Cypres Firing Method/Sequence

[Bazza 0]

I have done a search for info on the topic below. If I have missed something please accept my aplogies now and point me in the direction.
I have heard a couple of different accounts of how and when a Cypres fires. Some have suggested that a 'count down' starts and the unit becomes 'armed'. After a certain point if the algoritim conditions still exist (seven parameters through the one sensor?) after the arming sequence and at the proper altitude the unit fires.
Yet another version, and the one I tend to subscribe, is that the software algoritim is simply 'pass/fail' and will fire if the 'fail' parameters occcur at 750 feet above recognized ground level.
Can anybody shed some technical light on when and how the cypres software activates the hardware?
Thanks,
Baz

[Reginald 0]

I’ve heard the countdown theory too. I personally can find no evidence to support it (I've done a LOT of research on how a cypres works) and it does not make sense to me anyway. The “computer” is doing the calculations fast enough there is no need for a “countdown”. What purpose does a countdown serve? None that makes any sense to me. I personally believe it is a skydiver myth…

"We've been looking for the enemy for some time now. We've finally found him. We're surrounded. That simplifies things." CP

[FrogNog 1]

The countdown is not for the computer, it's for the powering of the cutter. The battery is zinc-air, which is good at supplying modest power requirements for a long time. To ensure proper operation, the cutter requires a big bite of power for a short time. So at a certain point the computer decides it needs to spend some time sucking power out of the battery into an intermediate pool from which it can generate the fast cutter firing burst.

This is all my understanding and I make no claim it is correct in part or whole.

-=-=-=-=-
Pull.

[EvilLurker 2]

Most likely it closes the power source to a capacitor ahead of time and waits for the "fire" parameter to be satisfied, then connects the capacitor to the cutter. That would make sense, it's similar to a camera strobe system, if so.

[mjosparky 4]

If you are going too fast, 78 fps, too low, 750 feet, the cutter goes bang.

Sparky

My idea of a fair fight is clubbing baby seals

[Samurai136 0]

78 MPH (115ft/sec) at 750ft AGL is the activation criteria.

Ken

"Buttons aren't toys." - Trillian
Ken

[sundevil777 102]

An earlier thread about the explanation of the Vigil logic sounded like it involved a constant prediction of the time remaining in freefall.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am