Patent ID: 6456797
Filing Date: 2002-09-24
Classification: G03B,H05B

Abstract:
An electronic flash unit comprising:a flash tube; first and second energy-storing flash capacitors, each one having an identical storage capacity which is sufficient to energize said flash tube for the same amount of flash illumination when either one of said first and second capacitors discharges its stored energy through said flash tube; a flash charging circuit charges each one of said first and second capacitors to their identical storage capacity; a charge switching circuit having mutually exclusive first and second states to alternatively connect each one of said first and second flash capacitors to said flash charging circuit, for the flash charging circuit to charge whichever one of said first and second flash capacitors that is connected to said flash charging circuit to its storage capacity, said charge switching circuit being biased to a neutral third state in which neither one of said first and second flash capacitors is connected to said flash charging circuit; and a controller changes said charge switching circuit to its first state to connect said flash charging circuit to said first capacitor when said first capacitor has discharged its stored energy through said flash tube and changes said charge switching circuit to its second state to connect said flash charging circuit to said second capacitor when said second capacitor has discharged its stored energy through said flash tube.