Einrichtung zur Kontrolle der Batteriespannung einer elektrisch angetriebenen Filmkamera

983, 307. Photo-electric exposure control; electric battery tests. K. VOCKENHUBER. Sept. 21, 1961 [Sept. 23, 1960], No. 33808/61. Headings G1A and G1U. [Also in Division H2] In a battery operated kinematograph camera having an exposure control of the type in which a resistor in a photo-cell circuit takes account of frame speed changes, the resistor is retained in circuit with the galvanometer when the latter is used to check the battery voltage. The camera motor 7 is fed from the battery 9 in circuit with a shortable resistor 11 to vary the frame speed. The switch 10 is ganged with a switch 5 which connects a resistor 6 in parallel with the exposure meter 1 to allow for the change in frame speed. The battery voltage is checked by closing switches 13, 14 and masking the photo-cell so that it provides a high resistance shunt to the meter. Since approximately double the battery voltage is required to operate motor 7 at double the speed, the presence of resistor 6 results in the pointer of meter 1 always registering with the same mark when the battery voltage is satisfactory. Further slight correction may be made by varying resistor 12 on operation of switches 5 and 10. The mask may be combined with an operating member for switches 13, 14, Figs. 3 and 4, (not shown) so that the latter cannot be operated unless the former is in place.