PURPOSE: To prevent jamming of a film in a sound cinecamera, by not stopping a capstan motor but stopping only a film driving motor when the voltage of a power supply battery becomes lower than a reference voltage.

CONSTITUTION: A switch SW2 is connected to the inversion terminal of a comparator AMP1. When the switch SW2 interlocked with the release is turned off, a reference voltage VF from a constant voltage device REG is applied to the inversion terminal of the comparator AMP1, and a voltage VCC×R2/(R1+R2) is applied to the non-inversion terminal. VCC is the voltage of a battery E. If the voltage of the battery is lowered to make the voltage of the non-inversion terminal lower than the reference voltage VF, the output of the comparator AMP1 becomes low-level, and a film driving motor FM is stopped. Thus, since only the film driving motor is stopped when the voltage of the battery becomes lower than the reference voltage, jamming of a film is prevented.