Abstract:
A control system includes an electrical load control device responsive to radiant energy and a transmitter. The transmitter includes two sets of radiant energy generators connected to an electrical circuit such that polarity of the sets is reversed. A transmissive enclosure includes indented portions defining deflectors oriented obliquely with respect to a generator support surface. The transmitter is secured to a bracket for attachment to a backcover of the load control device. The control system may also include a master control generating an electrical control signal in response to an actuator or in response to a radiant energy signal. The control system is capable of limiting the master control to generate a signal only in response to the actuator. A power supply for the transmitter includes a filter network having a filter capacitor and resistor in series with a power supply capacitor and a diode in parallel with the resistor.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a continuation of application Ser. No. 10/210,679, filed Aug. 1, 2002, which claimed priority from U.S. Provisional Application Ser. No. 60/309,929, filed Aug. 3, 2001. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to dimmer control systems and more particularly to dimmer control systems in which a master control communicates with multiple dimmers.  
       BACKGROUND OF THE INVENTION  
       [0003]     Dimmers have become increasingly popular for controlling light intensity. Dimmers typically employ solid-state devices such as triacs, silicon-controlled rectifiers, or field-effect transistors for varying the phase angle of an applied a.c. sinusoidal voltage. Known dimmers are responsive to command signals directed at the dimmer in the form of radiant energy, typically in the infrared range. Infrared transmissive windows or sections allow the command signal to reach an IR receiver housed within the dimmer.  
         [0004]     IR responsive dimmers allow for dimmer control systems in which an IR command signal can be “blasted” from one source of IR radiation for receipt by multiple dimmers. An example of a dimmer control system that uses infrared radiation to communicate command signals from one source of IR to multiple dimmers is the SPACER SYSTEM™ sold by Lutron Electronics Co., Inc. of Coopersburg, Pa. The SPACER SYSTEM™ utilizes a master control having an optically clear back cover that allows command signals from a source of IR radiation located within the master control to be “blasted” outwardly from the master control into control having an optically clear back cover that allows command signals from a source of IR radiation located within the master control to be “blasted” outwardly from the master control into the wallbox that houses the master control. The system also includes multiple dimmers housed in the same wallbox. Each of the dimmers includes an optically clear back cover and an internal IR receiver. The IR receiver of each dimmer receives infrared command signals that are blasted into the wallbox from the master control. The system is also disclosed in U.S. patent application Ser. No. 09/220,632, issued as U.S. Pat. No. 6,380,696, assigned to Lutron Electronics Co., Inc., the Assignee of this application.  
       SUMMARY OF THE INVENTION  
       [0005]     According to one aspect of the invention, there is provided a control system including at least one electrical load control device responsive to command signals in the form of radiant energy. The control system further includes a transmitter for producing command signals in the form of radiant energy for receipt by the at least one electrical load control device. The transmitter includes a pair of conductive terminals for receiving command signals in the form of electrical signals. The transmitter further includes two sets radiant energy generators each having a polarity for connection to an electrical circuit. The radiant energy generators are operably connected in an electrical circuit containing the conductive terminals such that the polarity of the generators of one of the sets is reversed with respect to the polarity of the generators of the other set. The radiant energy generators are further connected to the electrical circuit such that the sets are connected in parallel with one another.  
         [0006]     According to another aspect of the invention, there is provided a control system including at least one electrical control device responsive to command signals in the form of radiant energy and a transmitter producing command signals in the form of radiant energy. The control system further includes a radiant energy deflector located between the transmitter and the at least one electrical load device for deflecting at least a portion of the radiant energy from the transmitter in a desired direction.  
         [0007]     According to another aspect of the invention there is provided a control system including at least one electrical load control device responsive to command signals in the form of radiant energy and a transmitter, the transmitter capable of transmitting a command signal in the form of radiant energy in response to receipt of an electrical signal. The transmitter is connected to a master control by conductive wire, the master control producing electrical command signals for conveyance to the transmitter via the conductive wire. The master control includes at least one actuator accessible by a user of the master control for generation of an electrical command signal by the master control and a radiant energy receiver. The master control is capable of generating an electrical command signal in response to receipt of a radiant energy signal for relaying the signal to the transmitter. The control system is capable of preventing the master control from generating an electrical signal in response to receipt of a radiant energy signal such that the master control can only generate electrical signals in response to use of the at least one actuator.  
         [0008]     According to another aspect of the invention there is provided a control system including a transmitter having at least one radiant energy generator for producing command signals in the form of radiant energy and at least one electrical load control device responsive to command signals in the form of radiant energy. The electrical load device is transmissive to the radiant energy of the transmitter and includes a cover portion. The control system further includes a bracket supporting the transmitter for attachment of the transmitter to the electrical load control device. The bracket engages the cover portion of the electrical load control device to position the at least one radiant energy generator with respect to the electrical load device.  
         [0009]     According to another aspect of the invention there is provided a power supply for an infrared transmitter having at least one LED driver. The power supply includes a power supply capacitor and a filter network, the filter network including a filter capacitor and a resistor connected in series with the power supply capacitor. The power supply further includes a diode connected in parallel with the resistor of the filter network to provide isolation between the filter capacitor and the power supply capacitor. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a schematic illustration of a dimmer control system according to the present invention;  
         [0011]      FIG. 2  is a perspective view of a remote infrared transmitter according to the present invention mounted to an attachment bracket;  
         [0012]      FIG. 3  is an exploded perspective view of the remote infrared transmitter and attachment bracket of  FIG. 2 ;  
         [0013]      FIG. 4  is a perspective view of the remote infrared transmitter and attachment bracket of  FIG. 2  adjacent a dimmer back cover;  
         [0014]      FIG. 5  is a perspective view of the remote infrared transmitter and attachment bracket of  FIG. 2  engaged to a dimmer back cover;  
         [0015]      FIG. 6A  is a perspective view of the enclosure of the remote infrared transmitter of  FIG. 2 ;  
         [0016]      FIG. 6B  is a bottom plan view of the enclosure of  FIG. 6A ;  
         [0017]      FIG. 6C  is side elevational view of the enclosure of  FIG. 6A ;  
         [0018]      FIG. 6D  is a sectional view of the enclosure of  FIG. 6B  taken along the lines A-A;  
         [0019]      FIG. 6E  is a sectional view of the enclosure of  FIG. 6C  taken along the lines B-B;  
         [0020]      FIG. 6F  is an end view of the enclosure of  FIG. 6A ;  
         [0021]      FIG. 7  is a top view of the enclosure and LEDs of a remote infrared transmitter according to the present invention;  
         [0022]      FIG. 8  is a side view of the enclosure and LEDs of  FIG. 7 ;  
         [0023]      FIG. 9  is side view of one of the LEDs of  FIGS. 7 and 8  having notations thereon;  
         [0024]      FIG. 10  is an electrical schematic for a remote infrared transmitter according to the present invention;  
         [0025]      FIG. 11  is an electrical schematic of a power supply circuit for a remote infrared transmitter according to the present invention;  
         [0026]      FIG. 12  is a simplified schematic representation of the circuit of  FIG. 11 ;  
         [0027]      FIG. 13  is a graphical illustration of power supply waveforms;  
         [0028]      FIG. 14  is a schematic illustration of a dimmer control system according to the present invention set for operation in a first mode; and  
         [0029]      FIG. 15  is a schematic illustration of the dimmer control system of  FIG. 14  set for operation in a second mode. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]     Referring to the drawings, where like numerals identify like elements, there is shown a dimmer control system  10  according to the present invention. The control system  10  includes a master control  12  shown schematically in  FIG. 1  located within a first wallbox  14 . Hot and neutral wires connect the master control  12 , in the well-known manner, to a power supply, such as the power distribution panel of a dwelling, for example.  
         [0031]     The control system  10  also includes two sets of dimmers  16  located in separate second and third wallboxes  18  and  20 , respectively. As shown in  FIG. 1 , the first wallbox  14  in which the master control  12  is located is separate from the second and third wallboxes  18  and  20  in which the dimmers  16  are located. Each of the dimmers  16  is capable of controlling the current supplied to an electrical load, such as a light, for example.  
         [0032]     An example of a suitable master control  12  and suitable dimmers  16  for use in the control system of the present invention is described in U.S. patent application Ser. No. 09/220,632, issued as U.S. Pat. No. 6,380,696, which is hereby incorporated by reference. Features and operation of the dimmers are also described in U.S. Pat. Nos. 5,248,919 and 5,909,087, which are also hereby incorporated by reference. Each dimmer  16  includes a large actuator for a single non-latching switch. Within the border of the large actuator is an infrared receiving window  24  for receipt of infrared signals by an infrared receiver located behind window  24 . Such signals may come from a hand held remote controller, for example. The dimmers  16  further include a user adjustable intensity actuator  26  for raising and lowering the light level of an attached load. An LED array  28  displays information including information about the light level of the attached load. The dimmers are capable of memory storage of preset light levels, associated with preferred lighting “scenes” for example. The dimmers are responsive to infrared command signals received by the IR receiver, to set the dimmers to the preset light levels stored by the dimmers for example.  
         [0033]     The master control  12  includes an “ON” actuator  30 , an “OFF” actuator  32 , four preset actuators  34 , an intensity actuator  36 , LED indicators  38  and an IR receiving window  40  in one of the preset actuators  34 . The master control includes a microprocessor (not shown) that performs various functions such as output of control signals to the dimmers  16  including setting of the dimmers to the preset light level stored in memory by the dimmers.  
         [0034]     The dimmer control system  10  includes a pair of electrical conductors, referred to herein as traveler wires,  42  and  44  for carrying dimmer control signals from the master control  12  in the first wallbox  14  to the dimmers  16  located in the second and third wallboxes  18  and  20  as will be described in greater detail below. The traveler wires are preferably No. 14 AWG at a minimum. As seen in  FIG. 1 , each of the traveler wires  42 ,  44  splits into separate traveler wires  42 A,  42 B and  44 A,  44 B, respectively, for carrying control signals from the master control  12  to the separate sets of dimmers  16  in the second and third wallboxes  18 ,  20 .  
         [0035]     The control system  10  includes an infrared (IR) transmitter  46  for each of the wallboxes  18 ,  20  of the dimmers  16 . Each of the IR transmitters  46  is connected to one pair of the traveler wires, either  42 A,  44 A or  42 B,  44 B, for receipt of dimmer control signals from the master control. Each of the IR transmitters  46 , schematically shown in  FIG. 1 , is removably secured to the back cover of a dimmer  16  for locating the IR transmitter in the dimmer wallbox behind one of the dimmers, as will be described further hereinafter.  
         [0036]     Referring to  FIGS. 2-9 , the construction and operation of the IR transmitter  46  associated with wallbox  18  is shown in greater detail. The IR transmitter  46  for wallbox  20  is similar in construction and operation to the IR transmitter shown in  FIGS. 2-9 . The transmitter  46  includes an optically clear enclosure  48  that is transmissive to both visible and IR light. A suitable material for forming the optically clear enclosure  48  is Lexan® resin number 241R available from General Electric.  
         [0037]     The IR transmitter  46  includes conductive terminals  50  each having a pair of upstanding legs  52  for receipt of conductive leads  54  of the traveler wires  42 A and  44 A that extend into the enclosure  48 . The terminals  50  are supported on an upper surface of a printed wire board  56 . The transmitter  46  includes four LEDs  58 A- 58 D that provide the source of infrared radiation for blasting the IR command signals to the IR receivers through the IR transmissive enclosure  48 . As seen in  FIGS. 2 and 3 , the LEDs  58 A- 58 D are arranged such that LEDs  58 A and  58 B are located at an opposite end of the elongated enclosure  48  from LEDs  58 C and  58 D. Electrically, the LEDs are connected in anti-parallel fashion as shown in  FIG. 10 . This arrangement provides for a polarity insensitive wiring, to be described in greater detail hereinafter, in which one of the LEDs  58 A- 58 D at each of the opposite ends of the elongated enclosure will blast IR signals regardless of which of the terminals  50  is used to connect the respective traveler wires  42 A,  44 A.  
         [0038]     The IR transmitter  46  also includes an attachment bracket  60 , preferably made of an electrically conductive material such as stainless steel, for securing the IR transmitter  46  to one of the dimmers  16 . The attachment bracket secures the transmitter  46  to the dimmer  16  such that the transmitter is positioned adjacent to a back cover  62  of the dimmer  16 . The back cover  62  is made from an optically clear material, such as the Lexan® resin material from which the transmitter enclosure  48  is made, to allow for passage of the IR signal blasted from transmitter  46  to an IR receiver enclosed by the back cover  62 . It is preferable that the transmitter  46  be attached to a centrally located dimmer  16  of a dimmer set to facilitate transmission of the IR signal to each of the dimmers  16  of the set.  
         [0039]     The attachment bracket  60  includes a generally planar support portion  64  for supporting the printed wire board  56  and enclosure  48 . The support portion includes slots  66  for receipt of tabs  68  of enclosure  48  for removably attaching of enclosure  48  to the attachment bracket  60 . The attachment bracket  60  further includes positioning clips  70  extending generally perpendicularly to the plane of the support portion  64 . As best seen in  FIGS. 4 and 5 , the clips  70  are received by sidewalls  72  of the dimmer back cover  62 . The primary function of the positioning clips is to center the transmitter  46  with respect to the dimmer  16  as seen in  FIG. 5 .  
         [0040]     The attachment bracket also includes mounting clips  74  that provide the primary means of attaching the transmitter  46  to the dimmer  16 . The attachment bracket  60  further includes a second set of clips  74  having a U-shaped cross section forming a channel  76 . The clips  74  extend from an extension  78  of the support portion  64  oppositely from clips  70 . As best seen in  FIG. 5 , the clips  74  engage a yoke  80  of dimmer  16  such that an end portion  82  of the yoke is received in the channels  76  of clips  74 . As seen in  FIG. 5 , the attachment and positioning of the transmitter  46  provided by clips  70  and  74  of attachment bracket  60  orients the enclosure  48  adjacent the back cover  62 . This construction facilitates blasting of IR signals into the dimmer  16  through the back cover.  
         [0041]     The use of an electrically conductive material for the attachment bracket  60  provides for use of the attachment bracket to ground the IR transmitter to the wallbox through the yoke  80 . This construction eliminates the need for a separate grounding wire to make the grounding connection within the wallbox.  
         [0042]     Referring to FIGS.  6 A-F the construction of the enclosure  48  is shown in greater detail. As best seen in  FIGS. 6A and 6D , the enclosure includes a pair of rounded notches  84  in one side to provide for passage of the traveler wires  42 A,  44 A through the enclosure  48 . The location of the notches along the lower edge of the enclosure  48  provides for securement of the enclosure to the attachment bracket  60  with the conductive leads  54  engaging the legs of the terminals  50 . The enclosure  48  also includes posts  86  that, as best seen in  FIG. 6D , extend downwardly from the enclosure. The posts engage locating holes  87  that are provided in the printed wire board  56  (best seen in  FIG. 3 ).  
         [0043]     The posts  86  serve two primary functions. They serve to temporarily locate the printed wire board  56  within the enclosure  48  while the enclosure  48  is being snapped into position on the attachment bracket  60 . The posts  86  also serve to prevent the LEDs  58 A- 58 D mounted on the printed wire board  56  from striking the enclosure  48 . As seen in  FIG. 6D , the enclosure includes shoulder portions surrounding each of the posts  86  that serve to maintain separation between the LEDs  58 A- 58 D and the upper portion of enclosure  48 .  
         [0044]     The enclosure  48  further includes a central rib  89  extending transversely across the enclosure. The central rib  89 , acting in conjunction with the shoulder portions of the posts  86 , serves to pin the printed wire board  56  between the enclosure  48  and the attachment bracket  60  when the tabs  68  engage the slots  66 . This prevents the printed wire board  56  from floating within the enclosure  48 . The central rib  89  also acts in conjunction with the shoulder portions of the posts  86  to prevent the LEDs  58 A- 58 D from striking the enclosure  48 . The transversely extending central rib  89  further serves to bisect the enclosure  48  thereby providing for additional electrical isolation between the leads  54  of traveler wires  42 A,  44 A.  
         [0045]     As best seen in  FIGS. 6A-6D  and in  FIGS. 7 and 8 , the enclosure  48  includes a pair of indented portions  88  extending inwardly from an upper portion  90  of the enclosure. Each of the indented portions includes generally planar first and second legs  92  and  94 , respectively. As best seen in  FIG. 8 , the angle of the first leg  92  with respect to the upper portion  90  is less than the angle of the second leg  94  such that the first leg  92  is longer than the second leg  94 . The indented portions  88  are located on the enclosure  48  such that when the enclosure is secured to the printed wire board  56 , the LEDs  58 A- 58 D are located below the first leg  92 . This is best seen in  FIGS. 7 and 8 .  
         [0046]     The inclusion of the indented portions  88  of enclosure  48  serves to direct the IR radiation blasted from the LEDs  58 A- 58 D. The direction of the IR emitted from the transmitter  46  is further enhanced by the construction of the LEDs  58 A- 58 D. As illustrated in  FIG. 9 , in which LED  58 A is shown, the LEDs are constructed to emit an upwardly directed cone of IR radiation with respect to the plane of the printed wire board  56 , having a half-angle of 30 degrees. As the cone of IR light strikes the first leg  92  of the indented portion  88 , the majority of the IR light, approximately  80  percent, is reflected parallel to the plane of the printed wire board  56  through one of the opposite ends of the elongated enclosure  48 . A minority of the IR light, approximately 20 percent, passes vertically through the first leg  92 . Directing the IR radiation in this manner facilitates blasting the IR signal into outwardly located dimmers  16  when the IR transmitter is secured to a centrally located dimmer of a set of dimmers.  
         [0047]     Turning to  FIG. 10 , a wiring schematic is shown for LEDs  58 A- 58 D. As may be seen, the diodes are arranged in two sets of diodes that are connected in parallel with one another. LEDs  58 A and  58 C form the first set and LEDs  58 B and  58 D form the second set. The LEDs are connected in the electrical circuit such that the polarity of the LEDs of the first set is reversed from the polarity of the second set. This “anti-parallel” connection of the two sets of LEDs ensures that one of the sets will operate to generate infrared signals regardless of which of the terminals  50  the respective traveler wires  42 A and  44 A are connected to. In this manner, the connection of traveler wires is rendered polarity insensitive such that IR signals will be directed out of the opposite ends of the elongated enclosure regardless of the connection chosen.  
         [0048]     Referring to  FIGS. 11-13 , the present invention provides for an improved power supply system for the IR transmitters. As seen in  FIG. 11 , the power supply for the master control system  10  includes a power supply circuit  100  that includes a power supply capacitor  102 . The traveler wires  42 ,  44  that extend from the master control  12  will typically be at 120 volts with respect to ground. As shown in  FIG. 11 , the voltage required to drive the LEDs  58 A- 58 D of transmitter  46  will be provided by a separate 13-volt supply. This 13-volt supply is used to power the IR LEDs  58 A- 58 D, drive a 5-volt regulator  104  and supply current pulses that operate drivers  106  for the LEDs.  
         [0049]     The present invention provides an improved filter  108 , shown enclosed by dotted lines in  FIG. 11 , for running the LED drivers  106 . Referring to  FIG. 12 , a filtering resistor  110  and capacitor  112  are included in the filter  108 . The use of a resistor/capacitor (R-C) network is the conventional manner of running noisy circuitry such as the LED drivers from a main power supply capacitor such as capacitor  102 . However, an R-C network alone would fail to protect the main power supply capacitor against sharp current spikes caused by the operation of the LED drivers. The lack of isolation between the two capacitors provided by an R-C network would result in charge being pulled from the main power supply capacitor as well as the filter capacitor. As a result, the performance of the main power supply could be degraded.  
         [0050]     The improved filter  108  of the present invention includes a diode  114  which serves to limit the amount of current that can be drawn by the LED drivers  106  directly from the main supply capacitor  102 . The diode  114  is placed in parallel with the resistor  110 . The inclusion of the diode has no effect on the filtering performance of the R-C network. Referring to  FIG. 13 , the graphs illustrate the effect that the addition of the diode has on the power supply line. The inclusion of the diode  114  serves to limit the amount of charge that may be drawn from the main supply capacitor  102 . As shown in  FIG. 13 , the inclusion of the diode  114  serves to reduce the voltage spikes that would otherwise appear on the power supply line.  
         [0051]     Referring now to the schematic illustrations of  FIGS. 14 and 15 , the dimmer control system  10  of the present invention provides for toggling of the control system  10  between two modes of operation. Each of the dimmers  16  is capable of receiving IR signals through the IR window  24  from in front of the dimmer. Each of the dimmers  16  is also capable of receiving IR signals through the back cover  26  in the wallbox behind the dimmer. This creates the possibility of “collisions” between IR signals received by the dimmer both from direct reception of an infrared signal through window  24  (from a handheld remote control, for example) as well as from indirect reception of the signal if the same signal is received by the master control  12  and relayed to the dimmers  16  by the IR transmitter  46 .  
         [0052]     Referring to  FIG. 14  there is shown a first mode, or “room” mode of operation. The “room” mode of operation is useful for situations where collisions between a direct IR signal and an indirect relayed IR signal are possible. Such a situation might occur, for example, where the wallboxes containing the master control  12  and the dimmers  16  are located in the same room. In the room mode, the master control  12  is disabled from relaying an IR signal that is received by the master control  12 , from a handheld remote control for example. Although the master control  12  is prevented from relaying a received IR signal, the master control remains enabled to transmit IR signals to the dimmers  16  directly in response to use of the actuators of master control  12  shown in  FIG. 1 .  
         [0053]     Referring to  FIG. 15 , the second or “closet” mode of operation is shown. This mode of operation is useful where the possibility of a collision between a direct IR signal and an indirect retransmitted IR signal is limited. This would occur, for example, where a physical barrier  48  such as a wall, is located between the wallbox of the master control  12  and the wallbox of the dimmers  16 . When set to the “closet” mode, the master control is enabled to send IR command signals to the dimmers  16  through the transmitters  46  either in response to use of the actuators of the master control  12  or in response to an IR signal that is received by the master control.