System for light and appliance remote control

A system for remote control of lights and small appliances utilizing miniature remote control units, and a method for easily and simply setting which remote controls control which item(s). Unlike conventional remote controls which are moved from place to place, these miniature remote controls are so small they may be removably mounted at each location needed, unobtrusively or even hidden. Receivers for the remote signal are described manufactured within a lamp socket assembly, a very short light bulb socket adapter, the light bulb itself, a wallswitch dimmer and an outlet adapter. One remote control can control multiple receivers, or vice versa, or any other combination, without conflict and with the combination set up or changed more intuitively than in completing systems. Appliances may be turned on or off and lights may be dimmed precisely or set flashing in unison to summon help.

TECHNICAL FIELD

This disclosure relates to remote control of lights and appliances by radio frequency (RF) techniques and systems for them comprising many remote controls controlling many items without interference.

BACKGROUND

There are five billion light bulb sockets in the United States. This market has fostered numerous devices and schemes to control lights.

The most common controls are wall switches near entrances to rooms. This location is adequate for on-off switches because one normally uses them entering or leaving the room. The room entrance wall switch location is not always adequate for dimmer switches because the need to change light level usually arises when inside the room, often while sitting or lying down, and not when entering and leaving the room. Hence the concept of a remote control has arisen, analogous to a television remote control or a wall switch on a nightstand. Some remote control devices are little more than novelties, controlling a single device at a fixed frequency and easily interfered with by a second remote control nearby. At the other extreme are elaborate and quite expensive “home automation” systems with remote controls having dozens of buttons and often a small screen for user interface. For example, the remote control allows a user to configure the home automation system to turn on a coffee pot the next morning. A lesser expensive and elaborate system is the remote control sold by Lutron®. This is a single remote controller configured to control a single wallswitch. It has five buttons for ON, OFF, brighter, dimmer, and a preset light level. It is infra-red based and, for added convenience (and/or confusion), it is compatible with some other infra-red remote control systems. The remote control is large enough to fit in the hand of a user, but small enough to be easily misplaced. If the user forgets to take it with him/her, it can end up in some other location where it is no more convenient than the wallswitch it is supposed to replace.

SUMMARY

The system disclosed here focuses on simplicity without sacrificing utility. The user can build as elementary or as extensive and interconnected a system as he/she likes without learning a single code or consulting any manual.

The system is based on a miniature remote controller that is only a little bigger than a postage stamp. In one embodiment, the miniature remote controller has just two buttons. One button points UP and the other points DOWN, which is exactly representative of the functions they invoke on a light or appliance being controlled. Designed to be inexpensive, disposable, and interchangeable, a special miniature mounting system allows them to be securely mounted on almost object and later removed without damage. Most importantly, several miniature remote control devices can be installed in a room, one at a time, until users have access to one at every desired location in the room. Various types of receivers compatible with the miniature remote controls complete the system and can be purchased and put it use, again, one at a time. There is no central station. Five types of receivers are described herein. They are not intended to be limiting and the embodiments presented for each are representative only. The five types are:

(a) A very short light socket adapter that is screwed in between a light bulb and its socket. An example of such an adapter is disclosed in the aforementioned co-pending application.

(b) A light bulb of the Compact Fluorescent Lamp (CFL) or Light Emitting Diode (LED) type with a compatible receiver already inside it.

(c) A lamp socket assembly either manufactured with or retrofitted to a lamp.

(d) An outlet adapter plugged in the wall between an appliance plug and the wall outlet.

(e) A permanently installed wallswitch light dimmer or fan control installed instead of or to replace a conventional wallswitch dimmer or fan control.

The miniature controllers and the receivers each have pre-programmed micro-processors with stored codes and sophisticated algorithms for error and conflict avoidance and correction and for inferring the user's intentions. Complication on the inside begets simplicity on the outside to a user as will be apparent from the following.

DETAILED DESCRIPTION

The following terms are used in the following descriptions and their meanings are designated as follows. “Light bulb adapter” herein refers to a device that is inserted into a light bulb socket and into which a light bulb is inserted in turn. “Outlet adapter” refers to a device plugged into an electrical outlet and into which an appliance is plugged in turn. “Wallswitch dimmer” refers control devices typically mounted near doorways to control one or more light fixtures. They may comprise toggle switches, rocker switches, slider switches, or rotary switches.

The term “shortened adapter” refers to a light bulb adapter that provides a shortened bulb displacement. Bulb displacement is the amount the bottom electrical contact of a light bulb is raised above the bottom electrical contact of the light bulb socket by the adapter.

“Light bulb” includes but is not limited to an incandescent light bulb, a non-dimmable or dimmable compact fluorescent light (CFL), and a non-dimmable or dimmable light emitting diode (LED) bulb.

The term “electronic components” refers to active, passive, or sensor components mounted on a printed circuit board or otherwise. This term also includes antennas and mechanical switches. The term “electronic subsystem” refers to a group of electronic components that perform an electronic function, and may include one or more printed circuit boards or a flex strip with various electronic components soldered or otherwise attached to them. “Electronic subsystems” may include parts that are geometrically separated but electrically connected and function together.

“Transmitter” may refer to the chip or other circuit, e.g., circuit208described herein, directly generating the radio frequency signal, that chip plus supporting components, or to the entire miniature remote controller100, described herein, depending on context. “Receiver” may refer to the chip or other circuit, e.g., circuit166described herein, directly detecting the radio frequency signal, that chip plus supporting components, or to the entire adapter1, referred to herein, depending on context.

Miniature Remote Controller

FIG. 1depicts a user's hand holding a miniature remote controller100according to embodiments described herein. The diagram ofFIG. 1includes a user's hand to indicate its shape and very small size. It is so small and compact that it would be awkward to use in one's hand. By design it discourages hand-held use, and further discourages frequently moving it from one place to another where it could be easily misplaced. Thus, it is very much unlike a handheld remote controller, where a single unit is intended to be moved among multiple points of use. Another purpose of this design is to have it sufficiently small that it is visually and physically unobtrusive when mounted on a larger object. Alternatively, it may be completely hidden, e.g. on the underside of a table or chair or other object.

In addition to its small size, its light weight makes it easy to mount on larger objects wherever control is desired. Such a larger object can be fixed, such as a wall or railing, or a piece of furniture where it can be mounted in an unobtrusive location, e.g. under the edge of a table or under the arm of a chair. Such a larger object can be movable, such as a clipboard, television remote controller, or crutches. Thus, unlike a stick-on wireless wall switch, the controller is intended and configured for unobtrusive or concealed locations, or locations where it does not interfere with the use of an object such as clipboard, television remote controller, or crutches. Also, clutter on a table can be reduced by mounting the miniature remote controller beneath the edge of a table. Further, some people consider larger controllers to be unsightly and prefer them to be concealed, which is facilitated by the miniature remote controller100.

If desired, the controller can be repositioned, such as to a different piece of furniture or another place on the same piece of furniture. The miniature remote controller may be removably mounted to the larger object by various means such as double-sided adhesive pads, magnets, suction cups, a tiny screw, adhesive Velcro© tape, snap fasteners with one part of the snap fastener attached to the miniature remote controller and the other part removably attached to the larger object, or adhesive putty. In one embodiment, 3M brand Command® adhesive strips are used. This product is a single-use pressure-sensitive adhesive pad incorporating a special tab mechanism for easy removal without damage or residue to the surface. This product may be used in combination with other attachment means such as Velcro© tape or magnets, and may incorporate a part between the miniature remote controller and the larger object.

The miniature remote controller100transmits a radio frequency signal to control a device, but could, in another embodiment, emit an optical signal. In one embodiment, the miniature remote controller100controls a light bulb by means of the light bulb adapter ofFIG. 5which includes an antenna2to receive the signal. However, receivers for the miniature remote controller's signal are not limited to adapter devices, as discussed in connection withFIGS. 5 and 6below.

FIG. 2depicts the miniature remote controller according to one embodiment. It comprises a housing or body118. The top surface105of the body comprises a top button104and a bottom button106disposed thereon. The top button has a dimple or a bump or other distinctive feature such as a color to distinguish it both visually and by touch from the bottom button.FIG. 2shows an example where buttons102and106have a triangular shape, and where the top button is a right-side up triangle and the bottom button is an inverted triangle indicating “up” (brighter) and “down” (dimmer) respectively. This is meant by way of example, and not to be limiting. The buttons could be square or round, for example. However, the triangular button shape, the opposite arrangement of just two buttons, and the marking on one button make the controller very user-friendly, are in deliberate contrast with conventional remote controllers having many buttons and even a display. A miniature rocker switch may also be used instead of two buttons.

The housing or body118and consequently the top surface105are sized to support a minimal amount of buttons, for example, at least one button, but no more than two buttons, e.g., buttons102and106. Furthermore, the buttons102and106are sized to be actuated by a user's finger tip of average size, and no larger. The shape of the housing body108is shown in the figures to be rectangular, but that is only an example. It could have an oval shape, circular shape, etc. While the housing118can be held in a user's hand, its size and shape is configured so that it is not used when held in a user's hand, but rather only for use when it is mounted to a larger object. The buttons102and106are one example of finger actuation means. Thus, the miniature remote controller100is configured to be a mountable remote controller, not for hand-held use, and of such a small size that when it is mounted on a larger object, it is not visually distracting or obvious.

FIG. 2depicts one embodiment of a miniature remote controller100configured to act as three independent remote controllers which could, for example, control three receivers, such as those described herein. The controller100incorporates a battery116within its housing118to provide power for processing and transmission of signals. In one embodiment, battery116is absent and power is derived from the force of the user's finger on a button or other finger-actuated component.

As described herein, users may want to have more than one miniature remote controller mounted at a given location. They will be sold in assorted colors for this purpose. However, if too many miniature remotes are mounted together, their small size becomes defeated. For this situation, a three-position selector switch120may be incorporated on the side of the miniature remote controller100that can slide among multiple switch positions shown by tic marks at reference numerals124a, b,andc. In this example, there are three switch positions for the selector position, but this is only an example. There may be two or more than three switch positions for the selector switch.

The selector switch operates as follows. Each transmission from the miniature remote controller includes the command desired, an Identification Number for the particular controller, and redundancy for error amelioration. There are hundreds of millions of possible Identification (ID) Numbers. When selector switch120is moved to another position, it changes the Identification Number of the controller thereby becoming, in effect, a different controller. Accordingly, one miniature remote controller then functions as three different controllers without an increase in size. The three controllers thus simulated are completely independent, meaning each can be linked or unlinked to any controlled appliance (e.g., light or fan) without affecting the linkages of the other two simulated controllers.

FIG. 3is an exploded view of the mechanism for removably attaching the miniature remote controller100ofFIG. 2to a selected surface. Adhesive assembly140incorporates a readily removable adhesive strip144such as the 3M brand Command® having a backing paper142awhich is removed before applying the left side of adhesive strip144to an object. 3M brand Command® adhesive incorporates an extended tab146for removal from the object after it is applied.

The miniature remote controller incorporates a plastic slider mechanism130with a roughened rear surface132to which is attached the right side of adhesive strip144after removal of backing paper142b. Plastic slider mechanism130is attached to the body118of the miniature remote controller by projecting ribs134aandbwhich slide in slots122aandbon the back of the miniature remote controller body118inFIG. 3, thereby allowing the user to slide the miniature remote controller up and down on the rib structure. In one embodiment, the controller body118can be completely removed from the plastic slider with extra force; in another embodiment it cannot. Removing it provides extra convenience but may cause pieces to be lost.

After installation, the user slides the miniature remote controller100downward on the rib structure so as to hide the Command® adhesive tab146. To remove the miniature remote controller100from the object on which it was mounted or attached, the user slides the controller100upward to expose the tab146, grabs the tab146firmly and pulls it downward, stretching it and cleanly removing the adhesive from both the controller and the object.

In one embodiment, the same plastic slider mechanism130allows the miniature remote controller body to be temporarily removed from its mounting position with extra force, leaving the plastic slider mechanism behind still glued in place. This is useful for a new linking or unlinking and various other purposes. Physically this is accomplished by a slight increase in the size of the ribs at their top and a slight decrease in the size of the slots at their bottom, not unlike the mechanism used to make the cap of a plastic pen “click” onto it. The plastic slider concept also allows for alternate plastic sliders of different shapes, for instance a plastic slider curved on the outside for mounting on tubular objects such as round chair-arms, rails, crutches, etc.

FIG. 4is a block diagram of transmitter circuitry such as might be incorporated within the miniature remote controller100shown inFIGS. 1-3.

In one embodiment, power is supplied to the controller by battery116which may, for example, be a 3-volt lithium-ion button battery. In another embodiment, batteryless power system200harvests power from the user's button-pressing action. Piezoelectric or magneto transducers may be used. The batteryless embodiment uses specially designed power conservation circuitry throughout the controller. Each miniature remote controller has a preassigned Identification Number212embedded within it at manufacture. If a selector switch120is used, multiple Identification Numbers212are required as described in connection withFIG. 2. A simple way to embed the ID Number212is to include it in the firmware permanently installed with each processor210. Read-Only memory, ROM, and other techniques are also available.

To conserve power, processor210and transmitter208may be designed so that they have a “sleep” state drawing negligible power when not in use or battery116will be quickly drained. The rfPIC12F675 is an integrated circuit chip from MicroChip® for use at 433.92 MHz combining the functions of processor210and transmitter205. This chip can be asleep for many years without depleting even a small battery116. An alternative circuit requiring additional components (not shown) eliminates all sleep current by disconnecting the rfPIC12F675 completely from battery116unless button102or106is pressed.

Software preloaded into the processor210(firmware) configures the transmitter circuitry and controls all its operations. The inputs to processor210are wires from up button102, down button106, and selector switch120if present. Ground connections (not shown) on the other terminal of button102,106or selector120complete the circuit. Software in processor210monitors and times all button activity to infer the user's intentions. The software then generates the exact bit pattern to be transmitted and passes it to transmitter208. Software also detects a stuck button, shutting down until it is released to conserve power.

The output of processor210is a binary signal turning on and off transmitter208and, optionally, a second signal shifting its frequency between one of two nearby values (Frequency-shift keying or FSK). FSK is somewhat more efficient than the simpler ASK (Amplitude-Shift Keying) where the RF carrier is simply on or off. The rfPIC12F675 is capable of either. Transmitter208may be as little as a single RF transistor and supporting passive components. Transmitter208typically is combined with a crystal204to precisely fix the transmitted carrier frequency. In the rfPIC12F675 crystal204operates at 1/16 of the carrier frequency, being multiplied up by a PLL (Phase-Locked-Loop) within the chip. In the single-transistor implementation crystal204directly supplies the carrier frequency as a harmonic. Some transmitters go without any crystal204, which requires hand-tuning each unit and considerably more frequency tolerance.

Loop antenna206radiates the RF signal. It is a wide trace around the periphery of the printed circuit board just under front surface105of miniature remote controller100. Passive C and L components (not shown) resonate antenna206at the selected carrier frequency for efficiency. The single-transistor, no crystal, transmitter208implementation mentioned above may use antenna206as part of its tank circuit.

Table 1 below lists examples of the possible commands that may be transmitted by miniature remote controller100, along with their meaning, the user action each requires, and the action the receiver will take if not otherwise clear. “Soft transition” refers to turning a light on or off gradually. “Slewing” refers to the user holding down a button until the light reaches the brightness she desires. Note that the transmitter does not transmit continuously when a button is held down, to conserve power, instead transmitting only a brief start and stop command. PRESET is the user's preferred light level, which the receiver interprets as the last level she slewed to. Empirically determined timing constants, preloaded at manufacture and identified at the bottom of Table 1, help infer user intensions.

The command list of Table 1 is by way of illustration only. It will be appreciated that relatively minor software changes can add new commands or modify the ones listed to meet changing requirements.

All commands transmitted twice with checksum.

Table 2 is the state diagram used by the transmitter software residing in processor210to implement the command list of Table 1. Note that commands from the Command List are issued on transitions from one state to another. For clarity, some states are combined in this table. For example “one button pressed” is really two states: “UP button pressed” and “DOWN button pressed.”

State 4, ‘responsive slew mode,” requires some explanation. Ideally, when the user desires a particular brightness she holds down the appropriate button until it is reached and stops. In practice, however, she is likely to overshoot and/or want to go back and forth to find the exact level desired. The software detects this situation and goes into ‘responsive slew state.’ In this state, a tap of a button is interpreted as a brightness tweak rather a turn-on or turn-off and the response is a fraction of a second faster.

FIGS. 5 and 6show miniature remote controller100controlling five different kinds of receivers compatible with the system disclosed. For clarity, each controller is shown controlling one and only one receiver. More complicated arrangements are allowed, see discussion ofFIG. 7below. Indeed, any arrangement is possible with the system disclosed herein.

A first kind of receiver for a control signal from miniature remote control100ais light socket adapter1. This adapter is screwed into a standard socket and controls a light bulb screwed into it. Its mechanical and electronic particulars are disclosed and the aforementioned co-pending patent application.

A second kind of receiver is located in pod11of a CFL or LED light bulb5. The long life and high initial cost of CFL and LED bulbs justify including additional electronics within their pods11. Bulb5is screwed by its base17into a fully powered socket not on a dimmer circuit and then controlled through its radio receiver.FIG. 9, described hereinafter, is a block diagram of the electronic circuitry within light bulb5. In one embodiment, light bulb5is sold bundled with two miniature remote controllers100bprelinked to it (see Linking and Unlinking, described hereinafter). In one embodiment, even when a miniature remote controller is prelinked to a particular receiver, the user may unlink or link it at will to that receiver or any other after purchase.

A third kind of receiver is located in lamp socket assembly7. If the body of lamp socket assembly7is insulating, for example Bakelite, antenna2would be embedded in, or just within, that insulating body. If the body of7is conducting, such as the popular brass type, a ring of brass2would be isolated from there rest of the body to act as antenna2. A break in that antenna ring2, not shown, is useful to maximize its sensitivity. The antenna2is described further hereinafter in connection with the receiver circuitry.

In one embodiment lamp socket assembly7has a user control on it; in another embodiment there is no user interface except through miniature remote controller100c. One embodiment of the user control is control ring3which the user rotates clockwise for UP and counterclockwise for DOWN and which is spring loaded to return to a neutral position between UP and DOWN. Alternatively, a more familiar user interface would be a toggle bar through the body of lamp socket assembly7or a rotary dial on it. The control ring3shown is more user-friendly because it works the same from all directions. The table lamp need not be rotated to a particular orientation on the table nor would the user need to grope under the lampshade is locate the control.FIG. 10, described hereinafter, is a block diagram of the electronic circuitry within lamp socket assembly7.

A fourth kind of receiver is located in outlet adapter9. It functions plugged into a wall outlet by its plug13with the appliance to be controlled in turn plugged into its outlet15. Unlike the other four receivers inFIGS. 5 and 6, outlet adapter9is non-dimming. It operates ON and OFF only. Any appliance may be plugged into its outlet15and turned ON or OFF remotely, including appliances drawing much more current than a light bulb. The UP button on miniature remote controller100dfunctions as ON and the DOWN button functions as OFF. This interpretation is handled by the receiver in outlet adapter9without modification to controller100d. Non-volatile memory in the receiver (described hereinafter) enables the outlet adapter to remain ON across a power interruption, unlike competing devices. Optionally, there may be an on-off switch on the body of outlet adapter9which controls it locally and without conflict with remote control100d.FIG. 11, described hereinafter, is a block diagram of the electronic circuitry within socket adapter9.

A fifth kind of receiver is located in wallswitch dimmer19ofFIG. 6and is intended as a replacement for an existing wall dimmer switch. Wallswitch19is hardwired to light fixture25through pre-existing building wiring23. It is controlled either by its own switch, such as rocker switch21shown or by signal112received from miniature remote controller100. Neither method of control excludes the other or takes precedence over it. To improve reception, its antenna2is located close to the surface of the switchplate, not shown.

Wallswitch19has two features not present in any of the other receivers described above.

Firstly, it may be in the same AC circuit with one or more additional wallswitches already wired to share control of light fixture25in the manner of a so-called three-way or four-way switch. For example, wallswitch19may be at the top of a stairs and a remote wallswitch controlling the same light at the bottom of the stairs. Remote wallswitches would be replaced by compatible remote switches, not shown. These compatible remote switches are much simpler than wallswitch19. They do not include a receiver or processor—just a rocker switch21, or equivalent, and means to communicate its activity back to main wallswitch19via existing wiring. Wallswitch19will receive user commands from any number of such remote wallswitches, from its own switch19, or by radio signal112from any number of miniature remote controllers without prejudice or conflict among them.

Secondly, wallswitch19has, in one configuration, the ability to transmit commands as well as receive them. Thus wallswitch19could dim a table lamp equipped with lamp socket assembly7, along with its own chandelier even though table lamp outlets, under electrical code, normally are not wired to dimmer switches. Wallswitch dimmer19becomes linked (see Linking and Unlinking described below) to another receiver by assuming the Identification Number of a particular miniature remote controller brought near it with both buttons on both devices pressed and held for two seconds. This process is used, rather than giving wallswitch19its own ID number, because the wallswitch is not portable and therefore generally cannot link on its own to another receiver. By “lending” its ID number, the particular miniature remote control can then act as proxy for wallswitch19and link or unlink it to distant receivers.FIG. 12, described below, is a block diagram of the electronic circuitry within wallswitch19to accomplish all the above. It will be appreciated that rocker switch21is just one example of user input at wallswitch19. It could be, for instance, two large buttons square buttons or any of an unlimited number of other possible designs.

Linking and Unlinking

A remote controller is said to be linked to a receiver if the receiver will accept commands from that remote controller. A remote controller is said to be unlinked to a receiver if it is not linked to it. Linking is the operation of becoming linked and unlinking is the operation of becoming unlinked.

The receiver must know whether it is to respond or not respond to the signal from a given miniature remote controller, i.e., whether it is linked or unlinked to that particular controller. Several systems are in common use for linking and unlinking of remote controllers and their receivers. Most take the form of entering special codes and/or pressing a “learn” button or using a special tool on one or both units. For maximum flexibility, the remote controller here incorporates means for easily linking and unlinking to a given receiver at the sole discretion of the user, and links and unlinks in a more intuitive and user-friendly manner than any of these existing systems. The user holds the miniature remote controller in close physical proximity to the light or fan or similar appliance and presses both buttons102and106at the same time for two seconds. The receiver detects this action and the higher signal strength and authorizes the linkage. This same procedure is used for linking or unlinking. This linking and unlinking process is described in more detail hereinafter in connection withFIG. 8.

Linking a remote controller to a receiver does not preclude the receiver from being linked to other remote controllers, nor does it preclude the remote controller from being linked to other receivers. In other words, a given miniature remote controller may be linked or unlinked from a given receiver without affecting the relationship(s) between that remote controller and other receivers or the relationship(s) between that receiver and other remote controllers. Arbitrary combinations are possible without interference with one another.

FIG. 7depicts one such arbitrary combination, wherein100athrough100gare seven miniature remote controllers, and110is an eighth miniature remote controller with only an OFF button.5a, b, andcare three light bulbs, and112is a radio frequency wave moving in the direction indicated by the arrow beneath it, thereby providing a link to the designated bulb.

InFIG. 7, the following combinations are shown: (a) five miniature remote controllers100a, b, e, fand110control one light5a, (b) two lights5aand5bare controlled by one controller100b, and (c) one controller110can turn off all three lights5a, b, andc. All of the controllers and all of the lights can be in a single room and operate without interference among each other. Accordingly, a person can sit in one chair in a room where miniature remote controllers are placed and control a single light or a set of several different lights, and move to another chair in the same room or a nearby room where controllers are placed and control the same lights, other lights, or the same plus other lights.

FIG. 8is a flow chart of the receiver software operations with emphasis on linking and unlinking. A stream of binary data is output by radio receiver166to processor176. It is the job of this software executed by processor176to interpret and act on it.

When no signal is present there is still a data stream. The AGC in radio receiver166“opens up” and converts RF noise into zeros and ones. That noise may be random or from manmade sources.

A compatible transmitter, such as the miniature remote controller ofFIGS. 1,2, and3, transmits its data packets including various redundant information. Specifically, a data packet comprises:(a) an unchanging header(b) the transmitter's Identification Number (28-bits)(c) a command code(d) byte parity bits and a checksum.

All the above is transmitted a second time with a deliberately unpredictable gap between the two.

Transmission of each packet requires about 0.1 second. If the software180recognizes valid data but cannot recover it without error, the data is ignored and discarded and the system begins listening again. If identical data is received error-free twice in a row closely spaced, the second packet is ignored. Error correcting coding allows certain types of bit errors to be corrected and the data rendered usable.

Once valid data is in hand, software182examines the imbedded command code representing the user's intentions.

If the received command is other than Link/Unlink, receiver software186immediately checks whether the transmitter's Identification Number matches any in its authorized (linked) list located in the receiver's non-volatile memory. If the transmitter is unauthorized (not linked) its command is discarded, has no effect whatsoever, and that transmitter remains unlinked.

If, on the other hand, the transmitter is authorized its command is executed188. When that execution results in a new level (brightness), including OFF, for the controlled light, which it normally does, that new light level is recorded190in non-volatile memory178for restoration should a power interruption occur.

If the received command is Link/Unlink a different chain of events occurs. Link and Unlink use the same transmitted code because our one-way communication leaves the transmitter no way of knowing whether it is already linked to a given receiver. For Link/Unlink, and only for that command, the received signal strength is interrogated184. Only if signal strength is very high, indicating the transmitter is very near, does the software proceed.

If the signal strength is very high, the transmitter's Identification Number is checked192against the authorized list. If it is absent, it is added194(Linking) and if it is present, it is deleted198(Unlinking). If the list is full (63 authorized transmitters), preventing a Linking, the software deletes the oldest ID and proceeds with the Linking.

If a light bulb is present, successful Linking or Unlinking is acknowledged to the user by flashing the light twice. The flash pattern is different for Link196and Unlink199so that experienced users will recognize which has occurred. “Link” is dot-dash and “Unlink” is dash-dot.

Receiver Circuitry and Operation: Inside the Light Bulb

FIG. 9is a block diagram of receiver circuitry such as might be incorporated within light bulb5shown inFIG. 5. POWER SUPPLY168converts the incoming 120 VAC power (from the lamp wiring) to low-voltage DC, in this case 3.3 volts, for powering chips and other components of the receiver. The incoming radio signal is received by an antenna2within the light bulb pod11ofFIG. 5or other means. The signal from the antenna2is conditioned before being coupled into receiver166for amplification and detection. Signal conditioning164may comprise impedance matching among the various RF components, SAW (Surface Acoustic Wave) filtering to suppress out-of-band signals, and, optionally, preamplification near the antenna2.

Receiver166typically incorporates an integrated circuit chip designed for the frequency band selected. For example, rfRXD0420 is an integrated circuit receiver chip from MicroChip® for use at 433.92 MHz. The receiver chip provides Low Noise Amplification (LNA) heterodyning, mixing, Automatic Gain Control (AGC) and other functions. The receiver chip is supported by external components not shown, most importantly a quartz crystal to set the frequency and an Intermediate Frequency (IF) filter to reject nearby signals. The output of the Receiver is an asynchronous binary data stream indicating, in the simplest Amplitude Modulation (AM) mode, presence or absence of the RF signal by a one or zero respectively. From this binary data, processor176extracts commands from remote control transmitter devices, such as the miniature remote controller ofFIG. 2, interprets them, and executes them. Of particular importance (for linking and unlinking) receiver166also puts out a slowly-varying analog voltage equal to (approximately) the logarithm of the RF signal strength which it derives from its Automatic Gain Control (AGC) activity.

Processor176typically is a self-contained integrated circuit microprocessor, such as PIC12F683 processor chip from MicroChip. Software preloaded into the chip (firmware) configures the receiver circuitry and controls all its operations. A small non-volatile memory (NVM)178holds data across a power failure. (In the PIC12F683 integrated circuit chip NVM178is included in processor176.) The operation of processor176interpreting and acting upon the data stream from receiver166is detailed inFIG. 8, above.

The output of processor176controls light bulb driver177. “Light bulb driver” refers to the circuitry in the electronics pod11inFIG. 5near the base of CFL bulb5, or the corresponding circuitry in an LED bulb. The pod circuitry supplies current and voltage to the actual light-producing element(s) and is particularly complex in the case of a dimmable CFL.

The interface174of light bulb driver177with the remainder ofFIG. 9may be implemented several ways depending on the volume of production anticipated. Inserting the circuitry ofFIG. 9within the pod11can be achieved with the cooperation of the manufacturer of bulb5. Generally, greater integration of the new circuitry with the existing circuitry results in lower per-unit cost, smaller size, lower power, and better dimming performance but at increased engineering and tooling cost.

The lowest level of integration between new and existing circuitry, represented by interface174, is to keep them entirely separate and simply supply power to light bulb driver177via a TRIAC. (This is similar to the arrangement ofFIG. 10but without buttons165aand165b, in effect simply moving the electronics ofFIG. 10from light bulb socket7into bulb pod11unchanged.)

A second level of integration would be to supply driver177with full AC power at all times, as shown at the bottom ofFIG. 9, but then intervene in driver177at a point where it controls bulb dimming with a signal from processor176, buffered as required by interface174(shown schematically as an amplifier). That input could be digital or analog, as required by driver177, with analog requiring a digital-to-analog (D/A) converter within interface174. Any non-linearity in the process can be corrected easily in processor176software.

A third level of integration would be to share subsystems between the two, especially power supply168and processor176. Current light bulb drivers177have no processor but could benefit from one.

The highest level of integration would be to combine functions of driver177and the rest ofFIG. 9into a single Integrated Circuit (IC) chip. Early CFL bulbs had drivers177not deployed on ICs but are currently evolving toward the use of ICs.

Receiver Circuitry and Operation: In a Lamp Socket Assembly

FIG. 10is a block diagram of receiver circuitry such as might be incorporated within the lamp socket assembly7shown inFIG. 5. POWER SUPPLY168converts the incoming 120 VAC power (from the lamp wiring) to low-voltage DC, in this case 3.3 volts, for powering chips and other components of the receiver. The 120 VAC input power is also passed through to the AC output (chopped when dimming) by the TRIAC172which is shown wired in the manner used ubiquitously for dimming light bulbs. Two ampere TRIAC172will easily drive a 150 watt light bulb.

The incoming radio signal is received by antenna2in the lamp socket assembly ofFIG. 5or other means such as the use of power wiring as an antenna. Conditioning the signal from antenna2, detecting it in receiver166, and interpreting it in the processor all occur as described above in connection withFIG. 9.

The output of processor176here is a binary signal that fires TRIAC172through an isolation transistor, indicated schematically as amplifier174. After firing, TRIAC172remains conducting until the next zero-crossing of the AC current. Processor176includes timers the software uses to accurately set the firing times of TRIAC172according to the brightness of the light desired. If the light is to be full OFF, TRIAC172never fires. If the light is to be full ON, TRIAC172is driven to fire continuously or nearly so.

The bulb screwed into lamp socket assembly7is controllable by any miniature remote controller100that is linked to it. Optionally, it may also be controlled by a hand control on the lamp socket assembly itself. UP button165aand DOWN button165brepresent this hand control schematically and are not meant to limit the hand control to actual buttons. Another implementation is a bar type switch passing diametrically through socket assembly7or a twist knob, both structures common on such socket assemblies. However, unlike these common switches, their equivalent here would be spring-loaded—returning to a rest position when released. This is needed to prevent conflict among different controls of the same light. If the user interface means has mechanical memory of where the user left it, an incoming radio signal could put the light in a state contradicting that memory. For example, if a rotary knob were turned all the way up and then an incoming radio signal turned the light down, the knob would be incapable of turning it back up because it cannot go any further. Momentary switches, represented schematically as push buttons inFIG. 10, solve this conflict. One embodiment for a lamp socket control is control ring3, as shown inFIG. 5. The user rotates it clockwise to engage the momentary switch165afor UP and counter-clockwise to engage the momentary switch165bfor DOWN, with control ring3returning to its neutral position when released. Unlike conventional socket assembly switches and knobs, the control ring3is the same from all directions, eliminating the need to feel around under the lampshade to locate the switch.

Software in processor176treats inputs from momentary switches165aand165bexactly as commands coming in over the air via antenna2, i.e. as if the switches were on their own miniature remote control. In other words, user actions on switches165aand165bare interpreted according to Table 1 and Table 2 above except no LINK command is recognized. The FLASH command, requiring165aand165bpressed together, may or may not be available and may be assigned to a different user action than shown in the Tables.

Another input to processor176is the AC input voltage itself, buffered by a very large resistor170and treated as a binary signal. This signal is required by the software to control TRIAC172and fire it in a precise timing relationship with the AC voltage. Noise on the AC power line is suppressed by the software. This 60 Hz input is also used to time the “Flash” function so that multiple lights flashing stay perfectly synchronized, even when they're on different circuits. Note that inFIG. 10andFIG. 12, the “hot” side of the incoming AC becomes ground for the electronic circuitry. This is required because TRIAC172must be in the “hot side” of the AC line and hence its gate must be driven relative to “hot,” forcing the entire circuit shown, including receiver166, to be floating at 120 VAC.

In one version of the software, NVM178is used for two purposes. First, it contains the list of the Identification Numbers of remote controllers linked to this receiver and hence authorized to control it. The PIC12F683 integrated circuit chip allows up to 63 remote controllers with 28-bit ID numbers to be linked to the receiver at one time. The other use of NVM178is to store the current light level. This unique feature of the receiver circuitry disclosed herein allows lights to return to their previous brightness after a power failure. The user does not need to reset the lamp socket assembly's circuitry after a momentary power interruption or if a particular socket is accidentally turned off. A brand new lamp socket assembly powers up with the light full ON.

Receiver Circuitry and Operation: In a Plug and Outlet Adapter

FIG. 11is a block diagram of receiver circuitry such as might be incorporated within the outlet adapter9shown inFIG. 5. RF controlled socket adapters, not compatible with the system described herein, are commercially available in both dimmable and on-off only configurations. The dimmable configurations are intended for a table lamp or the like but are not good practice, and possibly in violation of electrical codes, because motor driven, electronic, or heating appliances might be plugged into them, possibly overheating or behaving unpredictably when powered by the chopped waveform used to dim light bulbs. For that reason, only an on-off version is presented inFIG. 11. A dimmable version is possible, using the circuit ofFIG. 10, if such a version were desired.

The on-off socket adapter ofFIG. 11uses relay173instead of TRIAC172. Relay173may be driven directly by processor176or through a transistor buffer174based on various engineering considerations. Preferably, relay172is rated for the full current of an outlet socket, which is 15 amperes AC in the U.S. A TRIAC is not practical at 15 A in this application because heating and wasted power would be high. Relays of the single-coil type173shown inFIG. 11continually dissipate only a small amount of power, tens of milliwatts, in the ON position. If desired, even that power can be eliminated using a two-coil latching relay, not shown, which is more expensive and may require a second signal from processor176. Note the difference in AC polarity betweenFIG. 11(bottom) and the TRIAC circuits ofFIGS. 10 and 12. Because relay173provides isolation, internal ground is the same as AC neutral inFIG. 11.

Outlet adapter9(FIG. 5) may optionally be configured with its own ON-OFF switch, shown as165aand165binFIG. 11. This would be a momentary-ON, momentary-OFF switch, not a toggle switch, to preclude conflict with incoming RF commands as discussed in connection with165aand165binFIG. 10.

Unlike competing products, outlet adapter9remembers its state across a power failure using non-volatile memory178and the same software that remembers light brightness in dimming receivers. Consequently, a fan will not shut off on a hot day just because the power flickered. See the description of software flow chart shown inFIG. 8, item190, for further information on this feature.

Receiver Circuitry and Operation: In a Wallswitch Dimmer

FIG. 12is a block diagram of receiver circuitry such as might be incorporated within wallswitch dimmer19shown inFIG. 6. One embodiment of the wallswitch dimmer19also includes transmitter208whereby wallswitch19may control a light or appliance7that is not wired to that wallswitch, such as a table lamp or a light in an adjacent room. As with the other receivers described above, what is or is not controlled is at the discretion of the user and may be changed at will and in arbitrary combinations according to the system herein.

The receiver portion ofFIG. 12is TRIAC-based, like that inFIG. 10, except a larger TRIAC172is required to meet the 600 watt drive requirement associated with wallswitch dimmers in the U.S. When driving the full 600 watts, TRIAC172dissipates significant heat and the heat-sink requirements of conventional dimmer switches apply.

Wallswitches often are mounted in metal boxes so that antenna2is desirably near the front surface and the switchplate (not shown) is desirably plastic or ceramic. Transmit antenna206is located similarly and may or may not be the same component as antenna2. Momentary switches165aand165bmay take a variety of forms. In the embodiment shown inFIG. 6, they are the two ends of rocker switch21so that pressing its top portion activates UP switch165aand pressing its bottom portion activates DOWN switch165b. Rocker switch21, unlike an otherwise-equivalent two button embodiment, would normally not allow activating both switches165aand165bat once. However, this feature is desired to simplify linking and unlinking when optional transmitter208is present, as described in connection withFIG. 6. In that case, rocker switch21would be configured mechanically so that both its top and bottom can be pressed at once.

Signal conditioning164, receiver166, processor176, non-volatile memory178, resistor170, power supply168, gate isolation174, TRIAC172, and switches165aandbinFIG. 12operate as those same components do in the configuration shown inFIG. 10and are described above. However if transmitter208is present, local switches165aand165bshould be capable of initiating a LINK command and all of Table 1 (button interpretation) commands apply for operating the circuitry shown inFIG. 12like the remote controller shown inFIGS. 1-3described above, unlike the buttons of lamp socket assembly7(FIG. 10), which cannot generate a LINK command. The receiving software for processor176inFIG. 12operates the same as inFIGS. 9,10, and11according to flow chartFIG. 8. As discussed in connection withFIG. 6and unlike miniature remote controller100, the transmitter ofFIG. 12has no pre-assigned Identification Number. Instead, it assumes the Identification Number of a particular miniature remote control100if and when a LINK command is received from that remote controller while switches165aand165bare both pressed. Wallswitch19uses that Identification Number until it is changed by another remote controller100or cancelled by the original one. If wallswitch19has no authorized Identification Number at a given time, it will not transmit.

Many existing wallswitch dimmers are wired together in pairs, or more, to control a light fixture from multiple points, such as the top and bottom of a stairway. Only one wallswitch19is wired to the light fixture and only that one has the TRIAC172and other features ofFIG. 12. The others are much simpler. Compatible remote wallswitches are wired into central wallswitch19through its input207and the existing wiring between them. Buffering and other minor interface components on input207are not shown. Wallswitch19responds to UP and DOWN switches on remote wallswitches.

All of the above descriptions are intended by way of example only.