GB633036A - Improvements in and relating to electric fluorescent lighting systems - Google Patents

Abstract

633,036. Supply systems for space discharge lamps. PESTARINI, J. M. Nov. 20, 1947, No. 30805. Convention date, Nov. 20, 1946. [Class 38 (iv)] [Also in Group XXXVII] In a D.C. discharge lamp lighting system a metadyne 10 of the generator or transformer type is included in the lamp circuit during the starting period to provide the high starting voltage required, by switching means 14, which, in the arrangement shown, connects the lamp 7 direct across the secondary brushes b, d of the machine and in an alternative arrangement (Figs. 4 and 5, not shown) connects the machine in series with the supply leads. The switching means may include contacts 12 or 13 or both for controlling respectively the circuit between the primary brushes a, c, and the stator winding 11 circuit to de-energize the machine before change-over is effected. To afford automatic reduction of the primary current when the secondary circuit is operated a further winding (Fig. 4, not shown) may be connected between the primary brushes. A polarity reversing switch 1-6 may be inserted in the supply leads and operated periodically to avoid lamp striation. In cases where the normal supply is derived from a generator forming part of the system the metadyne may be coupled thereto. Two forms of manually-operated starting switches, which provide the correct sequence and starting period are described (see Group XXXVII).