in a system where a single power source battery is commonly used for the oscillation circuit of an electronic flash device and for another circuit , such as a control circuit for energizing a light source for a data recording for a given period of time , the operation of the oscillation circuit is interrupted by a semiconductor switching device in response to a firing of the flash tube of the flash device . the oscillation circuit interruption continues for a predetermined period during which the aforesaid another circuit is operated from the battery . to this end , the semiconductor switch may be controlled by a delay circuit .