Variable electronic flash light equipment

Claim 1

An electronic flash apparatus for outputting a selectively variable discharge illumination, comprising: a flash lamp; a power source; trigger means operable for causing an illumination generating discharge of said lamp; a main capacitor disposed in parallel connection to said lamp and said power source for storing a primary electric charge and for supporting illumination-generating discharge of said lamp upon operation of said trigger means; at least one circuit disposed in parallel connection to said main capacitor and said lamp and comprising a series-connected silicon controlled rectifier and secondary capacitor, said circuit being actuatable for selectively storing a secondary electric charge in said secondary capacitor; and selectively operative switch means for actuating said circuit to cause a secondary electric charge to be stored in said secondary capacitor for application with said primary charge to said lamp upon operation of said trigger means, such that the electric charge available for supporting discharge of said lamp may be varied from that normally provided by said main capacitor by selective actuation of said circuit to thereby increase the amount of illumination produced by said lamp by an amount corresponding to the electric charge stored in said secondary capacitor, and such that no electric charge is stored in said secondary capacitor absent actuation of said circuit to thereby conserve the capacity of said power source and promote efficient operation of said apparatus for flash lamp illumination.