Patent ID: 6735386
Filing Date: 2004-05-11
Classification: G03B

Abstract:
An electrical flash control apparatus comprising:a main capacitor that stores a charge for exciting a flash tube; a switching device having an ON state and an OFF state; a transformer, connected to said switching device, that generates a charging current for charging said main capacitor; at least two oscillators, including a first oscillator that outputs a first clock signal and a second oscillator that outputs a second clock signal; a CPU that receives at least one of the first clock signal from said first oscillator and the second clock signal from said second oscillator, outputs a switching signal to said switching device that repeatedly switches said switching device between the ON state and the OFF state; a first timer that receives the clock signal from the first oscillator and outputs a first timer signal; a second timer that receives the clock signal from the second oscillator and outputs a second timer signal; and a protection circuit that switches said switching device to the OFF state in response to either the first timer signal or the second timer signal, independently of the switching signal from said CPU.