| 摘要 |
1,208,509. Discharge lamp circuits. SYLVANIA ELECTRIC PRODUCTS Inc. 3 July, 1968 [3 July, 1967], No. 42315/69. Divided out of 1,208,508. Heading H2H. A circuit for a fluorescent lamp 1, having two cathode filaments 8, 9 between which an electrical discharge is to be passed, includes an inductance coil 12 connecting one end of each filament to the other filament, a battery 15 connected across the other ends of the filaments, and an oscillator 13 connected to supply A.C. between the cathode filaments, the inductance coil passing D.C. from the battery but opposing the passage of A.C. from the oscillator. The lamp shown is described in Specification 1,208,508 and comprises two spaced sets of filaments, each set containing a cathode filament 8, 9 coated with electron-emitting material and an incandescent filament 10, 11. The incandescent filaments provide illumination when the discharge is inhibited by a low vapour pressure due to low ambient temperature, e.g. in an automobile at starting in winter. In an alternative circuit (Fig. 2, not shown) the transformer 17 is omtited. The oscillator 13 is connected in series with a capacitor across the leads 5 and 7 in parallel with the battery 15 and a second inductance coil. |
