Dimmer with photo sensor and high/low clamping

Abstract

Provided is a circuit for controlling a level of brightness of a light electrically coupled to a dimming circuit including control leads configured to provide a dimming control voltage to the dimmable driver, the dimming control voltage having a permissible voltage range. The circuit includes a photo sensor for detecting an ambient light level in the vicinity of the light and a clamp controller for selectively reducing the dimming control voltage to a clamped voltage range less than the permissible voltage range. Also included is a feedback controller for adjusting the dimming control voltage in response to a detected ambient light level, the dimming control voltage being within the clamped voltage range.

Description

I. FIELD OF THE INVENTION[0001]The present invention relates generally to the field of light dimming control. More particularly, the present invention relates to controlling the dimming range of a light fixture coupled to a dimmer.II. BACKGROUND OF THE INVENTION[0002]The Illuminating Engineering Society of North America recommends a 30-50 foot-candle (fc) range for ambient (general) office lighting, yet most workspaces are lit to 60 fc on average. Over-lighting can cause unnecessary eye strain for occupants and higher energy costs for companies. Under-lighting can also cause unnecessary eye strain and provide a less pleasing or less productive workspace.[0003]Further, in large or open workspaces, whether the spaces are commercial, industrial, retail, or public, such as office buildings, warehouses, schools, malls, and the like, the amount of light provided within the space is impacted not only by the artificial lighting system installed in the space but also by the amount of natural...

AI Technical Summary

Benefits of technology

The patent is about a circuit and system for controlling the brightness of a light that can be dimmed. The circuit includes a photo sensor to detect the ambient light level and a clamp controller to reduce the brightness of the light to a lower range. A feedback controller adjusts the brightness based on the detected ambient light level to make it match a desired level. This technology allows for precise control of the brightness of the light, even at low light levels, using a simple circuit and method.

Problems solved by technology

Over-lighting can cause unnecessary eye strain for occupants and higher energy costs for companies.

Under-lighting can also cause unnecessary eye strain and provide a less pleasing or less productive workspace.

Further, in large or open workspaces, whether the spaces are commercial, industrial, retail, or public, such as office buildings, warehouses, schools, malls, and the like, the amount of light provided within the space is impacted not only by the artificial lighting system installed in the space but also by the amount of natural light entering the space through windows, doors, and skylights.

However, merely adding more photo sensors to different banks of lights within such large workspace does not necessarily create a pleasing or uniform lighting environment.

Nor does it address the end user's needs, which may be to have higher or lower lighting in selected areas of the workspace.

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