Re: How to proximity fuses work in missle warheads or balistic shells

Doug, That's a good question. I can't tell you how the latest fuzes work, 
but I can give you the basics. First of all, a fuse is a device for 
communicating fire. A fuze is a device used to ignite and explosive charge.
The spelling is important.
Proximity fuzes were developed after the second world war, when many 
improvements were made to the U.S. arsenal. The first proximity fuzes were 
of differing designs, including timed fuzes which were activated when the 
round was fired and pressure fuzes, which operated like a barometer.
The reason behind their development was simple.
An explosive, if it is not shaped like a cutting charge, will expand in 
all directions, a sphere. If the bomb hits the ground one half of the 
energy will be wasted into the ground, making a crater.
If the weapon is exploded before it hits the ground, more than 80% of the 
energy is directed outward, causing a great deal more damage.
These days fuzes are of electronic design, based on the pressure fuze 
concept and being minutely adjustable or they are controlled by the firer, 
being detonated when the weapon has reached a desired location.
Modern fuze designs are military secrets, but you could probably figure it 
out by deduction.
The funny thing is, many millions of bombs were dropped with contact fuzes 
that set them off when they hit the ground. These bombs did not need 
fuzes. Three hundred pounds of RDX or Napalm tendtoexplode when you drop 
it from five thousand feet at four hundred miles an hour, even if it hits 
jell-o.