a flashtube circuit includes a switch which in a first position regulates the storage over time of energy in a first energy storage device and in a second position allows the transfer of energy from the first energy storage device to a second energy storage device . a microcontroller receives the input voltage and then samples and digitizes it for input into a lookup table . the microcontroller repeatedly cycles the switch between flashes by controlling the time the switch is in its first position . the lookup table output provides the signal for determining the time the switch remains in its first position . the time interval from the last flash controls the time the switch is in its second position . the cycling of the switch is controlled accordingly such that the second energy storage device acquires the predetermined amount of energy for the flash just as the triggering circuit is initiated by the microcontroller . moreover , the microcontroller controls the switch in a way such that the time the switch is in its first position is maximized and the time the switch is in its second position is generally decreased relative to the time since the last flash . this helps to minimize the peak current drawn by the first energy storage device . in addition , the strobe light circuit is capable of determining if the input voltage is d . c . or is full wave rectified and controls the switch accordingly .