Ceiling fan with a light-sensitive circuit
First Claim
1. A light-sensitive circuit for use with at least one light, the light-sensitive circuit comprising:
- a resistive network including a photocell, the photocell being responsive to a sensed ambient illumination level and having a threshold illumination associated therewith, the resistive network having an equivalent resistance varying as a function of the sensed ambient illumination level and the threshold illumination level;
a firing capacitor responsive to the resistive network and charging to a firing voltage at a rate corresponding to the equivalent resistance;
a trigger generating circuit responsive to the firing capacitor and generating a trigger signal in response to the firing capacitor being substantially charged to the firing voltage;
an AC power switch responsive to the trigger signal, the AC power switch coupling the AC power signal to the light in response to the trigger signal for a selectable portion of a cycle of the AC power signal, the selectable portion of the cycle of the AC power signal corresponding to a current provided to the light; and
a multi-position switch coupled to the light, the light-sensitive circuit, and the AC power signal, the multi-position switch having at least an off position, an on position, and a light-sensitive position, the multi-position switch decoupling the light and the light-sensitive circuit from the AC power signal while in the off position, the multi-position switch coupling the light to the AC power signal while in the on position, and the multi-position switch coupling the light to the AC power signal through the light-sensitive circuit while in the light-sensitive position, the light flickering while a value of the current is within a flicker region, the light-sensitive circuit including a cutoff circuit operatively coupled to the light-sensitive circuit, the cutoff circuit limiting the selectable portion of the cycle of the AC power signal provided to the light such that light will not illuminate while the value of the current is within the flicker region, thereby preventing the light from flickering.
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Accused Products
Abstract
A ceiling fan assembly includes a fan and a light-sensitive circuit for controlling an illumination level of a light as a function of an ambient illumination level surrounding the ceiling fan assembly by selectively controlling or fixing a conduction phase angle of an AC power signal provided to the light. The light-sensitive circuit includes a photocell, a phase control circuit and a cutoff circuit which prevents flicker at low illumination levels. The photocell is responsive to the ambient illumination level and has a conduction state. The conduction state changes in response to the ambient illumination level. The phase control circuit selectively varies or fixes a conduction phase angle associated with the AC power signal, which correspondingly determines a variation in the illumination level of the light. In response to the photocell, the phase control circuit selectively varies or fixes the conduction phase angle, and thus the illumination level associated with the light when the photocell exhibits an open circuit, and conversely, prevents the AC power signal from being provided to the light when the photocell exhibits a short circuit.
53 Citations
21 Claims
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1. A light-sensitive circuit for use with at least one light, the light-sensitive circuit comprising:
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a resistive network including a photocell, the photocell being responsive to a sensed ambient illumination level and having a threshold illumination associated therewith, the resistive network having an equivalent resistance varying as a function of the sensed ambient illumination level and the threshold illumination level;
a firing capacitor responsive to the resistive network and charging to a firing voltage at a rate corresponding to the equivalent resistance;
a trigger generating circuit responsive to the firing capacitor and generating a trigger signal in response to the firing capacitor being substantially charged to the firing voltage;
an AC power switch responsive to the trigger signal, the AC power switch coupling the AC power signal to the light in response to the trigger signal for a selectable portion of a cycle of the AC power signal, the selectable portion of the cycle of the AC power signal corresponding to a current provided to the light; and
a multi-position switch coupled to the light, the light-sensitive circuit, and the AC power signal, the multi-position switch having at least an off position, an on position, and a light-sensitive position, the multi-position switch decoupling the light and the light-sensitive circuit from the AC power signal while in the off position, the multi-position switch coupling the light to the AC power signal while in the on position, and the multi-position switch coupling the light to the AC power signal through the light-sensitive circuit while in the light-sensitive position, the light flickering while a value of the current is within a flicker region, the light-sensitive circuit including a cutoff circuit operatively coupled to the light-sensitive circuit, the cutoff circuit limiting the selectable portion of the cycle of the AC power signal provided to the light such that light will not illuminate while the value of the current is within the flicker region, thereby preventing the light from flickering. - View Dependent Claims (2)
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3. A light-sensitive circuit for use with at least one light, the light-sensitive circuit comprising:
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a resistive network including a photocell, the photocell being responsive to a sensed ambient illumination level and having a threshold illumination associated therewith, the resistive network having an equivalent resistance varying as a function of the sensed ambient illumination level and the threshold illumination level;
a firing capacitor responsive to the resistive network and charging to a firing voltage at a rate corresponding to the equivalent resistance;
a trigger generating circuit responsive to the firing capacitor and generating a trigger signal in response to the firing capacitor being substantially charged to the firing voltage;
an AC power switch responsive to the trigger signal, the AC power switch coupling the AC power signal to the light in response to the trigger signal for a selectable portion of a cycle of the AC power signal, the selectable portion of the cycle of the AC power signal corresponding to a current provided to the light; and
a switch coupled to the light, the light-sensitive circuit, and the AC power signal, the switch having at least an off position, an on position, and a light-sensitive position, the switch decoupling the light and the light-sensitive circuit from the AC power signal while in the off position, the switch coupling the light to the AC power signal while in the on position, and the switch coupling the light to the AC power signal through the light-sensitive circuit while in the light-sensitive position. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of controlling an illumination level of at least one light as a function of a sensed ambient illumination level comprising the steps of:
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coupling a light-sensitive circuit to the at least one light, the light-sensitive circuit including a photocell having a threshold illumination level associated therewith, the photocell being responsive to a sensed ambient illumination level;
controlling the illumination level of the at least one light with the photocell such that the illumination of the light is responsive to the sensed ambient illumination level by the photocell, wherein the portion of the cycle of the AC power signal provided to the light corresponds to a current, and wherein the light flickers while a value of the current is within a flicker region; and
limiting the portion of the cycle of the AC power signal provided to the light such that the light will not illuminate while the value of the current is within the flicker region, thereby preventing the light from flickering. - View Dependent Claims (15, 16, 17, 18, 19, 20)
turning the at least one light on when the sensed ambient illumination level is less than the threshold illumination level of the photocell; and
turning the at least one light off when the sensed ambient illumination level is greater than the threshold illumination level of the photocell.
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16. A method of controlling an illumination level of at least one light as a function of a sensed ambient illumination level as defined in claim 18, wherein the photocell exhibits one of an open circuit and a short circuit in response to the sensed ambient illumination level, the method including the step of permitting the firing capacitor to charge to the firing voltage at a time when the photocell is exhibiting the short circuit and the equivalent resistance is at a minimum value.
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17. A method of controlling an illumination level of at least one light as a function of a sensed ambient illumination level as defined in claim 14, wherein the light is in a light fixture coupled to a ceiling fan assembly.
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18. A method of controlling an illumination level of at least one light as a function of a sensed ambient illumination level as defined in claim 14, wherein the light-sensitive circuit includes a resistive network having an equivalent resistance associated therewith, a firing capacitor operatively coupled to the resistive network, a diac operatively coupled to the firing capacitor, and a triac operatively coupled to the diac, the resistive network including the photocell, the method including the steps of:
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(a) charging the firing capacitor to a firing voltage at a rate corresponding to the equivalent resistance;
(b) firing the diac in response to the firing capacitor being charged to the firing voltage;
(c) generating a trigger signal in response to the diac firing; and
(d) triggering the triac into a conduction mode in response to the trigger signal such that a portion of a cycle of an AC power signal provided to the light-sensitive circuit is provided to the at least one light causing the at least one light to illuminate at the illumination level corresponding to the portion of the cycle of the AC power signal.
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19. A method of controlling an illumination level of at least one light as a function of a sensed ambient illumination level as defined in claim 18, including the steps of:
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providing a multi-position switch coupled to the at least one light, the light-sensitive circuit, and the AC power signal, the multi-position switch having at least an on position, an off position, and a light-sensitive position;
performing steps (a) through (d) while the multi-position switch is in the light-sensitive position;
coupling the at least one light to the AC power signal in response to the multi-position switch being in the on position; and
decoupling the light and the light-sensitive circuit from the AC power signal in response to the multi-position switch being in the off position.
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20. A method of controlling an illumination level of at least one light as a function of a sensed ambient illumination level as defined in claim 18, wherein the photocell exhibits one of an open circuit and a short circuit in response to the sensed ambient illumination level, the method including the step of preventing the firing capacitor from charging to the firing voltage at a time when the photocell is exhibiting the short circuit.
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21. A light-sensitive circuit for use with at least one light, the light-sensitive circuit comprising:
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a resistive network including a photocell, the photocell being responsive to a sensed ambient illumination level and having a threshold illumination associated therewith, the resistive network having an equivalent resistance varying as a function of the sensed ambient illumination level and the threshold illumination level;
a firing capacitor responsive to the resistive network and charging to a firing voltage at a rate corresponding to the equivalent resistance;
a trigger generating circuit responsive to the firing capacitor and generating a trigger signal in response to the firing capacitor being substantially charged to the firing voltage;
an AC power switch responsive to the trigger signal, the AC power switch coupling the AC power signal to the light in response to the trigger signal for a selectable portion of a cycle of the AC power signal, the selectable portion of the cycle of the AC power signal corresponding to a current provided to the light; and
a multi-position switch coupled to the light, the light-sensitive circuit, and the AC power signal, the multi-position switch having at least an off position, an on position, and a light-sensitive position, the multi-position switch decoupling the light and the light-sensitive circuit from the AC power signal while in the off position, the multi-position switch coupling the light to the AC power signal while in the on position, and the multi-position switch coupling the light to the AC power signal through the light-sensitive circuit while in the light-sensitive position, the resistive network including a fixed resistance which increases the equivalent resistance and decreases the portion of the cycle of the AC power signal provided to the light such that the light functions as a night light at less than maximum illumination.
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Specification