GB719296A - Stroboscopic light source - Google Patents

Abstract

719,296. Discharge lamps. FRUNGEL, F. Feb. 7, 1951 [Feb. 9, 1950; May 30, 1950], No. 3016/51. Class 39(1) A demountable stroboscopic spark-gap comprises a transparent hollow cylinder 1, Fig. 3, for example of glass, quartz or acrylic resin, gas-tight end closures for the cylinder comprising a detachable cover 3 and a detachable bottom plate 4, two spark electrodes 14, 15 mounted substantially at the axis of the hollow cylindrical vessel thus formed, lead-in means 5, 16 for connecting the electrodes to an external storage condenser 28, Fig. 2, and ignition means such as annular electrode 18 for producing controlled spark-overs across the gap. By reducing the inductance of the leads and adjusting the spark resistance to equal the aperiodic resistance of the discharging circuit, as described in Specification 719,356, sparks of high brilliancy at 10,000 amps. and repetition rates of up to 1,000 per second are obtained. Sealing gaskets 2 are compressed by the tie rods 5 acting also as leads to electrode 14, which is rotatably mounted on internal bracket 8; rotation by an air-tight movable plug 10 and arm 11 enables the distance between the electrodes to be adjusted and also actuates wiper 26 for clearing deposits from the wall. Alternative means for adjusting the electrode spacing may comprise non-airtight-movable plug 36 Fig. 5, permitting linear movement of electrode 14 against spring 37, airtightness being secured by bellows 35. Main electrode 15 and ignition electrode 18 are sealed through plate 4 by gaskets 17, 20, the gap between them being ¢ to 1/3 of the gap length; the ignition electrode may also take the form of a needle extending axially within a bore in the main electrode. Cooling ribs 21 are provided on cover 3 and electrode 16 for convective or forced air cooling. Plate 4 carries reflector 27, Fig. 2, and the circuit components 28 and C described in Specification 719,356 are mounted behind it. The filling, introduced by tyre-type valve 12, comprises rare gas above atmospheric pressure with an addition of an electronegative gas such as water-vapour, carbon dioxide or the gas known under the Registered Trade Mark " Freon". The electrodes are of a sintered mixture of powdered tungsten with silver or copper.