Bernard,Target 22 X 28 X .oo9 in. paper, spring suspended from 4 corners.
Sensor, seismometer ( 3 in speaker with 3 US penneys glued to voice coil & 8 ohm : 1k ohm transformer ).
Sensor suspended horizontally from bottom center of target, light strikes regestered ( .2 V - pulse ) from all quadrents.
Moveng target back & forth gave no output.
I'd approach it a little differently. There is a pressure wave generated when the bullet strikes the small disk of paper and knocks it out of place. The energy in that pressure wave travels through the paper and through the air to the fingers and ears of our imaginary observer. It's a small amount of energy - the bullet is not slowed much - but my gut tells me the observer would certainly hear the impact and would probably feel it in the paper also. A sensitive instrument should be more than able to detect the impact.20.8 uS implies a frequency domain of 24,000 Hz
Awesome thanks.Frame - light weight wood, maybe 2 X 1/2 in held together with C clamps. Shaft has 2 in steel strap welded on to clamp frame to. 6 in crank fixed to shaft. Connecting rod connects crank to wheel so that 180 deg wheel rotation gives 90 deg. target rotation. Sensor hangs on bottom of parer target with aligator clip. Target held to frame with springs or rubber bands & alligator clips.
A gearhead motor turns wheel, single direction. Maybe something like a window lift motor, All Electronics, Cat# DCM- 467, 60 RPM, 12V 2.5 A no load. Torque ??
Another version of sensor uses a 64 ohm 2 " speaker with 2 gm wt glued to voice coil. no transformer required.
My power input will be 120V AC and 24V DC.There are less expensive solenoids, 24V & 12V, on All Electronics, Electronic Goldmine, & others.
Are you limited to just 24V?
You will need a pulse generator following comparator output with a relay driver ( 555 & FET ).
primarily .223 or 5.56 rounds, but I want to detect a wide range of munitions.no mention of caliber, a small pointed bullet like fired from an ar15 would make very little movement to the paper. the muzle blast might be greater, especially on a large area target.
If the drive pulse is short enough there is no reason why you could not use a 12V solenoid on a 24V supply. If necessary; just add a series resistor to limit the current.My power input will be 120V AC and 24V DC.
If I got a 12V solenoid, I would need to get a voltage regulator, which just adds yet another piece.
I will check out the solenoids on those sites.
No backing allowedCan you have a heavy metal backing, angled down to control ricochets? A sandbag beneath the back guard would trap the bullets. That way a round would certainly create a loud enough sound and/or vibration to detect.