Pulse Width Modulation Drive and Method for Ornaments with Moveable Components

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.

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 of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 5 , wherein the kinetic coefficient of friction is about 0.03 to about 0.2.  
   
   
       8 . The ornament of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 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 of  claim 13 , wherein the mobile decorative element is coupled to an intermediate assembly that is mechanically mounted to the electrically powered actuator.