Patent ID: 9255776
Filing Date: 2016-02-09
CPC Classification: F42B,G01P

Claim Text:
1. In a gun tube having a defined longitude and a defined muzzle edge and a round of ammunition which is fired through said gun tube to exit past said muzzle edge, a round exit velocity measuring sensor to determine muzzle exit velocity of said round, said velocity measuring sensor comprised of: a planar, air coil transformer attached longitudinally to the side of said round, comprised essentially of a primary coil wire and a secondary coil wire having output terminals thereon, and wherein the primary coil wire comprises several turns in a loop that surrounds the secondary coil wire, so as to create an approximately uniform magnetic field throughout the secondary coil wire, and wherein said secondary coil wire comprises multiple twists, so as to create numerous loops of alternating orientation in said secondary coil wire, wherein the loops proximate the ends of said secondary coil wire are smaller than the other loops, and the sensor further includes: a current driving electronic circuit to drive a current in the primary coil wire; a measuring and conditioning electronic circuit to measure and condition the voltage signal at the output terminals of said secondary coil wire, and; an electronic signal processor that determines the muzzle exit velocity from the measured voltage signal at said secondary coil wire output terminals.