Browse Prior Art Database

Fluorescent Lamp Operation

IP.com Disclosure Number: IPCOM000080569D
Original Publication Date: 1974-Jan-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Routt, WM: AUTHOR

Abstract

Fluorescent lamps operated from a single multilamp ballast may be switched on and off independently, by selectively shorting the lamps with an appropriate alternating-current switch such as a triac.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Fluorescent Lamp Operation

Fluorescent lamps operated from a single multilamp ballast may be switched on and off independently, by selectively shorting the lamps with an appropriate alternating-current switch such as a triac.

Lamps 1, 2, and 3 are each connected to a high-impedance multi-lamp ballast 5. Each of the lamps may be selectively switched on and off by operation of triac switches 7, 8, and 9. The steady-state lamp currents are not significantly affected due to the high-output impedance of the ballast. Light output thus varies only slightly for a given lamp as other lamps are turned on and off. The utilization of a triac or other zero current turn-off devices prevents transient current effects on the light output. Use of fluorescent phosphors with relaxation times much longer than the duration of anticipated current transients can be used to reduce transient light output effects, if instantaneous switching devices are used.

1

Page 2 of 2

2

[This page contains 3 pictures or other non-text objects]