Arrangement for checking the battery voltage of an electrically driven film camera

Claim 1

IN AN ELECTRICALLY DRIVEN CINEMATOGRAPHIC CAMERA AN ELECTRIC DRIVING MOTOR FOR OPERATING SAID CAMERA, A BATTERY SUPPLYING CURRENT TO SAID MOTOR, AN EXPOSURE CONTROL SYSTEM INCLUDING A PHOTOELECTRIC CELL, A GALVANOMETER ENERGIZED BY SAID PHOTOELECTRIC CELL IN DEPENDENCE UPON THE LIGHT CONDITIONS OF AN IMAGE FIELD, A SENSTIVITY REGULATOR IN THE CIRCUIT OF SAID GALVANOMETER ADJUSTABLE IN ACCORDANCE WITH THE FRAME FREQUENCY OF SAID CAMERA AND CONSIDERING SAID FRAME FREQUENCY OF THE CAMERA IN THE RESULT OF EXPOSURE MEASUREMENT, A SWITCH, SAID SWITCH IN ONE POSITION CONDUCTIVELY CONNECTINGSAID GALVANOMETER CIRCUIT INCLUDING THE SENSITIVITY REGULATOR WITH SAID BATTERY FOR CHECKING THE BATTERY VOLTAGE, A MASKING CAP DETACHABLY MOUNTABLE IN FRONT OF SAID PHOTOELECTRIC CELL TO COMPLETELY DARKEN THE LATTER, SAID SWITCH BEING ARRANGED ON SAID CAP, PLUG CONTACTS CONDUCTIVELY CONNECTING SAID SWITCH AND THE BATTERY CHECKING CIRCUIT UPON MOUNTING SAID CAP IN FRONT OF SAID PHOTOELECTRIC CELL, THE DEFLECTION OF SAID GALVANOMETER DEPENDING ON THE ADJUSTMENTS OF SAID GALVANOMETER SENSITIVITY REGULATOR ACCORDING TO DIFFERENT FRAME FREQUENCIES, THE GALVANOMETER DEFLECTION ATTAINING THE SAME VALUE FOR ALL FRAME FREQUENCY ADJUSTMENTS IF THE BATTERY SHOWS THE RESPECTIVE MINIMOUM VOLTTAGE REQUIRED FOR OPERATING SAID CAMERA AT THE FGRAME FREQUENCY ADJUSTED ON THE GALVANOMETER SENSITIVITY REGULATOR.