Risk Management Guide for Information Technology Systems: Recommendations of the National Institute of Standards and Technology

A triggering transformer having windings surrounding a photographic flash tube fires the latter when the transformer primary winding is energized by the closure of a switch. This switch closure also turns off a transistor which then unblocks a light sensitive integrator including an LASCR which receives the flash tube light by reflection. When the integrator has received a predetermined quantity of light, the LASCR turns on and energizes the primary winding of a second triggering transformer having windings surrounding a quench tube connected in parallel with the flash tube. This fires the quench tube which in turn extinguishes the flash tube.