Quiet fan speed control with linear adjustment actuator
AssigneeLutron Electronics Co., Inc.
InventorRobert S. Hanna
Life of this patent
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Abstract
A fan speed control adjusts the speed of an electric fan motor without producing audible noise at frequencies above about 60 Hz. A linear slide switch is positionable in each of four discrete positions to connect various capacitances in series with the motor to limit the power provided to the motor from an ac source. An actuator engaging the slide switch includes detents to urge the switch into each of the four positions. The urging force is a maximum approximately half-way between adjacent positions and decreases linearly to a minimum at each position. The maximum force necessary to move the switch from one position to the next is not greater than about 0.8 lb., to avoid overshoot when the actuator is operated by an extended arm.
Claims15
An apparatus for manually adjusting the speed of an electric motor driven ceiling fan, comprising:
- a) a support plate having an elongated slot and a plurality of holes for mounting to an electrical wallbox;
- b) a cradle, mounted on said support plate, having a snap retaining means;
- c) a four-position linear slide switch retained by said snap retaining means;
- d) first and second capacitors electrically connected to and mounted on either side of said slide switch;
- and
- e) an actuator, slidably retained by said cradle and extending through said elongated slot to selectively position said slide switch in each of a plurality of discrete positions to connect at least one of said capacitors in series with said electric motor.
Dependencies are inferred from the claim text.