US20070137075A1 - Pulse Width Modulation Drive and Method for Ornaments with Moveable Components - Google Patents

Abstract

A decoration device may include a low-friction drive line and a PWM controlled motor that reduces or eliminates the gearing needed to achieve appropriate speed and torque at the motor output shaft. In preferred embodiments, the decoration device is an ornament that includes a low friction interfaces to accommodate relatively low torque output from the PWM drive motor. In certain embodiments, the PWM controller drives a motor at low speeds suitable for ornament applications.

Description

CROSS-REFERENCE TO THE RELATED APPLICATION(S)
• This application is a continuation of U.S. application Ser. No. 11/251,606, filed by Phu Dang et al. on Oct. 14, 2005, and entitled “PULSE WIDTH MODULATION DRIVE AND METHOD FOR ORNAMENTS WITH MOVEABLE COMPONENTS.” The entirety of this previous application is incorporated by reference herein.
BACKGROUND
• Decoration devices may be used to enhance the appearance of a room or an object or to provide entertainment. For example, some decoration devices may be in the form ornaments that are hung from a wall, a mantle, or a tree so as to enhance the overall decorative appearance of that wall, mantle, or tree. In another example, a decoration device may be adapted to rest upon a tabletop or other surface and may provide entertainment for those viewing the device.
• In some circumstances, decoration devices may include motion, colors, shapes, or lights to provide a appearance that is associated with a particular season, holiday, event, or theme. A powered ornament device may include at least one component that is movable relative to another component. For example, a traditional children's music box may include a figurine (e.g., a dancer) that rotates relative to a stationary base as a musical sound is emitted from the box.
• Electrically powered, movable ornaments and other such decoration devices typically include an AC motor to drive the motion of the movable component. Such AC motors are typically driven off 120 V alternating current which is readily available in residential environments. The AC motors generally rotate at set rotational speed for a given load. That rotational speed often significantly exceeds that desired for ornament applications, so the AC motor output shafts have been coupled to gearbox in order to reduce the speed. With a decrease in shaft speed comes an increase in torque and this increased torque is usually substantially more than that required to drive the frictional and inertial loads in a typical ornament application.
• Pulse-width modulation (PWM) controllers may be used in lieu of gearing to control motor speed, but PWM techniques have generally been considered unacceptable for ornament applications because the throttling necessary to achieve the appropriate shaft speed generally yields a torque that is insufficient to drive the ornament or to drive the ornament smoothly given variations in drive line friction. Moreover, use of PWM controlled motors would substantially increase manufacturing costs due to the combined cost of the PWM microcontrollers and the complex gear systems that would have be used to account for the low torque output of PWM controlled DC motors. For both of these reasons, AC motors with reduction gearing have been used in lieu of PWM controlled motors in ornament applications.
SUMMARY
• A decoration device may include a low-friction drive line and a PWM-controlled motor that reduces or eliminates the gearing needed to achieve appropriate speed and torque at the motor output shaft. In preferred embodiments, the decoration device is an ornament that includes a low friction interfaces to accommodate relatively low torque output from the PWM driven motor. In certain embodiments, the PWM controller drives a DC motor at low speeds suitable for ornament applications. In other embodiments, the PWM controller may control the speed of an AC motor by adjusting the frequency of an alternating signal.
• These and other embodiments may provide one or more of the following additional advantages. First, the a movable ornament of a decoration device may be driven using a PWM-controlled motor so that the acceleration and/or speed of the movable ornament is readily adjustable by the user. Second, the gearing necessary to achieve the appropriate rotational velocity may be eliminated or reduced, thereby reducing the net component costs. Third, because the gearing may be eliminated or substantially reduced, the gear noise emitted during the motion of the ornament may likewise be eliminated or reduced. Fourth, design flexibility may be achieved in that the same PWM controller and motor assembly may be used in a variety of different ornaments having different rotational velocity design parameters by simply modifying the nonvolatile memory settings in the PWM controller to achieve a different shaft speed.
• The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
• FIG. 1ais a front view of the decoration device in accordance with some embodiments of the invention.
• FIG. 1bis a rear view of the decoration device ofFIG. 1a.
• FIG. 2 is a cross sectional view of the decoration device ofFIG. 1a.
• FIG. 3 is a cross sectional view of a decoration device in accordance with some embodiments of the invention.
• FIG. 4ais a cross sectional view of a portion of the decoration device ofFIG. 3.
• FIG. 4bis an enlarged view of a portion of the decoration device ofFIG. 3.
• FIG. 5 is an enlarged view of an alternate embodiment of a portion of the decoration device ofFIG. 3.
• FIG. 6 is a block diagram of a controller in accordance with some embodiments of the invention.
• FIG. 7 is a diagram of a motor control circuit in accordance with some embodiments of the invention.
• FIG. 8 is a block diagram of an embodiment of a controller.
• FIG. 9 is a flowchart of the operation of some components of a movable decoration device controller in accordance with some embodiments of the invention.
• Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
• Referring toFIGS. 1aand1b, adecoration device100 may include anattachment mechanism102 and anornament structure104. In this embodiment, theattachment mechanism102 comprises ametal ring106. Themetal ring106 is coupled to a decorative element, such as Santa's Workshop108 near the top of theornament structure104. As such, theattachment mechanism102 may releasably couple theornament structure104 to an external object, such as a hook on a wall, a doorknob, a railing, or a branch of a Christmas tree. Theornament structure104 may also include a plurality of stand-offfeet110 molded into abase portion112.
• Thebase portion112 and abody portion114 of theornament structure104 may be fixedly coupled so as to define a front portion116 (FIG. 1a) and a rear portion118 (FIG. 1b). Thefront portion116 and therear portion118 may include one or more decorative elements that are configured to resemble patterns, characters, scenes, or words that may be associated with a particular season, event, or holiday. In this embodiment, the decorative elements on thefront portion116 and therear portion118 include a plurality of decorative Christmastrees120, a plurality of snow coveredrailroad tunnels122, atrain124, a substantiallycircular train track125, asnowman126, snow coveredmountains128, and a plurality of train stops including Santa's Workshop108, Sleighbell Center130, and Gumdrop Junction132. Thus, in this embodiment the sum of the decorative elements may be associated with the Christmas holiday season. It should be understood that other embodiments of thedecoration device100 may comprise decorative elements other than theelements108,120,122,124,125,126,128, and130. For example, other embodiments of thedecoration device100 may comprise decorative elements that are associated with an event (e.g., a birthday celebration) or associated with a season or another holiday (e.g., the Winter season or the holiday of Halloween).
• Still referring toFIGS. 1aand1b, some of the elements of the front andrear portions116 and118, such as Santa's Workshop108, Sleighbell Center130, and Gumdrop Junction132 may shed light on other portions of theornament structure104. Theornament structure104 may be substantially hollow such that an internal space (shown inFIG. 2) is defined between thebase portion112 and thebody portion114. One or moreinternal light sources134,136,138,140, and142 may be disposed at least partially in the internal space. Theornament structure104 may comprise a substantially transparent or translucent, light transmissive, and flame resistant polymer material, such as ABS (acrylonitrile butadiene styrene), or SAN (styrene-based plastic). Theornament structure104 may employ light from theinternal light sources134,136,138,140, and142 to provide lighting effects such as light-piping and edge lighting. In such circumstances, thefront portion116 and therear portion118 may have a low-level glowing effect. A translucent coating or paint coating may be applied to the exterior of theornament structure104 to enhance and control the quality of light that is emitted through the front andrear portions116 and118. The light emitted from thelight sources134,136,138,140, and142 maybe transmitted through the material of the front andrear surface portions116 and118 so as to emit substantially brighter light through some of the decorative elements on the front andrear portions116 and118 of theornament structure104. In this embodiment, the decorative elements that emit light transmitted through the front andrear surface portions116 and118 include, but are not limited to, thewindows144 of Santa's Workshop108, thewindows146 of Sleighbell Center130, and thewindows148 of Gumdrop Junction132.
• A plurality of electrical components (described in more detail below) may be disposed within theornament structure104. The electrical components may impart movement, sound, light, or all three in combination to at least a portion of thedevice100. The movement that may be imparted to a portion of thedevice100 may comprise rotational, linear, circular, reciprocating or other movement along a predetermined path. Further, the movement or motion may be imparted by a direct current (DC) or alternating current (AC) motor that may be controlled by a control system (as shown, for example, inFIG. 6). The movement may be interactive in response to an external or internal input, such as the position of a selector switch, a sound sensor input, a light sensor input, a positional sensor input, or a pushbutton input. Additionally, the variation in the external or internal input signals may function in coordination with the control system. The control system may drive a control signal in response to the inputs that may variably operate the motor, an audio output system, a visual output system, or all three in unison. The audio output system may output sound in coordination with the variation in the control signal through a plurality ofsound output ports150 disposed on therear portion118 of thedevice100. The visual output system may operate one or more of the previously mentionedlight sources134,136,138,140, and142 in coordination with the variation in the control signal.
• In the embodiment shown inFIGS. 1aand1b, motion may be imparted to thetrain124. The movement of thetrain124 may follow a substantially circular path that may be partially defined by the train trackselement125. The audio output system may output voice and train sounds. The visual output system may operate thelight sources134,136,138,140, and142. The audio output system and the visual output system may be synchronized to the motion of thetrain124.
• Arotary selector switch152 may be located on the front portion116 (FIG. 1A) of theornament structure104. In this embodiment, therotary selector switch152 may be positioned in any one of four positions. Theselector switch152 positions may be numerically coded, color coded, or otherwise identified. In the embodiment ofFIGS. 1aand1b, theselector switch152 positions are color coded and include switch position blue154, switch position red156, switch position green158, and switch position yellow160. Each of the switch positions may have a corresponding train movement cycle, train station destination, audio output (described, for example, in connection withFIG. 2), visual output pattern, or a combination thereof. For example, the switch position blue154 has the train stationdestination Gumdrop Junction132, a corresponding audio output, and turns onlight source142. The switch position red156 has the train station destination Santa'sWorkshop108, a corresponding audio output, and turns onlight source140. The switch position green158 has the train station destinationSleigh Bell Center130, a corresponding audio output, and turns onlight sources134,136, and138. The switch position yellow160 has the train station destination Grand Tour (e.g., thetrain124 travels along the tracks for a period of time past one or more of the previously describeddestinations108,130,132), a corresponding audio output, and turns onlight sources134,136,138,140, and142. After setting theselector switch152 to one of the four positions154-160 and pressing the “GO”pushbutton162 located to the right of theselector switch152, a new train movement cycle will start. Pressing the “Sound Effects”pushbutton164 to the left of theselector switch152 will play one of the audiooutput system train124 sound effects.
• Referring toFIG. 2, thedecoration device100 may have aninternal space164 that separates the front andrear portions116 and118 of theornament structure104. As previously mentioned, a plurality of electrical components may be disposed within theinternal space164 of theornament structure104. The electrical components may include a printed circuit board (PCB), a plurality of light emitting diodes (LEDs) or incandescent light bulbs, a speaker, a DC current motor, an AC current motor, integrated circuits (ICs), a power supply, or the like.
• The movement may be imparted to thetrain124 by aDC motor166 that is coupled to thebase112 of theornament structure104. TheDC motor166 may be subject to a low rotational friction load that may allow for a reduction in the size of the power supply. TheDC motor166 may include anoutput shaft168 that rotates when the motor is driven by electrical energy. Aspindle member170 may couple theshaft168 to thetrain124 so that thetrain124 moves when theshaft168 rotates. Sources of frictional load on themotor166 may include the internal friction imparted on themotor166 by the axial load of thespindle170 and the kinetic friction of thetrain element124 sliding on thetrain track element125. As described in more detail below, the friction load on the motor may be substantially reduced to permit themotor166 to consistently rotates even at low torque levels.
• In some embodiments, the control system for thedevice100 may comprise a plurality of ICs including apower supply IC172, a microcontroller174, anamplifier176, amemory IC178, a plurality of high side or low side switches, a plurality ofreverse protection diodes182, or other. TheICs172,174,176,178, and182 may be surface mounted or through-hole mounted to aPCB184 disposed within theinternal space164.
• In this embodiment, thepower supply IC172 may be electrically coupled to the input terminals of theDC motor166 and may supply a DC voltage waveform having a variable duty cycle. The microcontroller174 may generate a control signal to control the duty cycle, wherein thetrain124 moves in response to the rotation of themotor166. Thedevice100 may be powered by a DC or an AC power supply. As shown, the device receives power frombatteries184 so that the device can be conveniently portable. Thebatteries184 may be releasably contained within abattery compartment186 located on the bottom of thebase portion112. Thebattery compartment186 may contain abattery cover188 that may be removed to access thebatteries184. Thebattery cover188 may be removed by releasing a moldedspring snap190 closure. In other embodiments, thebattery cover188 may be releasably mounted to thebattery compartment186 by other means, such as a screw or a rotatable locking mechanism. If an AC power source is used, thedevice100 may include an AC/DC adapter or a rectifier circuit to provide power to the DC motor.
• Thepower supply IC172 ofFIG. 2 may generate waveforms that include a pulse-width-modulation (PWM) circuit, a pulse-density-modulation (PDM) circuit or a pulse-frequency-modulation (PFM) circuit to generate the voltage waveform to control the rotational speed and direction of themotor166. In this embodiment, the power supply IC generates a PWM waveform to control the rotational speed and direction of theDC motor166. It should be understood that, in other embodiments, the PWM circuit may control the speed of an AC motor by adjusting the frequency of the input voltage. The maximum duty cycle of the waveform may be up to 100 percent duty cycle. For example, the operating duty cycle for the PWM waveform may be between 50 and 100 percent, and the minimum operational duty cycle required to impart movement may be at least 5 percent duty cycle. The minimum duty cycle required may be a function of the friction load on themotor166, which may be substantially reduced as described in more detail below.
• The microcontroller174 may vary the PWM control signal according to a predetermined profile stored in thememory IC178. The microcontroller174 may further vary the PWM control signal in response to an external or internal input. Sources of external input may include therotary selector switch152, the “GO”pushbutton162, or the “Sound Effects”pushbutton164. Other embodiments may include photoelectric sensors or infrared sensors to trigger an input in response to light or motion, respectively. Further sources on inputs may comprising a data interface to receive programming or control signals, to synchronize motion, sound or light with other decoration devices, to allow for communication with an external controller, or otherwise. The data interface may comprise a wireless interface, a serial interface, or an radio frequency interference (RFI). Sources of internal input may include photo cell position data, position based on encoder data or other similar sensor data. In this embodiment, the input data for the position of thetrain124 is monitored by two photocell position sensors192. The photocell position sensor192 motion control may provide positional feedback to the microcontroller174 for stopping thetrain124 at the selectedtrain station108,130,132. Atrigger arm194 aligned with the train may be mounted at the base of thespindle170. Thetrigger arm194 triggers the photo cell position sensors as to the position of thetrain124. A set of the photocell position sensors192 may be mounted proximal to each of the 3train stations108,130, and132. Alternatively, thespindle170 may include a ring with slits or hole formed therein may be used to indicate the position of thetrain124. For example, the ring may have spaced apart slits that are detected as each slit moves past the photocell position sensors192. The location of thetrain124 may be determined by counting the number of slits that have passed the photocell position sensors192.
• Still referring toFIG. 2, thetrain124 may be programmed to stop at any one of the threetrain stations108,130, or132 by setting therotary selector switch152 to the blue, red, or green switch position154-158. Any one of the threetrain stations108,130, or132 may be selected using the rotary selector switch152 (FIG. 1a). Once thetrain station108,130, or132 has been selected, pressing the “GO”pushbutton162 may initiate the motion, sound and light control cycle. For example, pressing the “GO” pushbutton may trigger thetrain124 to accelerate (e.g., over a 90 degree rotation in approximately 3 seconds) up to a fall speed of 5 seconds per clockwise revolution. In this example, thetrain124 may go at least one 360 degree revolution around the base of theornament structure104. Thetrain124 may then decelerate (e.g., over a 90 degree rotation, in approximately 3 seconds) and stop at the selected train station. Setting therotary selector switch152 to switch position yellow160 may provide an approximately 60-second “Grand Tour” train ride including acceleration and deceleration. On the “Grand Tour” the audio output system plays a song, and thelight sources134,136,138,140, and142 turn on/off in a pattern that appears to chase thetrain124.
• In this embodiment, the internallight sources134,136,138,140, and142 include five yellow LEDs placed facing up in the bottom of each of the 5 buildings. For example, threelight sources134,136, and138 are located atSleighbell Center130, onelight source140 is located at Santa'sWorkshop108, and onelight source142 is located atGumdrop Junction132.
• The audio output system may be include the previously mentionedamplifier176 and aspeaker194. In this embodiment, the audio output system includes aninner magnet speaker196 using a Digital-to-Analog-Conversion (DAC) speaker output from aVoice Chip amplifier176.
• The cycles of motion, sound and lights in this embodiment for the programmed stops at Gumdrop Junction132 (switch position blue154), Santa's Workshop108 (switch position red156), and Sleigh Bell Center130 (switch position green158) include a voice generated by the audio output system that announces the selectedtrain station108,130, or132 destination. Also, thecorresponding train station108,130, or132light sources140,134-138, or142, respectively, may flash. In one example, thetrain124 sounds may be generated by the audio output system as thetrain124 accelerates to fall speed. Thetrain124 sounds may continue while thetrain124 is moving. Thetrain124 decelerates and stops after the selectedtrain station108,130, or132 destination is detected 2 times by the photocell position sensor192 that corresponds to the selectedtrain station108,130,132 destination. Thus, in this embodiment, thetrain124 may circle theentire train track125 at least once. Thetrain124 sounds and the voice plays once thetrain124 stops at the selectedtrain station108,130,132 destination. Thelight sources140,134-138, or142 for the respective selectedtrain station108,130,132 destination turn on. All the light sources134-142 cycle at the end of the sound cycle and then turn off.
• The cycle of motion, sound, and lights for the programmed cycle for the Grand Tour/Free Play (switch position yellow160) may have different implementations. In this embodiment, the final train destination may include one or all of threeprogrammable train stations108,130 and132. For example, thefinal train station108,103, or132 includes thetrain station108,130,132 from which the Grand Tour begins. Thetrain124 sounds are generated by the audio output system as thetrain124 accelerates to full speed. Once at full speed, the audio output system plays a song, such as the “Rock Candy Railroad Theme” song. The light sources134-142 turn on/off in a pattern that appears to chase thetrain124. Once the song is finished, the light sources134-142 turn on constant. After the song finishes, thetrain124 decelerates and stops the first time the destination marker is detected by the photocell position sensors192 at thedestination train station108,130, or132. Thetrain124 sounds and the voice announces thetrain station108,130,132 once thetrain124 stops at thedestination train station108,130, or132. All light sources134-142 cycle at the end of the sound and then turn off.
• In the previously described example, during any sound or motion, the trigger inputs154-164 associated to the push buttons162-164 and therotary selector switch152 are disabled. The trigger inputs154-164 may be re-enabled when the cycle of sound, lights and motion stops.
• Referring toFIG. 3, a embodiment of adecoration device300 may have a reduced friction load. Thebody portion314 and thespindle assembly370 may include a plurality of decorative elements similar to the elements inFIGS. 1aand1b. For example, thedecoration device300 may include atrain element124. The sum of the decorative elements may be associated with a holiday season such as Christmas. In addition, thedecoration device300 may include light sources and aselector switch152, similar to thedecoration device100 shown inFIG. 1a.
• The movement in theornament structure304 may be imparted to thetrain124 and thespindle assembly370 by aDC motor366, which may be fixedly coupled to thebase312 of theornament structure304. TheDC motor366 may include anoutput shaft368 that rotates to cause thetrain124 to move relative to thebase312. Thespindle assembly370 and train124 may be releasably coupled to theshaft368, as described in more detail below. The weight of thetrain124 and thespindle assembly370 may be substantially supported by asupport arm302 androller assemblies304. Thesupport arm302 androller assemblies304 may be fixedly connected to thespindle assembly370, and therollers304 may be rotatably coupled to thesupport arms302. Theroller assemblies304 may roll upon atrack assembly325, both of which may comprise a low friction material, such as a polymer (e.g., Polytetrafluoroethylene, Nylon, Polycarbonate, Polybutylene Terephthalate, Polyethylene Terephthalate, Polyetherimide, composites thereof, or the like) that may have a TEFLON coating or a MOLYKOTE coating. Thetrack assembly325 may be fixedly coupled to thebase portion312 of theornament structure304.
• Alternatively, other embodiments of thedecoration device300 do not useroller assemblies304 to provide a reduced friction load on theDC motor366. Rather, thesupport arm302 may include a surface that slidably engages a complementary surface of thetrack assembly325. In such embodiments, the sliding surface of thesupport arm302 may comprise a low friction material, such as a polymer with a low-friction coating (e.g., TEFLON coating or a MOLYKOTE coating), that slidably engages the low friction material of thetrack assembly325. For example, in some embodiments, the kinetic coefficient of friction between the sliding surfaces may be less than 0.5. In certain exemplary embodiments, the kinetic coefficient of friction between the sliding surfaces may be about 0.03 to about 0.4. In other embodiments, the kinetic coefficient of friction between the sliding surfaces may be about 0.03 to about 0.3. In still other embodiments, depending upon the material selection previously described, the kinetic coefficient of friction between the sliding surfaces may be about 0.03 to about 0.2.
• In this embodiment, the weight of thetrain124 and thespindle assembly370 may be substantially supported by the contact of therollers304 and thelow friction track325. As a result, theDC motor366 may be subject to a lower total friction load, thereby permitting the DC motor to rotate in a consistent manner even at substantially low torque levels. The lower total friction load may allow for an even greater reduction in the capacity of thepower supply IC372, thebattery384 capacity as well as a reduction in the size of theDC motor366.
• In some embodiments a DC motor controlled by a PWM circuit may operate at substantially low torque levels. In such circumstances, a high friction load upon the motor may be great enough to stop or stutter the motion of the motor'soutput shaft368. In this embodiment, the friction load on theDC motor366 is substantially reduced due to the low friction engagement between therollers304 and thetrack assembly325, or alternatively, the low friction engagement between the sliding surfaces of thesupport arm302 and thetrack assembly325. Again, the low friction roller engagement or the low friction slidable engagement may each provide a reduced friction load on the DC motor366.In the embodiment shown inFIG. 3, the frictional resistance to the DC motor's366 rotation is substantially reduced, thereby permitting theDC motor366 to operate under control of a PWM circuit even though theDC motor366 may be operating at low torque levels.
• In addition to reducing the kinetic friction, the axial load on theDC motor366 may be reduced (which may reduce the internal friction load of the DC motor366) because the weight of thespindle assembly370 is substantially supported by thetrack assembly325. As described in more detail below, theoutput shaft368 of theDC motor366 may use a spline connection (e.g.,FIG. 4b) to engage thespindle assembly370. In such embodiments, theDC motor366 may drive the rotational movement of thetrain124 without necessarily bearing an axial load from the weight of thespindle assembly370.
• Other means to reduce drive line friction include TEFLON or MOLYKOTE coated bushing and mechanisms that suspend the movable component such that it does slide against any other component of the ornament. In one example, a wire coupled to the motor shaft projects upwardly and outwardly through a circumferential slit in the ornament housing. The movable component is disposed on the distal end of the wire such that as the shaft rotates the movable component is articulated substantially without bringing the wire into contact with the ornament housing.
• Referring toFIG. 4a, thedecoration device300 may include aremovable assembly370. Thespindle assembly370 may be removed from theornament structure304 by sliding thespindle assembly370 away from theshaft368 in a substantially axial direction (e.g., substantially upward in the view shown inFIG. 4a). An alternate design of aspindle structure470 may be releasably coupled to theornament structure304 in place of thefirst spindle assembly370. For example, thefirst spindle assembly370 may include a first theme associated with the Christmas holiday season, and thealternate spindle assembly470 may include a second theme associated with a different holiday (e.g., New Year's Eve or Valentine's day), season (e.g., the Winter season), or event (e.g., a birthday celebration). In this embodiments, thealternate spindle assembly470 may be installed by sliding it onto theshaft368 in a substantially axial downward direction relative to theornament structure304.
• Thealternate spindle assembly470 may include one or more decorative elements that are configured to resemble patterns, characters, scenes or words that may be associated with a particular season or holiday. In this embodiment, the decorative elements onspindle assembly470 include adecorative Christmas tree120, a rockinghorse322, a north pole sign324, a bird with a wool cap andscarf326, a plurality ofChristmas present328, a reindeer in a snow coveredchimney330, and a dancingSanta Claus332. In certain embodiments, the sum of the decorative elements may be associated with the Christmas holiday season so that both thefirst spindle assembly370 and thealternate spindle assembly470 may be displayed interchangeably during the Christmas holiday season. In other embodiments, the decorative elements of thealternative spindle assembly470 may be associated with a different holiday season. For example, a user may display thefirst spindle assembly370 during the Christmas holiday season, and then the user may replace thefirst spindle assembly370 with thealternate spindle assembly470 that could be associated with the New Year's Eve holiday. Thus thedecoration device300 is readily adapted for use during multiple holidays, seasons, or events.
• Referring toFIG. 4b, aspline assembly400 may releasably couple thespindle assemblies370 and470 to theshaft368. Thespline assembly400 includes amale spline402 fixedly coupled to the outer diameter of theshaft368 and afemale spline404 fixedly coupled to the inner diameter of the end of thespindle assembly370. It should be understood that thealternate spindle assembly470 include a similarfemale spline404. Theinternal spline members406 and theexternal spline members408 are sized so as to allow the male andfemale splines402 and404 to mate with one another, thereby releasably coupling thespindle assembly370 or470 to theornament structure304. In alternate embodiments, the coupling mechanism may be otherwise and may include mating assemblies such as square, hexagonal, or threaded couplings.
• Because the spline connection causes themotor shaft368 to be rotationally stationary relative to thespindle assembly370 or470, theDC motor366 may cause thespindle assembly370 or470 to rotate. However, because the spline connection causes themotor shaft368 to be axially slidable relative to thespindle assembly370 or470. TheDC motor366 does not necessarily bear an axial weight load from thespindle assembly370 or470 (bearing upon the track assembly325), which may reduce the internal friction imposed upon theDC motor366.
• Referring toFIG. 5, an alternate embodiment of thedecoration device500 is shown wherein theoutput shaft568 of themotor566 is coupled to thespindle assembly570 via agear system510. In this embodiment. thegear system510 includesgears502,504,506, and508. Thegear502 is fixedly coupled to theshaft568 and may impart movement viagear504,gear506, andgear508 to at least a portion of thedecoration device500. Thegear508 may be coupled to at least a portion of a spline assembly (refer, for example, to thespline assembly400 ofFIG. 4b) so that the spindle assembly is removable. The motion imparted by themotor566 through theshaft568 and the gears502-508 may rotate thespindle assembly570 at a speed that is proportionally reduced from the speed of rotation of the motor'soutput shaft568.
• Similar to the embodiment ofFIG. 3, this embodiment may provide a reduced friction load on themotor566. For example, theshaft568 of themotor566 may bear a substantially reduced axial load from the weight of thespindle assembly570, which bears upon a track assembly (similar to thetrack assembly325 ofFIG. 3). Further, thespindle assembly570 may include rollers or low friction sliding surfaces to reduce the rotational friction load upon themotor566, as previously described in connection withFIG. 3. This may allow for the use of asmaller motor566, and a reduction in the capacity of thepower supply IC372 and thebattery384. Moreover, the reduced friction load on theDC motor566 may permit theDC motor566 to operate at low torque levels.
• FIG. 6 shows an embodiment of acontroller600 that may provide controlled voltage or current to set a decoration device (e.g.,device100,300, or500) into motion. Thecontroller600 may include pulse width modulator (PWM)circuits610a,610ab,610ac, and610an, each of which can output a controlled voltage waveform capable of driving a DC motor620 (which may be similar to theDC motors166,366, and566 in the previously described embodiments) that is coupled to PWM output ports,615a,615b,615c, and615n, respectively. In some embodiments, other types of loads may be connected to one or more of the ports615a-615n. For example, loads such as a light string, LED's, or audio output devices may be connected to the ports615a-615nand driven by the corresponding PWM circuits610a-615n. Also, in other embodiments, the decoration device may comprise an AC motor, and one or more PWM circuits may control the speed of the AC motor by adjusting the frequency of the supply voltage.
• In this example,PWM circuit610ais connected to theDC motor620, which may be coupled to move a figurine or decorative element (e.g., a train element124), as described, for example, in connection with thedecoration devices100,300, and500. ThePWM610amay be operated to supply a controlled voltage waveform to cause theDC motor620 to output a controlled amount of electromagnetic torque to theshaft625. An exemplary implementation of a PWM circuit will be described in detail below.
• For example, thePWM circuit610amay include circuitry to generate a square wave voltage waveform by switching its output terminals between a high-side supply rail voltage and a low-side supply rail voltage at a predetermined switching frequency. The voltage waveform can be defined by a voltage applied to the terminals and a duty cycle. In one example, thePWM circuit610amay output a waveform with a 50% duty cycle, which corresponds to thePWM circuit610aconnecting its output terminal to the high side supply rail voltage for 50% of the period of the waveform, and then connecting its output terminal to the low side supply rail voltage for the remainder of the period. According to this example, the average voltage output by thePWM circuit610awould be approximately 50% of the high side supply rail voltage. At an appropriate frequency range, theDC motor620 will perceive the output voltage as an average of the on and off voltages over the time period applied to theDC motor620 and may be controlled so as to achieve a desired rotational speed. The duty cycle may be varied to obtain a corresponding variation in the rotational speed, and thus obtain a controlled motion profile for thedevices100,300, and500. For example, thePWM circuit610amay also produce voltage waveforms of 30% duty cycle, 80% duty cycle or 100% duty cycle. Each PWM circuit610a-610nmay be set to operate at the same or different switching frequencies. The frequency modulation range is typically between 100 Hz to 5 kHz. Depending on the motor selection, the frequency modulation range may be higher, for example, between 5 kHz and 1 MHz.
• In alternative embodiments, the PWM circuits610a-610ncan be modified to operate using other suitable modulation techniques, such as pulse frequency modulation (PFM), pulse amplitude modulation (PAM), or hysteretic (bang-bang) control. For bi-polar power supply rails, a three-level voltage (positive, zero, negative) modulation may be employed, which may have benefits including reduced harmonic content and increased efficiency. In addition, other methods may be implemented in combination with the selected modulation techniques, such as current-mode control, regenerative braking (energy recovery), and the like.
• In response to the control signals from thecontroller600, thePWM610acan increase and decrease the speed of theDC motor620 by respectively increasing and decreasing the duty cycle of the output waveform. This enables theDC motor620 to provide different amounts of torque for thedevices100,300, and500 of different physical sizes.
• For example, thePWM circuit610amay be used to operate theDC motor620 to move the decorative elements as described in connection with thedecoration devices100,300, and500, at a constant speed, at a randomly determined speed, or at a speed according to a predetermined speed profile (e.g., so as to accelerate and/or decelerate at a certain rate for a predetermined period of time, or to move at a first speed during a first period of time and then move at a second speed during a second period of time). In an alternative embodiment, the controller may operate the DC motor according to a randomly varying profile to cause the motion of for thedevices100,300, and500 to vary in unpredictable ways. In one embodiment, the system can be used to impart movement to a decorative element such as the train element124 (FIG. 1a,3, or5). The speed of thetrain124 may increase, then decrease as it approaches amodel train station108,130, or132 (e.g.,FIGS. 1aand1b) or a switch point in the train tracks. Optionally, thePWM610avoltage may be used to modulate the light intensity of a light on the train, or lights on the train tracks.
• In another example, thePWM610acan be connected to a decorative light or light string in order to vary the operation time, operation sequence, or brightness.
• Amicrocontroller630 can be used to monitor and control the operation of thePWMs610a,610b,610c,610n. Themicrocontroller630 can include a microprocessor and related circuitry for controlling the functions and components of thecontroller600. Themicrocontroller630 can execute software instructions associated with the operation of the components of thecontroller600 and the software instructions for thedecoration device100,300, or500. The software instructions can be stored in amemory650 which is connected to themicrocontroller630. For example, thememory650 may include read only memory (ROM), random access memory (RAM), magnetic or optical storage, or a combination thereof.
• Apower supply640 provides operating DC voltages such as 12V, 5V, 3.3V, 2.5V, 1.8V, 1.5V, and 1.2V, to the various components within thedevice manager600, and it may also provide differential voltage signals. Apower input circuit645 receives power from outside thedevice manager600. If thepower input circuit645 receives an alternating current (AC) signal, then it can include a transformer and rectifier to convert the AC signal to a direct current (DC) signal. Thepower input circuit645 may include protection circuitry, over-voltage protection such as a fuse, and filtering.
• Adata interface660 is connected to thecontroller630. The data interface660 can be used for uploading or downloading software instructions to and from thecontroller630 and thememory650, or for operating thedevice manager600. The data interface660 can receive data via radio frequency (RF) wireless transmission such as Bluetooth, infrared data transmission, a universal serial bus (USB) port, a keypad or keyboard. The data interface660 can also include sensors for sound and light such that the controller may activate or deactivate one or more of thePWMs610a,610b,610c,610nbased on the amount of input sound vibrations, such as a handclap or music, and the amount of visible light, such as sunlight. Adisplay adapter670 is connected to themicrocontroller630 and may be used to send information to a display device such as a CRT display, flat panel display, LCD or LED display, or similar display device. Themicrocontroller630 can be connected to anamplifier680 that can output a signal to aspeaker685 to provide sound. Astatus indicator690 is connected to themicrocontroller630. Thestatus indicator690 may be one or several lights or light emitting diodes (LED) and can represent the present operating status of thecontroller600.
• Referring toFIG. 7, showing a circuit diagram of an exemplarymotor control circuit700 that includes a DC motor710 (e.g., similar to theDC motors166,366, and566 described in previous embodiments). In this example, themotor control circuit700 has an H-bridge circuit topology. Themotor control circuit700 includesswitches740,742,744,746 which are connected to reverseprotection diodes730,732,734,736, respectively.
• The load current paths in thePWM circuits610aare provided by the circuit connections as follows. Themotor control circuit700 is coupled to a source of power via apositive rail node750 and anegative rail node756. High side switches720,724 each have a terminal coupled to thepositive rail node750. Low side switches722,726 each have a terminal coupled to thenegative rail node756.High side switch720 andlow side switch722 each have a terminal coupled to anoutput node752 which is also connected to one terminal of theDC motor710.High side switch724 andlow side switch726 each have a terminal coupled to anoutput node754, which is also connected to a second terminal of theDC motor710.
• Theswitches720,722,724,726 are individually connected to controlsignals740,742,744,746 as follows. Control signals740,742,744,746 are each coupled to a control input (for example, gate or base) of theswitch720,722,724,726, respectively. For purposes of this disclosure, the control signals,740,742,744,746 may be in either a high state or a low state. In one state, the corresponding switch is typically operated in a non-conducting (off) state. In the other state, a corresponding switch is operated in a conducting (saturated on) state.
• In one exemplary mode of operation, forward motion of theDC motor710 may be accomplished as follows. The PWM sends control signals740,746 to turn on switches720,726. In this condition, the terminal of theDC motor710 connected tooutput node752 receives the high side voltage frompositive rail node750, and the terminal connected tooutput node754 receives the low side voltage fromnegative rail node756, and the motor rotates.
• In another exemplary mode of operation, reverse motion of theDC motor710 may be accomplished in a similar manner. The PWM sends control signals742,744 to turn on switches722,724. In this condition, the terminal ofDC motor710 connected tooutput node754 receives the high side voltage frompositive rail node750, and the terminal connected tooutput node752 receives the low side voltage fromnegative rail node756, and the motor rotates in reverse.
• TheDC motor710 may be decelerated from motion, or braked, in two exemplary modes. In the first exemplary mode, the PWM turns onswitches720,724 while keepingswitches722,726 turned off. This short circuits theDC motor710 and causes it to act like a generator which causes the motor to decelerate or brake. In a second exemplary mode, the PWM can sendcontrol signals742,746 to close theswitches722,726 which will also short circuit theDC motor710 and it will decelerate or brake.
• In an alternative embodiment, theswitches740,742,744,746 may be implemented using other suitable switching devices, such as MOSFETs, JFETs, BJTs, IGBTs, or combinations of transistors, such as Darlington pairs, for example. The diodes760,762,764,766 may be discrete or directly integrated with the switches. Auxiliary circuitry (not shown) may be added to themotor control circuit700 to provide, for example, gate drive, biasing, and protection as needed to operate the switches according to various embodiments.
• In various embodiments, thePWM circuit610amay be implemented using various circuit topologies. For example, thePWM circuit610amay be any suitable dc-dc converter topology, including: full-bridge, half-bridge, buck, boost, buck-boost, Cuk, Cepic, flyback. The converter may have none or more stages, including power-factor corrected inputs or transformer-isolated inputs with appropriate rectification. The power source may be received from AC and or DC sources, including batteries.
• Referring toFIG. 8, showing another embodiment of acontroller800. Thecontroller800 includes amicrocontroller circuit810 and andevice circuit820. Themicrocontroller circuit810 includes such components as aPWM830, amicrocontroller850, amemory855, and anencoder860. Thedecoration device circuit820, which for example may contain the previously described train element124 (refer toFIG. 1a,3, or5), includes such components as aDC motor840, adecoder870, amicroprocessor880, and it may include accessories such as LED's882,lights884, awhistle886, and asmokestack888.
• In one implementation, thePWM830 may be operated to power theDC motor840. Themicrocontroller850 can retrieve voltage profile information from thememory855 and send the information to thePWM830 which can generate the voltage waveforms to operate the DC motor.
• In another implementation, thePWM830 may be operated to communicate encoded information using theencoder850 in addition to powering theDC motor840. For example, thePWM830 switching frequency may be alternately set to one of two selected frequencies, such as 110 kHz and 130 kHz, to encode information using, for example, a frequency-shift-keying (FSK) technique. Other similar encoding methods, such as amplitude-shift-keying (ASK) and phase-shift-keying (PSK), may be used to encode data at a fraction of the switching frequency while providing a controlled waveform to operate theDC motor840.
• The encoded information from thePWM830 can be decoded bydecoder870 and sent to themicroprocessor880. In one implementation, themicroprocessor880 can use the decoded information to take a predetermined action, such as turning on or off a light, or operating a valve or relay. For the exemplarydecoration device circuit820, themicroprocessor880 can operate the LED's882,lights884,whistle886, and thesmokestack880.
• In other embodiments, two or more decoration devices (or a single decoration device having two ormore spindle assemblies370 with decorative elements thereon) may be operated in synchronism using controlled variations in the average voltage in the PWM waveform and/or information encoded in the modulation. The encoded information may include commands, data (e.g., audio, video), status, control, programming, or other information that may be used in the operating of the device, or system of devices having at least one DC motor.
• Referring toFIG. 9, showing a flowchart of themicrocontroller850 tasks and a flowchart of themicroprocessor880 tasks that represent the data transfer between themicrocontroller circuit810 and thedecoration device circuit820. Instep910, themicrocontroller850 retrieves the voltage profile and accessory operation data from thememory855. Atstep920,microcontroller850 sends the voltage profile data to thePWM830, and sends the accessory data to theencoder860 to be encoded by adjusting the switching frequency or by a similar method. Atstep930, thePWM830 receives and modulates the data from themicrocontroller850 and theencoder860 and outputs it to thedecoration device circuit820.
• Instep940, thedecoration device circuit820 sends an identifying signal to thePWM830 and receives the data instep950. Atstep960, thedecoder870 decodes the signal and sends the data to themicroprocessor880 instep970. If themicroprocessor880 finds no accessory data present instep980, an identifying signal is sent to thePWM830 to restart the procedure. If themicroprocessor880 finds accessory data instep980, it activates the required accessories instep990, for example a previously described whistle or lights, and then sends a confirmation signal toPWM830 instep1000 and the process repeats.
• In other embodiments, the decoration device may comprise a linear actuator that provides a substantially linear motion path for the movable ornament. The linear actuator may be substantially smaller and more durable than a DC motor. Also, the linear actuator may be generally more quiet than an AC or DC motor having a gear system coupled thereto. In one example, one or more PWM circuits may control the motion of a solenoid actuator to provide a substantially smooth, bidirectional linear motion for the movable ornament. In such circumstances, the linear actuator may directly engage (without a spindle assembly) or otherwise cause the movable ornament (e.g., thetrain element124 or the like) to travel in a linear path between two or more stop locations (e.g., thetrain stations108,130, or132 arranged along the linear path). Alternatively, the AC or DC motor may drive the linear motion of the movable ornament using a linkage apparatus to convert the rotary motion into linear motion and using, in some embodiments, a gear system that reduces the rotational speed from the motor.
• As noted above, use of PWM controlled AC or DC motors may substantially reduce or eliminate the gearing needed to generate the necessary torque for a given ornament design. In certain embodiments, the gear system may comprise as few as four, three or two gears.
• A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Claims (20)

1. An ornament, comprising:

a base;

a mobile decorative element coupled an intermediate assembly so that the mobile decorative element coupled an intermediate assembly so that moves relative to a base is movable relative to the base;

an electrically powered actuator mechanically coupled to the intermediate assembly such that actuation of the electrically powered actuator causes the mobile decorative element to move relative to the base;

a pulse width modulation controller to drive the electrically powered actuator, the pulse width modulation controller providing a pulse-width-modulated waveform that is output to the electrically powered actuator; and

low friction interface means for supporting the mobile decorative element relative to the base.

2. The ornament ofclaim 1, wherein at least the base and the mobile decorative element have appearances associated with Christmas, the ornament further comprising one or more light sources coupled to the base, the light sources emitting light when the mobile decorative element to moves relative to the base.

3. The ornament ofclaim 1, wherein the pulse width modulation controller is programmed to drive actuation of the electrically powered actuator according to a predetermined speed profile that varies with time.

4. The ornament ofclaim 3, wherein the predetermined speed profile that varies with time comprises an acceleration over a predetermined period of time, a generally constant actuation over a predetermined period of time, and deceleration over a predetermined period of time.

5. The ornament ofclaim 1, wherein the mobile decorative element has a first surface that is at least partially supported by an opposing second surface of the base.

6. The ornament ofclaim 5, wherein the low friction interface means comprises an interface between the first surface and the second surface characterized by a kinetic coefficient of friction of less than about 0.3.

7. The ornament ofclaim 5, wherein the kinetic coefficient of friction is about 0.03 to about 0.2.

8. The ornament ofclaim 5, wherein the low friction interface means comprises a slidable engagement between the first surface and the second surfaces, the first and second surfaces comprises one or more polymer materials.

9. The ornament ofclaim 8, wherein the first surface and the opposing second surface have a low friction interface to limit the friction load on the electrically powered actuator, the low friction interface being characterized by a kinetic coefficient of friction between the first and second surfaces of less than about 0.2.

10. The ornament ofclaim 8, wherein the electrically powered actuator comprises a motor having an output shaft such that rotation of the output shaft causes the mobile decorative element to move relative to the base.

11. The ornament ofclaim 10, wherein the output shaft of the motor is mechanically coupled to the intermediate assembly via a gear system that causes the mobile decorative element to rotate at a rate less than the rotation of the output shaft.

12. The device ofclaim 1, wherein the pulse width modulation controller outputs a pulse-width-modulated waveform having a duty cycle that is controllably adjusted to obtain a corresponding adjustment to the actuation of the electrically powered actuator.

13. A holiday ornament device for providing a decorative appearance associated with a holiday, comprising:

a base;

a mobile decorative element that is movable relative to a base;

an electrically powered actuator coupled to the mobile decorative element such that actuation of the electrically powered actuator causes the mobile decorative element to move relative to the base;

a pulse width modulation controller to drive the electrically powered actuator; and

a slidable surface interface between the mobile decorative element and the base so as to support the mobile decorative element relative to the base.

14. The holiday ornament device ofclaim 13, wherein at least the base and the mobile decorative element have appearances associated with Christmas, the holiday ornament device further comprising one or more light sources coupled to the base, the light sources emitting light when the mobile decorative element to moves relative to the base.

15. The holiday ornament device ofclaim 13, wherein the pulse width modulation controller is programmed to drive actuation of the electrically powered actuator according to a predetermined speed profile that varies with time.

16. The holiday ornament device ofclaim 15, wherein the predetermined speed profile that varies with time comprises an acceleration over a predetermined period of time, a generally constant actuation over a predetermined period of time, and deceleration over a predetermined period of time.

17. The ornament ofclaim 13, wherein the slidable surface interface comprises a first surface of the mobile decorative element that is at least partially supported by an opposing second surface of the base.

18. The ornament ofclaim 17, wherein the low friction interface means comprises an interface between the first surface and the second surface characterized by a kinetic coefficient of friction of less than about 0.3.

19. The ornament ofclaim 13, wherein the electrically powered actuator comprises a motor having an output shaft such that rotation of the output shaft causes the mobile decorative element to move relative to the base, wherein the output shaft of the motor is mechanically coupled to the mobile decorative element via a gear system.

20. The device ofclaim 13, wherein the mobile decorative element is coupled to an intermediate assembly that is mechanically mounted to the electrically powered actuator.

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