HIGH SPEED QUENCHING ARRANGEMENT FOR A FLASH DEVICE

摘要

A pulsed flash unit is provided with a photoelectrically controlled, interruptible thyristor gate whose transconductive path is connected in shunt with the flash tube for instantaneously quenching the light output from the flash tube when a predetermined quantity of emitted light has been monitored and integrated by the unit. A threshold-regulated transistor coupled to the output of the light integrator supplies a two-state control voltage to the control electrode of the thyristor so that the latter selectively provides a short and an open circuit across the flash tube.