Need 6 Volt DC dry contact activated timer.

[Rapidrob]

I built an accelerometer for a steel target that has a dry set of contacts that close when a bullet strikes the steel target. The closed contacts trigger an electronic flash that can be seen for over 1,000 yards. We try to video the flash and the duration of the flash is so short 50% of the time the electronic "shutter" does not see the flash. The trigger only allows one flash as it resets in one millisecond.
I would like to build a timer that will trigger the flash for two or three seconds then goes to sleep waiting for the next dry contact closure.( no voltage,there cannot be, just continuity)
6 Volts DC is supplied by a tractor battery,so current is not a problem.
The unit will be in the weather and need to be in an enclosure while in use.
The timer will be at least 50 feet away via a 22 gauge cable from the target and needs to be able to trigger the flash as fast as possible. Adjustable time to compensate for the delay of the capacitors in the flash to charge and fire.
So, what I need is: BANG! .......Clang!..flash,flash,flash,.... reset ready for next bullet strike.
Thank you for your help.

[KMoffett]

I am assuming that your current flash is a Zenon strobe...like a camera flash. You might be better off with a monostable circuit driving a bank of high power LEDs that can stay on continuously for a second or two.

Ken

[Rapidrob]

The light has to be seen in bright daylight from 1 km away in any weather condition.
If the LED's will be bright enough to be clearly seen,and the cost can be kept down,what do you propose as the circuit controlling the LED's and the timing?
Thank you for your reply.

[KMoffett]

OK with "The light has to be seen in bright daylight from 1 km away in any weather condition." I am not sure. I'm fishing here. Can you see a car headlight at that distance and under those conditions? Or a tightly focused automotive running light. Or maybe thinking of a laser that could be aimed at your camera. Something that can be "on" for a few seconds. Another would be three or four strobes that fire in sequence, with the hope of catching one.

Ken

[pebe]

Ken, if it's of any help.
I travel regularly on a long straight road which rises to a hilltop about a mile away. At that distance I can easily see cars' LED running lights when they come over the brow of the hill, even in bright sunshine.

[KMoffett]

Yeah, I was looking at "long throw" LED spot lights. http://www.lightforce.com/index.php?PID=46&cat=59#.VeCbA33e66E 1Lux at 997 yards. But we are talking $$$$.

And I don't have any direct experience with a LED lamps that might.

rapidrob, what strobe are you currently using?

Ken

[Rapidrob]

I'm using a 6VDC Metz Professional Camera Strobe that has an ASA 100 Film range of 100 feet. It is a beast. What this means is this is a very powerful flash.
Here is a short vid of the flash triggering at 800 yards. Extreme telephoto lens on camera.
https://www.youtube.com/watch?v=Bo3OrCkpBi8

[KMoffett]

OK, that tells us a lot. What model is the strobe, as METZ have a wide range. One thing that might be a factor in choosing an alternative, is the angle of that flash. It may be powerful, but if it has a wide angle of light distribution, only a small portion is actually aimed in you direction. A much less powerful light source with a very narrow distribution angle might work as well. There are a lot of powerful battery powered spot lights that might be acquitted. Your trigger to a LM555 timer and relay or MOSFET, to the spot light switch is no big deal. (I say while biting my tongue )

Ken

[Rapidrob]

It is a model 402. I have the diffuser off of the lens which makes it the long range beam.
Even at 25 feet when I trigger the flash with a rock,you see blue meat-balls for several seconds.

[KMoffett]

From what I can get from the 402's German manual (English versions cost $) the illumination field is 60°horizontal and 40° vertical. Though it appears bright to you at 25 feet, almost all of the light is directed away from your video camera. Only a minuscule amount of the light is directed toward the camera. This makes me think you could get by with one of the tightly focused, battery powered, hand held, spot lights. Maybe something like this: http://www.basspro.com/Browning-High-Noon-HandHeld-LED-Spotlight/product/14040214063613/ If it will illuminate things at "645 yards", your camera should be able the see it at 1000 yards. There are a lot of these types of spot lights on the market. Switching it on and off from your trigger would mean opening it up to bring out wires paralleling the switch.

Ken