Electronic Control Unit The electronic control unit is a solid-state electronic control unit in a sealed container. The electronic control unit controls all the functions of the bomb rack and have the capability of releasing stores at 35-millisecond intervals. The electronic control unit is disposable. If it malfunctions, replace it with a new one. Ejector Unit Assemblies The ejector unit assemblies used on the IMER and ITER are identical. The only difference between them is the internal configuration of the release linkage. The ejector units are configured for right-hand shoulder installation, left-hand shoulder installation, or centerline installation (fig. 10-10). Part number identifies them. The shoulder stations are attached to the adapter assembly by ejector unit attach blocks. The centerline stations are attached by ejector unit attach hangars. A IMER/ITER ejector unit (fig. 10-11) consists of a housing assembly equipped with integral wiring, a breech and ejector mechanism, store suspension hooks, a store sensing switch, two mechanical arming solenoids, an electrical arming unit, adjustable sway braces, and mechanical linkage driven by the breech or manual release lever to open the suspension hooks. The  suspension  hooks  are  spaced  14  inches  apart and are independently self-latching. There is a manual release  lever,  which  is  used  to  open  the  hooks  during ground operation. The safety stop lever is used to safe the ejector unit mechanically. Look at figure 10-12. It shows the locked and unlocked positions of the ejector unit  safety  stop  lever.  When  the  safety  lever  is  in  the locked  position,  the  hook  release  rod  is  physically blocked from rearward movement and prevents suspension hook release. If the hook release rod is not in the full forward position, the safety stop lever cannot be   rotated   to   the   locked   position.   A   store-sensing switch  is  located  under  the  forward  suspension  hook, and is actuated by the opening and closing of the hook. IMER/ITER Operational Description The   functional   description   of   the   IMER/ITER ejector rack is discussed in two categories—ejector unit mechanical operation and IMER/ITER electrical operation. EJECTOR UNIT OPERATIONAL DESCRIP- TION.—All ejector units on the IMER and ITER are operationally    the    same.    An    electrically    initiated gas-generating cartridge actuates the ejection mechanism.  As  you  read  this  section,  look  at  figure 10-13. It shows the mechanical operation of the ejector unit. When  a  store  is  loaded  onto  the  ejector  unit,  the store suspension lugs force the suspension hooks to the closed position. The suspension hooks are locked in the closed position by the over center position of the hook toggle levers. The link stops, located over each of the hook toggle levers, prevent the suspension hooks from opening until the cartridge is fired or the manual release lever  is  pulled,  even  if  the  safety  stop  lever  is  in  the unlocked position (fig. 10-13, view A). When   the   gas-generating   cartridge   is   fired,   the resulting  gas  pressure  moves  the  breech  aft.  The  aft movement  of  the  breech  also  moves  the  hook  release rod  aft,  lifting  the  toggle  hook  levers  from  the  over center   position.   The   cranks   are   forced   down.   This unlocks the suspension hooks (fig. 10-13, view B). 10-8 Figure 10-10.—IMER/ITER ejector unit locations.