Abstract:
In response to user interaction, a signal is generated from a control element of a sample diffuser assembly. The sample diffuser assembly comprises a sample container, wherein the sample container is configured to receive a sample to be diffused; a motor operative to assist in diffusing the sample at a selectable transformation rate; a light source, wherein the light source comprises an AC lamp; and control circuitry operatively coupled to the motor and the light source. A set of signals is generated, via the control circuitry in response to the signal generated by the control element, wherein the set of signals simultaneously control the light intensity of the AC lamp based on the transformation rate produced by the motor to diffuse the sample in the sample container.

Description:
FIELD 
       [0001]    The present application generally relates to sample diffusion techniques and, more particularly, to sample diffusion techniques employed in conjunction with additional sensory stimulus control techniques. 
       BACKGROUND 
       [0002]    An aerial diffusion device, commonly known as a diffuser, is a device that diffuses a sample into the surrounding air. In one example, the sample is oil such as, e.g., fragrance oil, and the oil is diffusively delivered into the surrounding air as a fine mist or spray. Examples of diffusers include ultrasonic diffusers that vaporize the sample via vibration, evaporative diffusers that vaporize a sample by directing air through a filter where the sample is resting, heat diffusers that utilize a heat source to diffuse the sample, and nebulizing diffusers. Nebulizing diffusers work by using a pressurized air stream generated by an air pump with a specially designed nozzle. Advantageously, the rate of evaporation of a nebulizing diffuser is highly accelerated and occurs almost instantly. The air pump and nozzle, along with the shape of the diffuser bulb that holds the sample, cause the sample to atomize into a fine spray or mist for delivery into the surrounding air. 
         [0003]    Fragrance diffusers have become very popular for use in homes and offices in order to deliver an olfactory stimulus in the form of a desired scent into a particular room or area of the home or office. Attempts have been made to provide a secondary sensory stimulus in conjunction with the olfactory stimulus provided by the fragrance diffuser. However, prior art attempts at such multiple sensory stimuli have experienced difficulties in coordinating the multiple devices that respectively provide the multiple sensory stimuli. 
       SUMMARY 
       [0004]    Embodiments of the invention provide sample diffusion techniques employed in conjunction with synchronized lamp brightness control techniques. 
         [0005]    By way of example only, in one illustrative embodiment, a sample diffuser apparatus comprises a sample container, a motor, a light source, and a control system. The sample container is configured to receive a sample to be diffused. The motor is operative to assist in diffusing the sample at a selectable transformation rate. The light source comprises an alternating current (AC) lamp. The control system is operatively coupled to the motor and the light source, wherein the control system comprises: a switch assembly comprising a potentiometer, wherein the potentiometer provides a voltage responsive to user interaction; and control circuitry operatively coupled to the switch assembly, the control circuitry configured to enable synchronous control of the transformation rate of the sample in the sample container and an intensity of light emitted by the AC lamp based on the voltage provided by the potentiometer. 
         [0006]    The control circuitry, in an illustrative embodiment, comprises: lamp driver circuitry operatively coupled to the AC lamp; motor driver circuitry operatively coupled to the motor; and a microcontroller operatively coupled to the lamp driver circuitry and the motor driver circuitry, the microcontroller programmed to generate a first signal output to the motor driver circuitry and a second signal output to the lamp driver circuitry, wherein the second signal relates to the first signal to simultaneously control the intensity of the light based on the transformation rate. 
         [0007]    In a further illustrative embodiment, a method for controlling diffusion of a sample comprises the following steps. In response to user interaction, a signal is generated from a control element of a sample diffuser assembly. The sample diffuser assembly comprises a sample container, wherein the sample container is configured to receive a sample to be diffused; a motor operative to assist in diffusing the sample at a selectable transformation rate; a light source, wherein the light source comprises an AC lamp; and control circuitry operatively coupled to the motor and the light source. A set of signals is generated, via the control circuitry in response to the signal generated by the control element, wherein the set of signals simultaneously control the light intensity of the AC lamp based on the transformation rate produced by the motor to diffuse the sample in the sample container. 
         [0008]    Advantageously, in one example, embodiments provide a fragrance diffusion system for controlling the rate at which a fragrance is diffused and the intensity of a light bulb, in a simultaneous and synchronous fashion, within an environment in which the diffuser system is deployed. 
         [0009]    These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  illustrates a perspective view of a diffuser assembly, according to an embodiment of the invention. 
           [0011]      FIG. 2  is a top level block diagram of components of a diffuser assembly, according to an embodiment of the invention. 
           [0012]      FIG. 3  is a more detailed level block diagram illustrating diffuser assembly control circuitry, according to an embodiment of the invention. 
           [0013]      FIGS. 4A and 4B  are schematic diagrams illustrating diffuser assembly control circuitry, according to an embodiment of the invention. 
           [0014]      FIGS. 5A through 5C  illustrate example signal waveforms associated with a diffuser assembly, according to an embodiment of the invention. 
           [0015]      FIG. 6  illustrates turn on delays for potentiometer settings, according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Embodiments of the invention will be described herein with reference to a diffuser assembly having synchronous control of the rate at which a fragrance is diffused into a room and the intensity of the light emitted by an associated lamp. The diffuser assembly enables a user to selectively adjust the diffusion intensity ranging between a low level and a high level. A low diffusion intensity corresponds to a mild or subtle scent being introduced into the surrounding area, while a high diffusion level corresponds to a stronger scent being introduced. In various illustrative embodiments, the range can include continuous or discrete intensity levels between the low and high levels. A lamp in the diffuser assembly provides a visual indication of the adjustment of the diffusion intensity. That is, the brighter the light emitted by the lamp, the higher the diffusion intensity. Thus, a user can associate the light intensity output by the diffuser assembly with the diffusion intensity. The diffuser assembly further comprises electrical circuitry that functions to synchronously control the brightness of the lamp with the diffusion intensity. In one illustrative embodiment, the lamp is an incandescent light bulb, and the diffuser is a nebulizing diffuser comprising a glass bulb with a glass stopper into which fragrance oil is deposited. 
         [0017]    While illustrative embodiments are described herein with respect to a sample being fragrance oil, it is to be appreciated that the inventive teachings are more broadly applicable to other types of diffusable oils including, but not limited to, essential oils, aromatic oils, and perfume oils. 
         [0018]      FIG. 1  illustrates a view of a diffuser assembly  100  showing an example of the locations in which a control element (shown at least in part in  FIG. 1  as user control  110 ), glass bulb  106 , glass top  108 , which is placed on top of the glass bulb, and lamp  104  may be located. In the exemplary illustration of  FIG. 1 , user control  110  is located on top of diffuser platform  102  and closer to a first side of diffuser platform  102 . Glass bulb  106 , into which fragrance oil (or other sample) is deposited, is located in proximity to the center of diffuser platform  102 . The glass bulb may be more generally referred to as a sample container. Lamp  104 , which may be a decorative type of bulb, is shown positioned closer to a second side of diffuser platform  102 . However, such a placement is merely exemplary. Alternative placements of lamp  104 , as well as the other components of diffuser assembly  100 , are contemplated. It is to be appreciated that circuitry for controlling the diffuser and light components on top of the platform  102  are contained inside diffuser platform  102 . 
         [0019]    In one embodiment, lamp  104  is directly connected to an alternating current (AC) source. For example, lamp  104  may be an incandescent bulb, such as a decorative Edison-type incandescent bulb. In one embodiment, lamp  104  is rated at 40 Watts (W). However, the type of lamp and wattage rating should not be considered limiting. 
         [0020]    As further shown in  FIG. 1 , electrical cord  112  (with a typical AC male plug that is not expressly shown) is supplied to connect AC power to diffuser assembly  100 . The AC power supplied depends on the country in which diffuser assembly  100  will be used. Thus, alternative embodiments of diffuser assembly  100  are respectively configured to operate with the AC voltage level and frequency of the country in which they will be used. For example, AC power in the United States is typically provided between 110 AC Volts (VAC) and 120 VAC at 60 hertz (Hz), while France and other European countries typically operate between 220 VAC and 240 VAC at 50 Hz. Also contemplated with one or more alternative embodiments is a diffuser assembly  100  that operates in dual (50 Hz/60 Hz) environments and/or environments using other standard voltage levels and frequencies. It is to be appreciated that diffuser assembly  100  can be specifically designed and/or customized to provide its synchronous control functionalities for diffusion intensity and lamp intensity for the AC line power environment with which the diffuser assembly needs to operate. In one illustrative embodiment, as will be described herein, the diffuser assembly is configured to operate in a voltage range from 90 VAC up to 260 VAC, inclusive, and operate on frequencies of 50 Hz or 60 Hz. 
         [0021]      FIG. 2  illustrates a top level block diagram of components (collectively depicted as reference numeral  200 ) of a diffuser assembly, such as diffuser assembly  100  shown in  FIG. 1 , according to an illustrative embodiment. As shown, components  200  comprise switch assembly  210 , AC line cord  212 , diffuser printed circuit board (PCB) assembly  216 , lamp  204 , and motor  214 . Components  200  may additionally comprise switch  222  operative to connect or disconnect the AC power. Switch  222  may be incorporated into switch assembly  210 , or may be located separate from switch assembly  210 . As discussed above, lamp  204  is directly connected to an AC source. In one embodiment, lamp  204  is an incandescent lamp. For example, lamp  204  may be an Edison-type decorative lamp having a rated wattage of 40 watts, although other types of incandescent lamps and other wattage ratings (more generally, any lamp that operates directly on AC power) are also contemplated. Motor  214  is coupled to the base of glass bulb  106  ( FIG. 1 ) and is operative to control the diffusion rate, also referred to herein as transformation rate, of fragrance oil deposited within glass bulb  106 . In one embodiment where the diffuser is a nebulizing diffuser, motor  214  is an air pump type motor. Switch assembly  210  provides both an on/off switch control and a potentiometer for synchronous and simultaneous control of motor  214  and the intensity of lamp  204 , as will be explained in further detail below. 
         [0022]    PCB assembly  216  includes analog circuitry  218  and digital control circuitry  220 . Analog circuitry  218  operates to supply AC power to lamp  204 , and convert the AC line power to a regulated direct current (DC) low voltage supply for use in digital control circuitry  220 . 
         [0023]    The components shown in  FIG. 2  may be considered a control system for lamp  204  and motor  214 . 
         [0024]      FIG. 3  illustrates a more detailed level block diagram (with the components collectively depicted by reference numeral  300 ). More particularly, various components shown in  FIG. 3  may be considered components that are part of PCB assembly  216  ( FIG. 2 ). Also, interface connections of PCB assembly  216  with lamp  304 , motor  314 , and switch assembly  310  are shown in  FIG. 3 . Thus, as shown, PCB assembly  216  comprises AC input protection circuitry  330 , AC-DC regulated power supply circuitry  332 , lamp driver circuitry  334 , motor drive circuitry  336 , and pulse width modulator (PWM) generator circuitry  338 . 
         [0025]    Input protection circuitry  330  interfaces the AC input line voltage with the remainder of the electronic components providing both short circuit protection as well as input transient voltage spike protection. The AC-DC regulated power supply  332  converts the input AC line voltage to a regulated DC low voltage supply for use by lamp driver circuitry  334 , motor driver circuitry  336 , PWM generator circuitry  338 , and switch assembly  310 . PWM generator circuitry  338  provides control signals to lamp driver circuitry  334  and motor driver circuitry  336 , which control the intensity or brightness of lamp  304  and the speed of motor  314 , respectively. The signal output to lamp driver circuitry  334  is related to the signal output to motor driver circuitry  336 , such that a synchronous relationship is established between the transformation rate of the fragrance oil and the intensity of the light emitted by lamp  304 . In one embodiment, the intensity of the light emitted by lamp  304  is proportional to the transformation rate of the fragrance oil. 
         [0026]    In one embodiment, the transformation rate of the fragrance oil is also proportional to the speed of motor  314 . As mentioned above, the intensity of light emitted from lamp  304  and the transformation rate of the fragrance oil, or speed of motor  314 , are controlled by PWM generator circuitry  338 . In one embodiment, PWM generator circuitry  338  provides controlled pulse width signals, each half cycle of the AC input, to lamp driver circuitry  334  and motor driver circuitry  336 . Each of the pulse width signals are characterized by a start time delayed from the zero crossover of the AC input signal, and an end time at the following zero crossover of the AC input signal. The delay of the start time of the pulse may be controlled by the user via switch assembly  310 . The width of the pulse width is directly related to the intensity of the light emitted from lamp  304  and the speed of motor  314 . Specifically, a wider pulse width, resulting from a shorter start time delay, results in a higher light intensity and higher motor speed as compared to a narrower pulse width resulting from a longer start time delay. 
         [0027]    It is to be appreciated that the pulse width of the signal output to motor  314  may be insufficient to cause motor  314  to start. Accordingly, in one embodiment, PWM generator circuitry  338  is pre-programmed to ensure that when the diffuser assembly is turned on, and switch assembly  310  is asserting a minimum pulse width, the pulse to motor driver  336  is of sufficient width to start the motor (which is readily determined during design of the control circuitry based on the operating specifications of the motor being used). 
         [0028]    Recall that in  FIG. 1 , a control element, such as user control  110 , is provided on diffuser assembly  100  for controlling both the intensity of the lamp and the diffusion rate of the fragrance oil. In one embodiment, the control element may be coupled to and/or part of switch assembly  310 , such that manipulating the control element controls the operation of lamp  304  and motor  314 . For instance, the control element is operative to turn both lamp  304  and motor  314  on and/or off. Additionally, manipulating the control element adjusts the start time delay of the pulse widths controlling lamp driver  334  and motor driver  336 . Accordingly, manipulating the control element simultaneously and synchronously affects the intensity of light emitted from lamp  304  and the speed of motor  314 . 
         [0029]      FIGS. 4A and 4B  combined form the complete schematic diagram for the control circuit of an exemplary diffuser, e.g., diffuser assembly  100 . With reference to  FIG. 4A , the schematic illustrates a portion  400  of the control circuit related to AC input protection  330  and the AC-DC regulated power supply  332  of  FIG. 3 . The AC input voltage connected to terminals X 1 - 1  and X 2 - 1  may range from 90 VAC up to 260 VAC, inclusive, and may operate on frequencies of 50 Hz or 60 Hz. Components L 1  through R 9  referenced in  FIG. 4A  combine to form a power supply that tracks the line voltage to create a regulated 5 VDC voltage used by the circuitry shown in  FIG. 4B . In addition, the AC voltage, AC-HI and AC-LOW, is used to supply power to the lamp and to provide a reference to determine the line voltage zero crossing point. 
         [0030]    The input protection circuit ( 330 ) is shown having components F 1 , V 1  and capacitor C 1 . F 1  is a fuse providing protection against a significant system failure, such as a short circuit resulting in large currents drawn from the AC input. V 1  is a metal oxide varistor, or MOV. The MOV operates to clamp the AC input during large differential line transients. 
         [0031]    The remaining components form a single output, primary-side regulated flyback power supply. The power supply utilizes an integrated circuit U 1 , which is depicted in  FIG. 4A  as exemplary integrated circuit LNK625PG from Power Integrations™ However, other custom or commercially available power control circuitry that provide the same or similar functionalities as described herein may be employed. Integrated circuit U 1  maintains constant voltage on the primary side of transformer T 1 , thereby eliminating the requirement for voltage control on the output side of the regulator. Full wave bridge rectifier BR rectifies the input AC signal after passing thru inductor L 1  and resistor RF 1 , which is then filtered and provided to a first side of the primary winding of transformer T 1 . Inductor L 2 , capacitor C 2  and capacitor C 3  form a pi filter to reduce electromagnetic interference (EMI) noise. The second side of the primary winding of transformer T 1  is driven by integrated circuit U 1 . Leakage inductance drain voltage spikes are limited by the clamp circuit provided by resistor R 3 , resistor R 4 , capacitor C 4  and diode D 5 . In one embodiment, diode D 5  is a surface mount ultra-fast rectifier. For example, diode D 5  may be a 1 A, 1 KV diode. 
         [0032]    Output regulation is controlled by a feedback circuit comprising a primary reference winding on transformer T 1  and components R 5 -R 8 , diode D 6  and capacitors C 5 -C 6 . Diode D 6  may be a switching diode, such as a standard silicon 1N4148 diode. The secondary side of the transformer T 1  is rectified by diode D 7 . Resistor R 10  and capacitor C 9  connected across diode D 7  reduce high frequency ringing and EMI. The +5V output is filtered by components inductor L 3 , capacitor C 7  and capacitor C 8 . Finally, resistor R 9  provides a preload to maintain the output voltage if no load is applied. In one embodiment, diode D 7  is a surface mount ultra-fast rectifier. For example, diode D 7  may be a 1 A, 1 KV diode. 
         [0033]    With reference to  FIG. 4B , the schematic illustrates a portion  410  of the control circuitry related to control of the diffuser assembly. For example,  FIG. 4B  illustrates circuit details of switch assembly  310 , PWM generator  338 , lamp driver  334 , and motor driver  336  of  FIG. 3 . In one embodiment, and as shown in  FIG. 4B , switch assembly  310  (also referenced as  210  in  FIG. 2 ) comprises a switch and a potentiometer. The switch assembly provides the user control of the diffuser, and is located separately from the PCB assembly ( 216  in  FIG. 2 ) in this embodiment. The switch assembly is connected to circuitry on the PCB assembly via connector J 1 . In one embodiment, PWM generator  338  (depicted as U 2  in  FIG. 4B ) includes a microprocessor operative to provide PWM signals to the lamp driver and the motor driver. For example, PWM generator U 2  may be a PIC microcontroller. PIC stands for programmable (or peripheral) interface controller and refers to a family of microcontroller integrated circuits commercially available from Microchip Technology™ of Chandler, Ariz. However, various other types of microprocessors and/or microcontrollers may be utilized in accordance with the embodiments described herein. 
         [0034]    The PWM generator U 2  receives an input signal generated by a dual opto-isolator. For example, the dual opto-isolator may be an 8-pin SOIC dual-channel phototransistor output opto-isolator MOCD207 manufactured by Fairchild Semiconductor™. However, other custom or commercially available dual opto-isolators that provide the same or similar functionalities as described herein may be employed. In one embodiment, and as shown, the dual channel opto-isolator comprises opto-isolator U 4 -A and opto-isolator U 4 -B. The output of opto-isolator U 4 -A represents the zero crossover of the AC input signal and additionally provides isolation from the high voltage AC line to the low voltage DC circuitry. The input diode of opto-isolator U 4 -B is connected in reverse polarity and in parallel with the input diode of opto-isolator U 4 -A. 
         [0035]    The switch and potentiometer arm of the switch assembly are connected to additional inputs of the PWM generator U 2  through connector J 1 . PWM generator U 2  utilizes the zero crossover signal generated by opto-isolator U 4 -A as a start point to which a delay is added before generating a pulse to be used to drive the lamp or motor. In one embodiment, the delay is a function of the voltage provided by the potentiometer located in the switch assembly. PWM generator U 2  provides two pulse width controlled output signals, one for each of the lamp driver circuitry and the motor driver circuitry, respectively. 
         [0036]    The operation of the PWM generator is as follows. If the switch contact in the switch assembly ( 210 / 310 ) is shorted to the circuit common, then the PWM generator U 2  does not send a signal to either the lamp driver circuitry or the motor driver circuitry, and the pump motor and the lamp are completely off. When the control switch is rotated, the switch opens and the outputs are enabled. A linear voltage is generated by the potentiometer as it rotates clockwise. The potentiometer arm provides a voltage to the PWM generator U 2 , which drives the motor and lamp until full rotation is reached. Specifically, PWM generator U 2  reads the voltage from the potentiometer, and calculates the PWM signal to send to the motor driver circuitry. The motor control signal is an increasing duty cycle PWM signal. This signal ramps up from the minimum level required to start the pump motor to the full 100%. Resistor R 15 , capacitor C 12  and diode D 8  operate to filter the PWM signal to the motor driver circuitry to smooth the signal to a DC level, which is then amplified through transistor TX 1  in order to drive the pump motor. Transistor TX 1  may be a bipolar power transistor, such as NJT4031 from ON Semiconductor™. Diode D 9  and capacitor C 13  are used to eliminate electrical noise generated by the motor as it runs. Diode D 9  may be a switching diode, such as a standard silicon 1N4148 diode. 
         [0037]    The PWM generator U 2  also reads the zero crossing signal and calculates the delay time from the zero crossing to fire the TRIAC SC 1  and power the lamp. TRIAC SC 1  may be, for example, TRIAC BT131 from NXP™. However, other custom or commercially available TRIACs that provide the same or similar functionalities as described herein may be employed. As the potentiometer voltage ramps up, the PWM generator U 2  calculates the proper firing angle to ramp the root mean square (RMS) power to the lamp so it brightens in a linear fashion as the arm of the potentiometer is rotated. In one embodiment, PWM generator U 2  may be programmed to accommodate for the pulse width variations due to the difference in line frequencies of 50 Hz and 60 Hz. Programming of the microcontroller (microprocessor) is accomplished by connecting to the microcontroller via connector J 2 . 
         [0038]    The lamp driver circuitry includes DIAC U 3 , TRIAC SC 1 , and current limiting resistors R 11  and R 12 . In one embodiment, DIAC U 3  is an opto-isolated DIAC, such as MOC3023 manufactured by Fairchild Semiconductor™. However, other custom or commercially available opto-isolated DIACs that provide the same or similar functionalities as described herein may be employed. The lamp is connected between AC power hot side, AC-HI, at bulb socket X 3 , while the neutral side of the bulb is switched through TRIAC SC 1  via bulb socket X 4 . DIAC U 3  maintains high voltage separation of the lamp voltage from the control circuitry. 
         [0039]    At the proper firing angle, as controlled by the potentiometer, PWM generator U 2  provides a low signal level to the input of DIAC U 3  turning the output of the DIAC on, thereby connecting the neutral side of the lamp to the gate input of TRIAC SC 1  through resistor R 11 . This, in turn, triggers TRIAC SC 1  on, thereby turning on the lamp. PWM generator U 2  then turns off DIAC U 3  prior to the start of the next zero crossover detection. TRIAC SC 1  then turns off as the AC voltage goes through its next zero crossover causing the lamp to go off. The above control signals continuously repeat for each half cycle of the AC line voltage. The brightness of the lamp is a function of the RMS power through the lamp, as controlled by the user&#39;s adjustment of the potentiometer. 
         [0040]    PWM generator U 2  is programmed such that the brightness of the lamp is synchronized to the speed of the motor. A rotation of the potentiometer which increases the voltage at the potentiometer arm results in an increase to the speed of the motor as well as an increase in the brightness of the lamp. A rotation of the potentiometer which decreases the voltage at the potentiometer arm results in a decrease to the speed of the motor as well as a decrease in the brightness of the lamp. Accordingly, the intensity of the light emitted from the light source is synchronously controlled with, and proportional to, the transformation rate of the fragrance oil. 
         [0041]      FIGS. 5A through 5C  illustrate example signal waveforms associated with a diffuser assembly, according to an illustrative embodiment. More particularly,  FIG. 5A  illustrates an example of the waveform of a 120 VRMS, 60 Hz input line voltage  502 .  FIG. 5A  further illustrates an example of the waveform  504  appearing across the lamp  304  resulting from the turn on delay generated by the PWM generator  338  to the lamp driver  334  as a function of the position of the potentiometer arm. That is,  FIG. 5A  shows the input AC line voltage waveform superimposed on the AC waveform appearing across a triac controlled lamp. 
         [0042]    In the example waveforms illustrated, the potentiometer arm is positioned approximately midway between GND (ground) and 5V, resulting in a voltage of approximately 2.5 volts which is coupled to the input of the PWM generator  338 . The PWM generator  338  converts this voltage into a PWM signal  506  ( FIG. 5B ) which drives the lamp driver  334  and PWM signal  508  ( FIG. 5C ) which drives the motor driver  336 . For example, lamp driver signal  506  is a PWM signal which starts at a high level, i.e., 5V, at each zero crossing of the input line voltage  502 . Lamp driver signal  506  remains high during a turn on delay period  510 , during which the lamp remains turned off. The turn on delay period  510  is controlled by positioning the potentiometer arm. It is to be understood that positioning the potentiometer arm closer to 5V results in reducing the turn on delay  510 , while positioning the potentiometer arm closer to GND results in an increase to the turn on delay  510 . 
         [0043]    In the example illustrated, the turn on delay  510  of lamp driver signal  506  is shown to be slightly more than a quarter cycle of the input line voltage  502  or approximately 5 milliseconds (ms). At the end of the turn on delay, lamp driver signal  506  from the PWM generator  338  transitions to a low level, i.e., GND, triggering TRIAC SC 1  via opto-coupled DIAC U 3 . As illustrated by waveform  504 , after the delay time  510 , the AC line voltage is switched across the lamp  304  and the lamp turns on. When the AC voltage across the lamp crosses 0V (zero-crossing), the TRIAC turns off, turning the lamp off. After each zero crossing of the AC input line voltage  502 , the PWM generator  338  generates a high level on lamp driver signal  506  for the duration of the turn on delay  510  and then transitions to GND for the remainder of the half cycle of the AC input line voltage  502 . In another embodiment, signal  506  may not transition to GND for the remainder of the half cycle of the AC input line voltage  502 , but rather may transition to GND for a period less than the remainder of the half cycle, such as, for example, 100 microseconds (usec). As the turn on delay  510  increases, the average power across the lamp decreases resulting in dimming the lamp. As the turn on delay  510  decreases, the average power across the lamp increases resulting in the lamp becoming brighter. 
         [0044]    Similar to the operation of the lamp  304 , the PWM generator  338  generates a PWM signal  508  to the motor driver  336 . The motor drive PWM signal  508  from the PWM generator  338  is inverted from the lamp drive PWM signal  506 . That is, signal  508  remains at a low level, GND, during the turn on delay period and then transitions to a high level, 5V, to drive the motor  314 . 
         [0045]    It should be noted that in other embodiments, the turn on delay for the motor driver  336  may be the same or different from the turn on delay for the lamp driver  334 . The relative timing of the lamp driver turn on delay period and the motor driver turn on delay period is a function of synchronizing the lamp brightness with respect to the diffusion rate of the fragrance oil. 
         [0046]      FIG. 6  illustrates an example of potentiometer settings and the resultant turn on delay and the angle in which the lamp  304  will turn on each half cycle of the AC input line voltage for the 60 Hz example. More specifically, table  600  shows illustrative turn on delays for potentiometer settings ranging between 5V and GND. The table is exemplary only and is therefore not intended to limit embodiments of the invention. Furthermore, the PWM generator  338  may be programmed to determine the turn on delays and/or other operational parameters by calculating values in real time or by storing and accessing pre-calculated values in a look up table. Also, in alternative embodiments, the motor  314  can run at frequencies other than 60/50 Hz (e.g., higher frequency F), but still yield the same or similar results. The inventive teachings are not limited to the AC line voltage characteristics described in illustrative embodiments. It is also to be appreciated that given the inventive teachings herein, those of ordinary skill in the art will realize straightforward alternatives to the exemplary implementation details described herein. 
         [0047]    Furthermore, while not intended to be limiting, below is a table of component values of various components in embodiments shown in  FIGS. 4A and 4B : 
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
               
               
               
             
               
               
               
               
             
               
               
               
             
               
               
               
               
             
               
               
               
             
               
               
               
               
             
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Component 
                 Value 
               
               
                   
                   
               
             
             
               
                   
                 RF1 
                  10Ω 
               
             
          
           
               
                   
                 R3 
                 270 
                 KΩ 
               
             
          
           
               
                   
                 R4 
                 330Ω 
               
             
          
           
               
                   
                 R5 
                 28.7 
                 KΩ 
               
               
                   
                 R6 
                 4.42 
                 KΩ 
               
             
          
           
               
                   
                 R7 
                  12Ω 
               
             
          
           
               
                   
                 R8 
                 8.2 
                 KΩ 
               
             
          
           
               
                   
                 R9 
                 820Ω 
               
               
                   
                 R10 
                  18 Ω 
               
               
                   
                 R11 
                 470Ω 
               
               
                   
                 R12 
                 470Ω 
               
             
          
           
               
                   
                 R13 
                 33 
                 KΩ 
               
               
                   
                 R14 
                 10 
                 KΩ 
               
             
          
           
               
                   
                 R15 
                 100Ω 
               
             
          
           
               
                   
                 C1 
                 0.1 
                 uF 
               
               
                   
                 C2 
                 6.8 
                 uF 
               
               
                   
                 C3 
                 6.8 
                 uF 
               
               
                   
                 C4 
                 1000 
                 pF 
               
               
                   
                 C5 
                 1 
                 uF 
               
               
                   
                 C6 
                 1 
                 uf 
               
               
                   
                 C7 
                 1000 
                 uF 
               
               
                   
                 C8 
                 470 
                 uF 
               
               
                   
                 C9 
                 1000 
                 pF 
               
               
                   
                 C10 
                 0.1 
                 uF 
               
               
                   
                 C11 
                 0.1 
                 uF 
               
               
                   
                 C12 
                 10 
                 uF 
               
               
                   
                 C13 
                 0.1 
                 uF 
               
               
                   
                 L1 
                 3 
                 mH 
               
               
                   
                 L2 
                 10 
                 mH 
               
               
                   
                 L3 
                 3.3 
                 uH 
               
               
                   
                 F1 
                 3.15 
                 A 
               
               
                   
                   
               
             
          
         
       
     
         [0048]    Ω is ohms, uF is microfarads, uH is microhenrys, and mH is millihenrys. It is to be appreciated that the values given in the above table are examples, and thus other values can be used to achieve one or more of the advantages of the inventive teachings presented herein. 
         [0049]    Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be made by one skilled in the art without departing from the scope or spirit of the invention.