Mr. Shawn P. Keeney Profile

Shawn P. Keeney

Engineer

SPIE Involvement:

Author

Publications (2)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 12 September 2006 Paper

Replacement of fluorescent lamps with high-brightness LEDs in a bridge lighting application

John Curran, Shawn Keeney

Proceedings Volume 6337, 633719 (2006) https://doi.org/10.1117/12.682727

KEYWORDS: Light emitting diodes, Lamps, Bridges, Light sources and illumination, Prototyping, Power supplies, Reliability, Standards development, Fourier transforms, Optical testing

Read Abstract +

There are many advantages that LEDs offer for use in general illumination. The use of LEDs in certain applications can provide improved energy efficiency. For example, in traffic lights in the United States, LED technology has taken over the market not only because of the energy savings as compared to standard incandescents, but also because of the reduced maintenance costs associated with bulb replacement and improved reliability. With useful lifetimes exceeding 40,000 hours or more, today's high flux LEDs can provide illumination solutions with replacement periods of 8 to 10 years or more. This paper will examine a bridge roadway lighting feasibility study which the authors' company recently undertook. The application required the LED units to reproduce the photometric performance of 64-inch (1.625m) fluorescent lamps. In addition, the LED units were required to survive a harsh, outdoor marine environment with an expected lifetime of 7 years or more. To achieve these results, a number of design elements were studied including: optimum heat dissipation in a sealed enclosure, ease of installation, and design of power supplies having expected lifetimes to match the LED light engines. Results of these studies will be discussed as well as illustrations of the designs chosen.

Proceedings Article | 20 October 2004 Paper

An examination of a prototype LED fire-alarm signaling appliance

John Curran, Shawn Keeney

Proceedings Volume 5530, (2004) https://doi.org/10.1117/12.558472

KEYWORDS: Light emitting diodes, Xenon, Visualization, Prototyping, Phase modulation, Time metrology, Standards development, Manufacturing, Optical testing, Visual optics

Read Abstract +

Since the introduction of the Americans With Disabilities Act in 1990, the number of visual fire alarm signals installed in the United States has grown exponentially. Virtually all of these fire alarm visual signals consist of the Xenon gas flashtube type. This technology offers high intensity along with moderate cost in a relatively small package. Typical intensities offered range from 15cd (candela) up to 185cd. With the recent advances in solid state LEDs (Light Emitting Diodes) the possibility exists to develop visual fire signals using this technology. When used in lower intensity visual appliances, LEDs offer comparable light output with much smaller optical footprints (albeit at somewhat higher estimated costs). This paper will examine the optical performance of a prototype LED visual fire signaling appliance as compared to a more conventional device. It will also evaluate a series of tests, which were run in an office environment to compare the response time of workers for both the conventional Xenon fire signal appliance as well as the prototype LED device. Measurements for each test subject were taken over a two to three day period. Parameters measured included time of day, size of office and general ambient lighting. Results of these experiments indicate that the general response times of the test subjects were similar for the two types of fire signals. The paper concludes with a discussion of the potential for LED-type fire signaling devices as well as some of the potential technology obstacles still to be overcome.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years