Regular Article

Cold starting of fluorescent lamps – part II: experiments on glow times and electrode damaging

¹ Institut für Physik, Lehrstuhl für Experimentalphysik II, Universität Augsburg, Universitätsstraße 1, 86159 Augsburg, Germany
² LEDVANCE GmbH (former part of OSRAM AG), Berliner Allee 65, 86136 Augsburg, Germany

^a e-mail: Reinhard.Langer@physik.uni-augsburg.de

Received: 14 July 2016
Revised: 21 October 2016
Accepted: 24 November 2016
Published online: 9 January 2017

Abstract

In the present work we present experiments on cold start and the resulting electrode damaging (reducing lamp life) of AC driven fluorescent lamps. The crucial parameter is the glow time, determined from time resolved measurements of lamp voltage and current. The relation between the energy consumed during glow phase and the glow time is studied. It turns out that there is no common threshold of energy until the glow-to-arc transition takes place, but strong energy input into the lamp yields short glow times. The transient behaviour from the glow to the arc regime is investigated and the stable operation points of the arc discharge are determined, yielding an arc discharge voltage-current characteristics of the lamp type investigated. The electrode damage is investigated as a function of the open source voltage and the ballast resistance. Subsequent cold starts lead to an increase of the glow time due to electrode damaging, i.e., the electrode damage accumulates. Different regeneration procedures and their effectiveness are compared. Regeneration burning turns out to be more effective than heating up the electrode. A criterion for avoiding high electrode damage is obtained, indicating that the average power during glow time should exceed 20 W.