POWER AND COMPONENT SAVING TECHNIQUES
Original Publication Date: 1987-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
It is not considered good practice to use incandescent bulbs to illuminate panel indicators because they tend to burn out and need replacement. LED'S are much more reliable. On the other hand, redundant bulbing is a problem since the second bulb is already old when the first bulb burns out. Among the methods to extend the life of bulbs past the planned life of the product are to run at slightly below their rated voltage. This improves life greatly and causes only a small decrease in brightness. Another method is to run the lamp at low voltage when it is supposed to be "off' in order to keep the filament warm and reduce in-rush current when it is turned on. There are two additional methods.