two excimer lasers have individual pulsing circuits each including a storage capacitor which is charged and then discharged through a pulse transformer to generate an electrical pulse , which is delivered to the laser to generate a light pulse . the time between generation of the electrical pulse and creation of the light pulse is dependent on the charged voltage of the capacitor . the capacitors are charged while disconnected from each other . the generation of the electrical pulses is synchronized by connecting the capacitors together for a brief period after the capacitors are charged to equalize the charging voltages . the capacitors are disconnected from each other before they are discharged .