from both the stabilizing circuit  220  and the usage detection circuit  222 . Preferably, the stabilizing circuit  220  has a slow response time, while the usage detection circuit  222  has a fast response time. Thus, the controller  214  is operable to control the semiconductor switch  210  in response to the control signal provided by the stabilizing circuit  220  when the usage detection circuit  222  has detected an actuation of the touch sensitive device  110 . 
         [0060]    The controller  214  is operable to drive the plurality of status indicators  114 , e.g., light-emitting diodes (LEDs), which are located behind the markers  112  on the front surface  108  of the dimmer  100 . The status indicators  114  also comprise the blue status indicator and the orange status indicator that are located immediately behind the icon  116 . The blue status indicator and the orange status indicator may be implemented as separate blue and orange LEDs, respectively, or as a single bi-colored LED. 
         [0061]    The dimmer  100  further comprises an audible sound generator  224  coupled to the controller  214 , such that the controller is operable to cause the sound generator to produce an audible sound in response to an actuation of the touch sensitive device  110 . A memory  225  is coupled to the controller  214  and is operable to store control information of the dimmer  100 . 
         [0062]      FIG. 8  is a simplified schematic diagram of the circuitry for the touch sensitive device  110  and the controller  214 , i.e., the stabilizing circuit  220  and the usage detection circuit  222 , according to a first embodiment of the present invention. The resistive element  122  of the touch sensitive device  110  is coupled between the DC voltage V CC  of the power supply  218  and circuit common, such that the DC voltage V CC  provides a biasing voltage to the touch sensitive device. For example, the resistive element  122  may have a resistance R E  of 7.6 kΩ. The position of contact between the conductive element  120  and the resistive element  122  of the touch sensitive device  110  is determined by the position of a point actuation on the front surface  108  of the bezel  106  of the dimmer  100 . The conductive element  120  is coupled to both the stabilizing circuit  220  and the usage detection circuit  222 . As shown in  FIG. 7 , the touch sensitive device  110  of the dimmer  100  of the first embodiment is a three-wire device, i.e., the touch sensitive device has three connections or electrodes. The touch sensitive device provides one output that is representative of the position of the point actuation along a Y-axis, i.e., a longitudinal axis of the dimmer  100  as shown in  FIG. 4B . 
         [0063]    The stabilizing circuit  220  comprises a whacking-grade capacitor C 230  (that is, a capacitor having a large value of capacitance) and a first switch  232 . The controller  214  is operable to control the first switch  232  between a conductive state and a non-conductive state. When the first switch  232  is conductive, the capacitor C 230  is coupled to the output of the touch sensitive device  110 , such that the output voltage is filtered by the capacitor C 230 . When a touch is present, the voltage on the capacitor C 230  will be forced to a steady-state voltage representing the position of the touch on the front surface  108 . When no touch is present, the voltage on the capacitor will remain at a voltage representing the position of the last touch. The touch sensitive device  110  and the capacitor C 230  form a sample-and-hold circuit. The response time of the sample-and-hold circuit is determined by a resistance R D  of the touch sensitive device (i.e., the resistance R E  of the resistive element and a contact resistance R C ) and the capacitance of the capacitor C 230 . During typical actuation, the contact resistance R C  is small compared to the value of R E , such that a first charging time constant τ 1  is approximately equal to R E ·C 230 . This time constant τ 1  is preferably 13 ms, but may be anywhere between 6 ms and 15 ms. 
         [0064]    When a light or transient press is applied to the touch sensitive device  110 , the capacitor C 230  will continue to hold the output at the voltage representing the position of the last touch. During the release of the touch sensitive device  110 , transient events may occur that produce output voltages that represent positions other than the actual touch position. Transient presses that are shorter than the first charging time constant τ 1  will not substantially affect the voltage on the capacitor C 230 , and therefore will not substantially affect the sensing of the position of the last actuation. During a light press, a second charging time constant τ 2  will be substantially longer than during normal presses, i.e., substantially larger than the first time constant τ 1 , due to the higher contact resistance R C . However, the steady-state value of the voltage across the capacitor C 230  will be the same as for a normal press at the same position. Therefore, the output of the stabilizing circuit  220  is representative of only the position of the point of actuation of the touch sensitive device  110 . 
         [0065]    The usage detection circuit  222  comprises a resistor R 234 , a capacitor C 236 , and a second switch  238 , which is controlled by the controller  214 . When the switch  238  is conductive, the parallel combination of the resistor R 234  and the capacitor C 236  is coupled to the output of the touch sensitive device  110 . Preferably, the capacitor C 236  has a substantially small capacitance C 236 , such that the capacitor C 236  charges substantially quickly in response to all point actuations on the front surface  108 . The resistor R 234  allows the capacitor C 236  to discharge quickly when the switch  238  is non-conductive. Therefore, the output of the usage detection circuit  222  is representative of the instantaneous usage of the touch sensitive device  110 . 
         [0066]    The controller  214  controls the switches  232 ,  238  in a complementary manner. When the first switch  232  is conductive, the second switch  238  is non-conductive, and vice versa. The controller  214  controls the second switch  238  to be conductive for a short period of time t USAGE  once every half cycle of the voltage source  204  to determine whether the user is actuating the front surface  108 . Preferably, the short period of time t USAGE  is approximately 100 μsec or 1% of the half-cycle (assuming each half-cycle is 8.33 msec long). For the remainder of the time, the first switch  232  is conductive, such that the capacitor C 230  is operable to charge accordingly. When the first switch  232  is non-conductive and the second switch  238  is conductive, the whacking-grade capacitor C 230  of the stabilizing circuit  220  is unable to discharge at a significant rate, and thus the voltage developed across the capacitor C 230  will not change significantly when the controller  214  is determining whether the touch sensitive device  110  is being actuated through the usage detection circuit  222 . While the stabilizing circuit  220  is shown and described as a hardware circuit in the present application, the controller  214  could alternatively provide the filtering functionality of the stabilizing circuit entirely in software. 
         [0067]      FIG. 9  is a simplified schematic diagram of the audible sound generator  224  of the dimmer  100 . The audible sound generator  224  uses an audio power amplifier integrated circuit (IC)  240 , for example, part number TPA721 manufactured by Texas Instruments, Inc., to generate a sound from a piezoelectric or magnetic speaker  242 . The amplifier IC  240  is coupled to the DC voltage V CC  (pin  6 ) and circuit common (pin  7 ) to power the amplifier IC. A capacitor C 244  (preferably having a capacitance of 0.1 μF) is coupled between the DC voltage V CC  and circuit common to decouple the power supply voltage and to ensure the output total harmonic distortion (THD) is as low as possible. 
         [0068]    The audible sound generator  224  receives a SOUND ENABLE signal  246  from the controller  214 . The SOUND ENABLE signal  246  is provided to an enable pin (i.e., pin  1 ) on the amplifier IC  240 , such that the audible sound generator  224  will be operable to generate the sound when the SOUND ENABLE signal is at a logic high level. 
         [0069]    The audible sound generate 224 further receives a SOUND WAVE signal  248  from the controller  214 . The SOUND WAVE signal  248  is an audio signal that is amplified by the amplifier IC  240  to generate the appropriate sound at the speaker  242 . The SOUND WAVE signal  248  is first filtered by a low-pass filter comprising a resistor R 250  and a capacitor C 252 . Preferably, the resistor R 250  has a resistance of 1 kΩ and the capacitor C 252  has a capacitance of 0.1 nF. The filtered signal is then passed through a capacitor C 254  to produce an input signal V IN . The capacitor C 254  allows the amplifier IC to bias the input signal V IN  to the proper DC level for optimum operation and preferably has a capacitance of 0.1 μF. The input signal V IN  is provided to a negative input (pin  4 ) of the amplifier IC  240  through a input resistor R 0I . A positive input (pin  3 ) of the amplifier IC  240  and with a bypass pin (pin  2 ) are coupled to circuit common through a bypass capacitor C 256  (preferably, having a capacitance of 0.1 μF). 
         [0070]    The output signal V OUT  of the amplifier IC  240  is produced from a positive output (pin  5 ) to a negative output (pin  8 ) and is provided to the speaker  242 . The negative input (pin  4 ) is coupled to the positive output (pin  5 ) through an output resistor R F . The gain of the amplifier IC  240  is set by the input resistor R I  and the feedback resistor R F , i.e., 
         [0000]      Gain=V OUT /V IN =−2·(R F /R I ). 
       Preferably, the input resistor R I  and the output resistor R F  both have resistances of 10 kΩ, such that the gain of the amplifier IC  240  is negative two (−2). 
       [0071]      FIG. 10  is a flowchart of a touch dimmer procedure  300  executed by the controller  214  of the dimmer  100  according to the present invention. Preferably, the touch dimmer procedure  300  is called from the main loop of the software of the controller  214  once every half cycle of the AC voltage source  204 . The touch dimmer procedure  300  selectively executes one of three procedures depending upon the state of the dimmer  100 . If the dimmer  100  is in an “Idle” state (i.e., the user is not actuating the touch sensitive device  110 ) at step  310 , the controller  214  executes an Idle procedure  400 . If the dimmer  100  is in an “ActiveHold” state (i.e., the user is presently actuating the touch sensitive device  110 ) at step  320 , the controller  214  executes an ActiveHold procedure  500 . If the dimmer  100  is in a “Release” state (i.e., the user has recently ceased actuating the touch sensitive device  110 ) at step  330 , the controller  214  executes a Release procedure  600 . 
         [0072]      FIG. 11  is a flowchart of the Idle procedure  400  according to the present invention. The controller  114  uses a “sound flag” and a “sound counter” to determine when to cause the audible sound generator  224  to generate the audible sound. The purpose of the sound flag is to cause the sound to be generated the first time that the controller  214  executes the ActiveHold procedure  500  after being in the Idle state. If the sound flag is set, the controller  214  will cause the sound to be generated. The sound counter is used to ensure that the controller  214  does not cause the audible sound generator  224  to generate the audible sound too often. The sound counter preferably has a maximum sound counter value S MAX , e.g., approximately 425 msec. Accordingly, there is a gap of approximately 425 msec between generations of the audible sound. The sound counter is started during the Release procedure  600  as will be described in greater detail below. Referring to  FIG. 11 , upon entering the Idle state, the controller  214  sets the sound flag at step  404  if the sound flag is not set at step  402 . 
         [0073]    An “LED counter” and an “LED mode” are used by the controller  214  to control the status indicators  114  (i.e., the LEDs) of the dimmer  100 . The controller  214  uses the LED counter to determine when a predetermined time t LED  has expired since the touch sensitive device  110  was actuated. When the predetermined time t LED  has expired, the controller  214  will change the LED mode from “active” to “inactive”. When the LED mode is “active”, the status indicators  114  are controlled such that one or more of the status indicators are illuminated to a bright level. When the predetermined time t LED  expires, the LED mode is changed to “inactive”, i.e., the status indicators  114  are controlled such that one or more of the status indicators are illuminated to a dim level. Referring to  FIG. 11 , if the LED counter is less than a maximum LED counter value L MAX  at step  410 , the LED counter is incremented at step  412  and the process moves on to step  418 . However, if the LED counter is not less than the maximum LED counter value L MAX , the LED counter is cleared at step  414  and the LED mode is set to inactive at step  416 . Since the touch dimmer procedure  300  is executed once every half cycle, the predetermined time t LED  is preferably equal to 
         [0000]      t LED =T HALF ·L MAX , 
         [0000]    where T HALF  is the period of a half cycle. 
         [0074]    Next, the controller  214  reads the output of the usage detection circuit  222  to determine if the touch sensitive device  110  is being actuated. Preferably, the usage detection circuit  222  is monitored once every half cycle of the voltage source  204 . At step  418 , the controller  214  opens switch  232  and closes switch  238  to couple the resistor R 234  and the capacitor C 236  to the output of the touch sensitive device  110 . The controller  214  determines the DC voltage of the output of the usage detection circuit  222  at step  420 , preferably, by using an analog-to-digital converter (ADC). Next, the controller  214  closes switch  232  and opens switch  238  at step  422 . 
         [0075]    At step  424 , if there is activity on the front surface  108  of the dimmer  100 , i.e., if the DC voltage determined at step  420  is above a predetermined minimum voltage threshold, then an “activity counter” is incremented at step  426 . Otherwise, the activity counter is cleared at step  428 . The activity counter is used by the controller  214  to determine if the DC voltage determined at step  420  is the result of a point actuation of the touch sensitive device  110  rather than noise or some other undesired impulse. The use of the activity counter is similar to a software “debouncing” procedure for a mechanical switch, which is well known in the art. If the activity counter is not less than a maximum activity counter value A MAX  at step  430 , then the dimmer state is set to the ActiveHold state at step  432 . Otherwise, the process simply exits at step  434 . 
         [0076]      FIGS. 12A and 12B  are flowcharts of the ActiveHold procedure  500 , which is executed once every half cycle when the touch sensitive device  110  is being actuated, i.e., when the dimmer  100  is in the ActiveHold state. First, a determination is made as to whether the user has stopped using, i.e., released, the touch sensitive device  110 . The controller  214  opens switch  232  and closes switch  238  at step  510 , and reads the output of the usage detection circuit  222  at step  512 . At step  514 , the controller  214  closes switch  232  and opens switch  238 . If there is no activity on the front surface  108  of the dimmer  100  at step  516 , the controller  214  increments an “inactivity counter” at step  518 . The controller  214  uses the inactivity counter to make sure that the user is not actuating the touch sensitive device  110  before entering the Release mode. If the inactivity counter is less than a maximum inactivity counter value I MAX  at step  520 , the process exits at step  538 . Otherwise, the dimmer state is set to the Release state at step  522 , and then the process exits. 
         [0077]    If there is activity on the touch sensitive device  110  at step  516 , the controller  214  reads the output of the stabilizing circuit  220 , which is representative of the position of the point actuation on the front surface  108  of the dimmer  100 . Since the switch  232  is conductive and the switch  238  is non-conductive, the controller  214  determines the DC voltage at the output of the stabilizing circuit  220 , preferably using an ADC, at step  524 . 
         [0078]    Next, the controller  214  uses a buffer to “filter” the output of stabilizing circuit  220 . When a user actuates the touch sensitive device  110 , the capacitor C 230  will charge to approximately the steady-state voltage representing the position of the actuation on the front surface  108  across a period of time determined by the first time constant τ 1  as previously described. Since the voltage across the capacitor C 230 , i.e., the output of the stabilizing circuit  220 , is increasing during this time, the controller  214  delays for a predetermined period of time at step  525 , preferably, for approximately three (3) half cycles. 
         [0079]    When a user&#39;s finger is removed from the front surface  108  of the bezel  106 , subtle changes in the force and position of the point actuation occur, i.e., a “finger roll-off” event occurs. Accordingly, the output signal of the touch sensitive device  110  is no longer representative of the position of the point actuation. To prevent the controller  214  from processing reads during a finger roll-off event, the controller  214  saves the reads in the buffer and processes the reads with a delay, e.g., six half cycles later. Specifically, when the delay is over at step  525 , the controller  214  rotates the new read (i.e., from step  524 ) into the buffer at step  526 . If the buffer has at least six reads at step  528 , the controller  214  averages the reads in the fifth and sixth positions in the buffer at step  530  to produce the touch position data. In this way, when the user stops actuating the touch sensitive device  110 , the controller  214  detects this change at step  516  and sets the dimmer state to the Release state at step  522  before the controller processes the reads saved in the buffer near the transition time of the touch sensitive device. 
         [0080]    At step  532 , the controller  114  determines if the touch position data from step  530  is in the keepout region  118  (as shown in  FIG. 4B ). If the touch position data is in the keepout region  118 , the ActiveHold procedure  500  simply exits at step  538 . Otherwise, a determination is made at step  534  as to whether the sound should be generated. Specifically, if the sound flag is set and if the sound counter has reached a maximum sound counter value S MAX , the controller  214  drives the SOUND ENABLE signal  246  high and provides the SOUND WAVE signal  248  to the audible sound generator  224  to generate the sound at step  535 . Further, the sound flag is cleared at step  536  such that the sound will not be generated as long as the dimmer  100  remains in the ActiveHold state. 
         [0081]    If the touch position data is in the toggle area, i.e., the lower portion of the front surface  108  of the bezel  106  surrounding the icon  116  (as shown in  FIG. 4A ), at step  540 , the controller  214  processes the actuation of the touch sensitive device  110  as a toggle. If the lighting load  208  is presently off at step  542 , the controller  214  turns the lighting load on. Specifically, the controller  214  illuminates the icon  116  with the blue status indicator at step  544  and dims the lighting load  208  up to the preset level, i.e., the desired lighting intensity of the lighting load, at step  546 . If the lighting load is presently on at step  542 , the controller  214  turns on the orange status indicator behind the icon  116  at step  548  and fades the lighting load  208  to off at step  550 . 
         [0082]    If the touch position data is not in the toggle area at step  540 , the controller  214  scales the touch position data at step  552 . The output of the stabilizing circuit  220  is a DC voltage between a maximum value, i.e., substantially the DC voltage V CC , and a minimum value, which corresponds to the DC voltage providing by the touch sensitive device  110  when a user is actuating the lower end of the upper portion of the front surface  108  of the bezel  106 . The controller  214  scales this DC voltage to be a value between off (i.e., 1%) and full intensity (i.e., 100%) of the lighting load  208 . At step  554 , the controller  214  dims the lighting load  208  to the scaled level produced in step  552 . 
         [0083]    Next, the controller  214  changes the status indicators  114  located behind the markers  112  on the front surface  108  of the bezel  106 . As a user actuates the touch sensitive device  110  to change intensity of the lighting load  208 , the controller  214  decides whether to change the status indicator  114  that is presently illuminated. Since there are seven (7) status indicators to indicate an intensity between 1% and 100%, the controller  214  may illuminate the first status indicator, i.e., the lowest status indicator, to represent an intensity between 1% and 14%, the second status indicator to represent an intensity between 15% and 28%, and so on. The seventh status indicator, i.e., the highest status indicator, may be illuminated to represent an intensity between 85% and 100%. Preferably, the controller  214  uses hysteresis to control the status indicators  114  such that if the user actuates the front surface  108  at a boundary between two of the regions of intensities described above, consecutive status indicators do not toggle back and forth. 
         [0084]    Referring to  FIG. 12B , a determination is made as to whether a change is needed as to which status indicator is illuminated at step  556 . If the present LED (in result to the touch position data from step  530 ) is the same as the previous LED, then no change in the LED is required. The present LED is set the same as the previous LED at step  558 , a hysteresis counter is cleared at step  560 , and the process exits at step  570 . 
         [0085]    If the present LED is not the same as the previous LED at step  556 , the controller  214  determines if the LED should be changed. Specifically, at step  562 , the controller  214  determines if present LED would change if the light level changed by 2% from the light level indicated by the touch position data. If not, the hysteresis counter is cleared at step  560  and the process exits at step  570 . Otherwise, the hysteresis counter is incremented at step  564 . If the hysteresis counter is less than a maximum hysteresis counter value H MAX  at step  566 , the process exits at step  570 . Otherwise, the LEDs are changed accordingly based on the touch position data at step  568 . 
         [0086]      FIG. 13  is a flowchart of the Release procedure  600 , which is executed after the controller  214  sets the dimmer state to the Release state at step  522  of the ActiveHold procedure  500 . First, a save flag is set at step  610 . Next, the sound counter is reset at step  612  to ensure that the sound will not be generated again, e.g., for preferably 18 half cycles. At step  618 , a determination is made as to whether the dimmer  100  is presently executed a fade-to-off. If not, the present level is saved as the preset level in the memory  225  at step  620 . Otherwise, the desired lighting intensity is set to off at step  622 , the long fade countdown in started at step  624 , and the preset level is saved as off in the memory  225 . 
         [0087]      FIG. 14A  and  FIG. 14B  are simplified schematic diagrams of the circuitry for a four-wire touch sensitive device  710  and a controller  714  according to a second embodiment of the present invention. The four-wire touch sensitive device  710  has four connections, i.e., electrodes, and provides two outputs: a first output representative of the position of a point actuation along the Y-axis, i.e., the longitudinal axis of the dimmer  100  a shown in  FIG. 4B , and a second output representative of the position of the point actuation along the X-axis, i.e., an axis perpendicular to the longitudinal axis. The four-wire touch sensitive device  710  provides the outputs depending on how the DC voltage V CC  is connected to the touch sensitive device. A stabilizing circuit  720  is operatively coupled to the first output and a usage detection circuit  722  is operatively coupled to the second output. 
         [0088]    The controller  714  controls three switches  760 ,  762 ,  764  to connect the touch sensitive device  710  to the DC voltage V CC  accordingly. When the switches  760 ,  762 ,  764  are connected in position A as shown in  FIG. 14A , the DC voltage V CC  is coupled across the Y-axis resistor, and the X-axis resistor provides the output to the stabilizing circuit  720 . When the switches  760 ,  762 ,  764  are connected in position B as shown in  FIG. 14B , the DC voltage V CC  is coupled across the X-axis resistor, and the Y-axis resistor provides the output to the usage detection circuit  722 . Since the controller  714  provides one output signal to control whether the stabilizing circuit  720  or the usage detection circuit  722  is coupled to the touch sensitive device  110 , the software executed by the controller  714  is the same as the software executed by the controller  214  shown in  FIGS. 10-13 . 
         [0089]      FIG. 15A  is a simplified schematic diagram of the circuitry for the four-wire touch sensitive device  710  and a controller  814  according to a third embodiment of the present invention. The controller  814  is operable to read the position of a point actuation on the four-wire touch sensitive device  710  along both the Y-axis and the X-axis. When determining the position along the Y-axis, the controller  814  operates the same as the controller  714  shown in  FIGS. 14A and 14B  by controlling the switches  760 ,  762 ,  764  as described above. 
         [0090]    An additional stabilizing circuit  870  is provided for determining the position of the point actuation along the X-axis. The additional stabilizing circuit  870  comprises a whacking-grade capacitor C 872 . The controller  814  controls a switch  874  to selectively switch the output of the X-axis between the usage detection circuit  722  and the additional stabilizing circuit  870 . The controller  814  controls the switch  874  in a similar fashion to how the controller  214  controls the switches  232 ,  238  (as shown in  FIG. 8 ). 
         [0091]      FIG. 15B  is a simplified block diagram of a dimmer  1000  according to a fourth embodiment of the present invention.  FIG. 15C  is a simplified schematic diagram of the circuitry for the three-wire touch sensitive device  110  and a controller  1014  of the dimmer  1000  according to the fourth embodiment. The dimmer  1000  comprises only a stabilizing circuit  1020  and does not comprise a usage detection circuit. The stabilizing circuit  1020  only comprises a whacking-grade capacitor C 1030 . Accordingly, the controller  1014  is not operable to control the stabilizing circuit  1020  and is responsive to the touch sensitive device  100  through only the stabilizing circuit. 
         [0092]      FIGS. 16A and 16B  are a perspective view and a front view, respectively, of a touch dimmer  900  according to a fifth embodiment of the present invention.  FIG. 17A  is a bottom cross-sectional view and  FIG. 17B  is an enlarged partial bottom cross-sectional view of the dimmer  900 .  FIG. 18A  is a left side cross-sectional view and  FIG. 18B  is an enlarged partial left side cross-sectional view of the dimmer  900 . 
         [0093]    The touch dimmer  900  includes a thin touch sensitive actuator  910  comprising an actuation member  912  extending through a bezel  914 . The dimmer  900  further comprises a faceplate  916 , which has a non-standard opening  918  and mounts to an adapter  920 . The bezel  914  is housed behind the faceplate  916  and extends through the opening  918 . The adapter  920  connects to a yoke  922 , which is adapted to mount the dimmer  900  to a standard electrical wallbox. A main printed circuit board (PCB)  924  is mounted inside an enclosure  926  and includes the some of the electrical circuitry of the dimmer  200 , e.g., the semiconductor switch  210 , the gate drive circuit  212 , the controller  214 , the zero-crossing detect circuit  216 , the power supply  218 , the stabilizing circuit  220 , the usage detection circuit  222 , the audible sound generator  224 , and the memory  225 , of the dimmer  200 . The thin touch sensitive actuator  910  preferably extends beyond the faceplate by 1/16″, i.e., has a height of 1/16″, but may have a height in the range of 1/32″ to 3/32″. Preferably, the touch sensitive actuator  910  has a length of 3⅝″ and a width of 3/16″. However, the length and the width of the touch sensitive actuator  910  may be in the ranges of 2⅝″-4″ and ⅛″-¼″, respectively. 
         [0094]    The touch sensitive actuator  910  operates to contact a touch sensitive device  930  inside the touch dimmer  900 . The touch sensitive device  930  is contained by a base  932 . The actuation member  912  includes a plurality of long posts  934 , which contact the front surface of the touch sensitive device  930  and are arranged in a linear array along the length of the actuation member. The posts  934  act as force concentrators to concentrate the force from an actuation of the actuation member  912  to the touch sensitive device  930 . 
         [0095]    A plurality of status indicators  936  are arranged in a linear array behind the actuation member  912 . The status indicators are mounted on a display PCB  938 , i.e., a status indicator support board, which is mounted between the touch sensitive device  930  and the bezel  914 .  FIG. 19  is a perspective view of the display PCB  938 . The display PCB  938  includes a plurality of holes  939 , which the long posts  934  extend through to contact the touch sensitive device  930 . The actuation member  912  is preferably constructed from a translucent material such that the light of the status indicators  936  is transmitted to the surface of the actuation member. A plurality of short posts  940  are provided in the actuation member  912  directly above the status indicators  936  to operate as light pipes for the linear array of status indicators. The display PCB  938  comprises a tab  952  having a connector  954  on the bottom side for connecting the display PCB  938  to the main PCB  924 . 
         [0096]    The actuation member  912  comprises a notch  942 , which separates a lower portion  944  and an upper portion  946  of the actuation member. Upon actuation of the lower portion  944  of the actuation member  912 , the dimmer  900  causes the connected lighting load to toggle from on to off (and vice versa). Preferably, a blue status indicator  948  and an orange status indicator  950  are located behind the lower portion  944 , such that the lower portion is illuminated with blue light when the lighting load is on and illuminated with orange light with the lighting load is off. Actuation of the upper portion  946  of the actuation member  912 , i.e., above the notch  942 , causes the intensity of the lighting load to change to a level responsive to the position of the actuation on the actuation member  912 . The status indicators  936  behind the status markers  112  are illuminated to display the intensity of the lighting load as with the previously-discussed touch dimmer  100 . 
         [0097]      FIG. 20  is an enlarged partial bottom cross-sectional view of a thin touch sensitive actuator  960  according to a sixth embodiment of the present invention. The touch sensitive actuator  960  comprises an actuation member  962  having two posts  964  for actuating the touch sensitive device  930 . A plurality of status indicators  966  are mounted on a flexible display PCB  968 , i.e., a flexible status indicator support board, which the posts  964  of the actuation member  962  are operable to actuate the touch sensitive device  930  through. The status indicators  966  are preferably blue LEDs and are arranged along the length of the actuation member  962 . Preferably, the actuation member  962  is constructed from a translucent material such that the light of the status indicators  966  is transmitted to the surface of the actuation member. 
         [0098]    Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.