M782 fuze

Fuze M782 - the Multi-Option Artillery Fuze (MOFA) is a multifunction artillery fuze used with high-explosive fragmentation (HE) 105 mm and 155 mm projectiles.

The fuze has four operating modes:

- variable time (VT),
- time (TIME),
- point detonating (PD)
- point detonating with delay (DLY).

The M782 fuze contains an electronic timing system that can operate from 0.5 to 199.9 seconds in steps of one tenth of a second.

The fuze is set with an inductive setter. During firing the power battery is activated and the microcomputer boots up. The microcomputer loads the firing data from the EPROM into one of its registers. The microcomputer verifies the validity of the firing data and starts counting time. The mechanical S&A safety is removed after the projectile has traveled a distance of 400 calibers.
The electrical arming time depends on the mode and the time set. If the fuze is set to point-detonating mode, the detonator fires when the impact switch closes its contacts. If the delay mode is set, detonation is initiated about 8 ms after the impact switch contacts close. If the time mode is set, the detonator fuze is initiated according to the user-programmed time function. If impact occurs before the set time, the impact switch closes and the detonator fires.

In variable-time mode, the microcomputer turns on the proximity sensor relay 4 seconds before the set time. The microcomputer ignores any signals during the first 200 ms while the signal processor stabilizes.
The detonator is activated when the microcomputer receives the fire signal from the signal processor.
If impact occurs before the proximity sensor gives a signal, the impact switch closes and the detonator fires.