This is an electronics issue when you talk about the circuity which runs this technology.
BACKGROUND. Currently the US DOD is looking to develop air bursting (AB) projectiles (Mk310 projectile). The biggest problem with this technology is getting a projectile to air burst at the correct range (i.e. directly above the intended enemy personnel.) The muzzle velocity of standard projectiles will vary based upon a wide variety of environmental variables which would make using time as the AB trigger problematic. Northrop / ATK developed what they call a turns counting fuzing, which is based upon the assumption that a projectile will maintain the same revolutions per linear foot of flight as the twist rate found inside the gun barrel. If a gun barrel has a one turn per foot twist, then to get the projectile to explode at 1,000 feet, a turns counting fuze would need to detonate the fuze after counting 1,000 turns. I believe the way ATK counts turns in flight, is to use a hall effects type sensor to measure the earth's magnetic field. As a projectile spins in flight, the sensor will be rotating within the earth's magnetic field and it will produce a sine wave output with one cycle equal to one turn of the projectile.
ISSUE. In ATK's original patent (5,497,704 – MultiFunctional Magnetic Fuze), the inventor states “When the earth’s magnetic field is perpendicular to the spin axis (radial field), the tab-like portions of the core causes magnetic flux to alternate in direction through the coil thereby producing a sine wave voltage. As the alignment angle between the spin axis and the earth’s field vector direction changes, the sine wave voltage amplitude decreases with the cosine of the angle”. I need help in being able to explain this condition to non-technical people. It is doubtful that we are talking about whether we are shooting in different directions (i.e. north, south, east, or west) because a projectile that would only work based upon the direction you shoot would be worthless. My guess is where the inventor talked about the "sine wave voltage amplitude decreasing with the cosine of the angle between the projectile's spin axis and the earth's field vector direction"; this means that if a projectile is fired directly upward, then the angle between the projectile's spin axis and the earth's field vector would be 90 degrees and the sine wave amplitude would be zero; thus the fuze would not function. If this is correct, then an enemy could create a localized magnetic field which was 90 degrees to the earth's magnetic field and this would prevent a turns counting fuze from counting and essentially neutralize the fuze as long as it is within the localized artificial field.
THE QUESTION. I believe that DOD personnel are either complete idiots or have been bribed to continue funding any turns counting fuze technology. Any technology where the enemy could disable the fuze function, even for a short time, is a waste of our tax dollars and will kill our soldiers. If the field generator is next to the enemy, the fuze could not count or denotate near the enemy. If the field generator is between the enemy and the US forces, when the fuze passes through the field it would momentarily stop counting and when it restarts, it would end up detonating well past the enemy. To explain these issue to non-tech people, I need a graphic which shows the earth's magnetic field but I am not sure exactly how that would look like. If my graphics are off, people supporting this technology purely for money can get decision makers to ignore the danger here even if the basic premise is correct and this technology can be easily countered in order to kill Americans. I should explain that air bursting projectiles are desired as ammunition for US fighting vehicles to engage and kill enemy Anti-Tank teams whose sole purpose is to destroy US troop carrying vehicles; and most defense contractors are only interested in money and not how many US soldiers will died when their technology is easily defeated.
Finally, does anyone know where I can get a sensor which could measure the earth's magnetic field. I have tried calling around to find a hall effects sensor that could, but the reasonably priced ones I have found are supposedly not sensitive enough to measure the earth's field. I also do not want to have to pay hundreds or thousands of dollars for a demo sensor to do the work that our incompetent DOD research and development agencies should be doing. I have a machine shop and could easily make a demo which would show a spinning projectile generating a sine wave from the Hall Effects Sensor and then rotate the projectile to point up where the sine wave output would disappear. I could also include a magnetic field generator which when turned on would result in the sine wave also going to zero. If a newbie electronics person like me could figure out how to defeat this weapon system, I am sure the Chinese, Russia, Noth Koreans, and most Arab countries can do it too.
BACKGROUND. Currently the US DOD is looking to develop air bursting (AB) projectiles (Mk310 projectile). The biggest problem with this technology is getting a projectile to air burst at the correct range (i.e. directly above the intended enemy personnel.) The muzzle velocity of standard projectiles will vary based upon a wide variety of environmental variables which would make using time as the AB trigger problematic. Northrop / ATK developed what they call a turns counting fuzing, which is based upon the assumption that a projectile will maintain the same revolutions per linear foot of flight as the twist rate found inside the gun barrel. If a gun barrel has a one turn per foot twist, then to get the projectile to explode at 1,000 feet, a turns counting fuze would need to detonate the fuze after counting 1,000 turns. I believe the way ATK counts turns in flight, is to use a hall effects type sensor to measure the earth's magnetic field. As a projectile spins in flight, the sensor will be rotating within the earth's magnetic field and it will produce a sine wave output with one cycle equal to one turn of the projectile.
ISSUE. In ATK's original patent (5,497,704 – MultiFunctional Magnetic Fuze), the inventor states “When the earth’s magnetic field is perpendicular to the spin axis (radial field), the tab-like portions of the core causes magnetic flux to alternate in direction through the coil thereby producing a sine wave voltage. As the alignment angle between the spin axis and the earth’s field vector direction changes, the sine wave voltage amplitude decreases with the cosine of the angle”. I need help in being able to explain this condition to non-technical people. It is doubtful that we are talking about whether we are shooting in different directions (i.e. north, south, east, or west) because a projectile that would only work based upon the direction you shoot would be worthless. My guess is where the inventor talked about the "sine wave voltage amplitude decreasing with the cosine of the angle between the projectile's spin axis and the earth's field vector direction"; this means that if a projectile is fired directly upward, then the angle between the projectile's spin axis and the earth's field vector would be 90 degrees and the sine wave amplitude would be zero; thus the fuze would not function. If this is correct, then an enemy could create a localized magnetic field which was 90 degrees to the earth's magnetic field and this would prevent a turns counting fuze from counting and essentially neutralize the fuze as long as it is within the localized artificial field.
THE QUESTION. I believe that DOD personnel are either complete idiots or have been bribed to continue funding any turns counting fuze technology. Any technology where the enemy could disable the fuze function, even for a short time, is a waste of our tax dollars and will kill our soldiers. If the field generator is next to the enemy, the fuze could not count or denotate near the enemy. If the field generator is between the enemy and the US forces, when the fuze passes through the field it would momentarily stop counting and when it restarts, it would end up detonating well past the enemy. To explain these issue to non-tech people, I need a graphic which shows the earth's magnetic field but I am not sure exactly how that would look like. If my graphics are off, people supporting this technology purely for money can get decision makers to ignore the danger here even if the basic premise is correct and this technology can be easily countered in order to kill Americans. I should explain that air bursting projectiles are desired as ammunition for US fighting vehicles to engage and kill enemy Anti-Tank teams whose sole purpose is to destroy US troop carrying vehicles; and most defense contractors are only interested in money and not how many US soldiers will died when their technology is easily defeated.
Finally, does anyone know where I can get a sensor which could measure the earth's magnetic field. I have tried calling around to find a hall effects sensor that could, but the reasonably priced ones I have found are supposedly not sensitive enough to measure the earth's field. I also do not want to have to pay hundreds or thousands of dollars for a demo sensor to do the work that our incompetent DOD research and development agencies should be doing. I have a machine shop and could easily make a demo which would show a spinning projectile generating a sine wave from the Hall Effects Sensor and then rotate the projectile to point up where the sine wave output would disappear. I could also include a magnetic field generator which when turned on would result in the sine wave also going to zero. If a newbie electronics person like me could figure out how to defeat this weapon system, I am sure the Chinese, Russia, Noth Koreans, and most Arab countries can do it too.
