US 4,227,118 A · Circuits for operating electric discharge lamps

Abstract

An electric discharge lamp circuit arrangement wherein rapid starting of the lamp is obtained by charging a ballast impedance capacitance via a unidirectional current conducting path in a sense such as to breakdown a voltage breakdown device in the control electrode lead of a controllable switching device connected with the lamp to provide a current path between the supply terminals comprising, in series, the capacitance, heating means for the lamp main electrodes and the switching device. On breakdown, the switching device temporarily conducts to complete the series path and cause a pulse of current to flow through the heating means, whereafter the capacitor recharges and a further current pulse is produced. The unidirectional current path may extend through the breakdown device or by-pass the breakdown device via a rectifier.

Claims9

Dependent claims

An electric discharge lamp circuit arrangement comprising:

a pair of terminals for connection to an alternating current supply;
a ballast impedance comprising a capacitance connected between one of said terminals and one of a pair of main discharge electrodes of the lamp;
a connection between the other of said terminals and the other of said main electrodes;
heating means for at least one of said main electrodes a controllable switching device connected with the lamp to provide a current path between said pair of terminals comprising, in series, said capacitance, said heating means and said switching device;
and a voltage breakdown device connected between the control electrode and a main electrode of said switching device;
the voltage breakdown device being a reverse breakdown rectifying device so as to provide a unidirectional current conducting path whereby said capacitance charges from said supply while said switching device is open in a sense such as to bias said breakdown device towards breakdown.

3 more elements

Dependencies are inferred from the claim text.

Circuits for operating electric discharge lamps

Life of this patent

Circuits for operating electric discharge lamps

Life of this patent

Abstract

Claims9