Sequencing static electronic flashing circuits for photoflash lamp array

Abstract

Abstract A SEQUENCING STATIC ELECTRONIC FLASHING CIRCUIT USED WITH A DISPOSABLE ARRAY OF N FLASH LAMPS (OR FLASHBULBS) OPERATES WITHIN SEVERAL MICROSECONDS TO FLASH ONE LAMP IN SEQUENCE EACH TIME THE CIRCUIT IS ENERGIZED IN TIME RELATION TO THE OPENING OF A CAMERA SHUTTER, CAN BE FABRICATED COMPLETELY AS A MONOLITHIC OR HYBRID INTEGRATED CIRCUIT, AND BY-PASSES OPEN-CIRCUTED LAMPS. EACH FLAHS LAMP EXCEPT OPTIONALLY THE FIRST IS IN SERIES WITH A SOLID STATE SWITCHING DEVICE SUCH AS A GATE CONTROLLED THYRISTOR OR A TRANSISTOR. A D-C LOGIC SEQUENCHING CONTROL CIRCUIT, IMPLEMENTED WITH CONSTANT VOLTAGE DROP MEANS AND LOGIC TRANSISTORS, REQUIRES AS CONDITIONS FOR TURNING ON A SWITCHING DEVICE THAT THE PREVIOUS DEVICE BE CONDUCTING AND THAT THE VOLTAGE ACROSS THE PRECEEDING LAMP TERMINALS EXCEED A THRESHOLD VOLTAGE, WHEREBY ALL PREVIOUS CONTROL CIRCUIT PATHS ARE CONDUCTING. CURRENT OR LIGHT SENSING OPERATES A LOCKOUT TO DE-ENERGIZE THE SEQUENCING CONTROL CIRCUIT TO PREVENT MULTIPLE FLASHES, AND IN ANOTHER EMBODIMENT THE SEQUENCING IS INITIATED BY AN EXTERNAL PULSE AND THE CIRCUIT IS ENERGIZED ONLY DURING THE DURATION OF THE PULSE. THE START OF SEQUENCING AFTER ENERGIZING THE CIRCUIT AND DE-ENERGIZATION THEREOF INDEPENDENT OF THE SHUTTER ACTUATED SWITCH CAN BE CONTROLLED EITHER BY MODIFICATIONS WITHIN THE SEQUENCING FLASHING CIRCUIT OR BY EXTERNAL TIMER CIRCUITS THAT OPERATE A STATIC SWITCH.

Inventors

• 👤 Donald L Watrous
• 👤 Paul T Cote

Bibliographic Details