a second circuit configured to connect a power supply to the flash unit to actuate the flash unit upon {HEAD ~ operation} of the actuator to initiate the flash sequence for the flash interval, the second circuit configured to interrupt power to the flash unit subsequent to {TAIL ~ the operation} of the actuator to reset the flash unit for subsequent operation 
a second circuit configured to connect a power supply to the flash unit to actuate the flash unit upon { HEAD ~ operation } of the actuator to initiate the flash sequence for the flash interval , the second circuit configured to interrupt power to the flash unit subsequent to { TAIL ~ the operation } of the actuator to reset the flash unit for subsequent operation
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH