Improvements in or relating to electrical supply arrangements for supplying apparatus with electrical power from either alternating or direct current mains

摘要

362,508. Supplying consuming devices; converting. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York, U.S.A., JEFFCOCK, R. J. P., 21, Kensington Court, and GROTEFELD, C. H. F., 290, Cricklewood Lane, both in London. Sept. 6, 1930, No. 26669. [Classes 38 (ii) and 38 (iv).] Comprises apparatus for obtaining a supply of alternating current from either D.C. or A.C. mains. The Figure shows the simplified circuit diagram of apparatus for use with portable talking motion picture apparatus. Assuming that the plug 10 is coupled with a D.C. mains and the switch 14 is set so that contact 34 bridges contacts 12, 16 and contact 36 bridges contacts 32, 30. The four pin plug 36 from an inverted rotary converter 40 is inserted in the socket member 18, so that D.C. is supplier to the rotary converter and A.C. from it to the tapped winding of the autotransformer 28. The projector lamp 52 is supplied from 10 through a variable resistance 48, a rheostat 49 and a switch 50. Alternatively it may be supplied from an auxiliary winding 54 on the transformer 28 by the rheostat arm 58 being moved from the resistance 49 to the resistance 56. A universal motor 44 is connected across the input supply 10 and drives film moving mechanism &c. If the .input 10 is connected to an A.C. supply, the plug 36 is replaced by a plug 37 which connects the supply direct to the transformer 28.