Bullet impact sensor help needed....
Bullet impact sensor help needed....
(OP)
Hi folks,new here. I have an unusual request for the experts.
I run a long range shooting club here in Albuquerque,NM. We have a need for a reactionary steel target that needs to sense a bullet impact. The normal kinetic energy that will be transferred to the steel plate will be in the neighborhood of 2,000 foot pounds traveling at 2,000 feet per second. I tried an acoustic sensor but were getting false target reactions due to the 180 dB sonic crack of the projectiles passing close to the target.
I'm thinking that a true impact sensor mounted to a thick steel block ( bullet resistant ) mounted to the rear of the steel target would sense the bullet impact. The target at the time of impact moves less than 3mm, however then energy transfer to the target is very high.
I want the sensor to close a relay to energize a motor drive that will withdraw the target from sight.
I'm not able to determine the resonate frequency of the steel plate upon impact,so I'm not sure if a simple glass brake sensor will work.
Thank you for any information.
Rob.
I run a long range shooting club here in Albuquerque,NM. We have a need for a reactionary steel target that needs to sense a bullet impact. The normal kinetic energy that will be transferred to the steel plate will be in the neighborhood of 2,000 foot pounds traveling at 2,000 feet per second. I tried an acoustic sensor but were getting false target reactions due to the 180 dB sonic crack of the projectiles passing close to the target.
I'm thinking that a true impact sensor mounted to a thick steel block ( bullet resistant ) mounted to the rear of the steel target would sense the bullet impact. The target at the time of impact moves less than 3mm, however then energy transfer to the target is very high.
I want the sensor to close a relay to energize a motor drive that will withdraw the target from sight.
I'm not able to determine the resonate frequency of the steel plate upon impact,so I'm not sure if a simple glass brake sensor will work.
Thank you for any information.
Rob.





RE: Bullet impact sensor help needed....
Fancy would be accelerometers and a sensing circuit that would trigger the motor mechanism if the peak acceleration of the plate was above some level (you would need to test to find the appropriate level).
Quick and dirty would be to tear open an old pinball machine, and take out the "tilt" switch. A similar device could be cobbled together from a microswitch and a spring-loaded pendulum.
In the really fancy category: If you google "bullet passage sensor" you will be led to several patents for acoustic sensors that not only sense bullet passage, but can also be used to compute the apparent hit location of the bullet. I know the USMC uses a system similar to these for some of its training ranges.
RE: Bullet impact sensor help needed....
RE: Bullet impact sensor help needed....
Not too sure what the interface is, but it is dead simple.
Cheers
Greg Locock
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RE: Bullet impact sensor help needed....
Thank you.
RE: Bullet impact sensor help needed....
RE: Bullet impact sensor help needed....
That way you won't need to have the sensor real near the target, in harm's way, and the frequency of the sonic boom ought to be singificantly different than the sound you get from impacting the plate.
Or you could simply require that the impacts be sufficiently centered that the plate is knocked down...
<grin>.
This is an interesting question; tell us what you end up doing.
RE: Bullet impact sensor help needed....
http://auto.howstuffworks.com/car-alarm2.htm
Ted