Electronic flash gun with light dependant automatic control - has additional DC transformer windings to produce polarised impulse to shut off converter circuit transistor

摘要

The switching or circuit device for electronic flash guns has an automatic control of flash length depending on lighting conditions and utilising electronic components in particular a tube quench or thyristor adjacent circuit cut off for the flash tube and having devices which disconnect the power section of the device when the flash tube is being discharged, has one or more additional windings (23) in the core of the d.c. converter transformer which produces the capacitor charge to discharge the flash tube. These windings (23) are attached to the tube supply circuit and produce an impulse on the control electrode of the d.c. converter circuit transistor (4) of such a polarity that the transistor (4) is cut off having discharge of the flash gun powering capacitor.