Osram Sylvania Inc.

Alexander A Sapozhnikov

Valery A Godyak

Benjamin Alexandrovich

Kenneth R Hutcherson

An electrodeless fluorescent lamphas an envelopethat includes a chamber. A coreof magnetic material, preferably ferrite, is positioned in the chamberand has a first windingsurrounding the core and having first and second lead-in wires, attached to a high frequency voltage supply or ballast. A second windingsurrounds the core, respective turns of the second windingbeing located adjacent turns of the first windingand electrically insulated therefrom. The second windinghas a free endand has another endconnected to one of the lead-in wires, for example. A braided sheathsurrounds the other of the lead-in wires. The first windingis generally called the RF antenna. The braided sheathis connected to the local ground. This inexpensive solution alone reduces the conductive EMI level sufficiently to pass all existing regulations on such interference with significant reserve.

RF induction lamp with reduced electromagnetic interference

An electrodeless fluorescent lamp () having a burner (), a ballast housing () containing a ballast () and a screw base () for connection to a power supply. A reentrant cavity () is formed in the burner () and an amalgam receptacle () containing amalgam () is formed as a part of the reentrant portion and in communication with the burner (). A housing cap (), formed of a suitable plastic, connects the burner () to the ballast housing () and a suitable adhesive () fixes the burner to the housing cap (). An EMI cup () is formed as an insert to fit into the ballast housing (), which also is formed of a suitable plastic, and has a bottom portion () and an EMI cap () with an aperture () therein closing an upper portion (). The EMI cup () and the EMI cap () are preferably formed from 0.5 mm brass. The amalgam receptacle () extends through the aperture () and into the cup (). For a fixed amalgam position, changing the aperture size allows adjustment of the amalgam tip temperature, and thus, allows control of the system lumen output, efficacy, CCT and CRI, all of which are dependent on the amalgam temperature.

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Framingham, MA, United States of America

Alexander A Sapozhnikov