Open source, I see problems. Questions.

AD_ward9

Genesis! Your point is entirely political, so I will bow out.

The agencies do not cert 21/35 probably because you get a deco penalty on it much faster than using nitrox or air. Many a time I have seen dive boats in the USA full of OW or AOW divers, and one sees people pop up who have lost their weight belt, or "got scared", or just lost their buoyancy. I pick the USA simply because you are there, and frankly, it happens a lot less often in the UK because so many club dives here are deco dives. If the agencies adopted 21/35 trimix for OW or AOW divers, a lot more would get bent. My 2c.

Anyhow, this particular point is an agency issue rather than one for us design engineers to champion. It would be too controversial for us to take on, and we could be flogging a dead horse.

Cheers,
Alex

Genesis

Well, I bet you can tell what I think of the idea of giving someone a "cert" when they don't even have rudimentary buoyancy control (and yes, I know it happens all the time!)

My only point was that if you embrace a political view (and giving instructors the ability to set gas limits is doing so; you're endorsing an agency's view of "how it should be") then you have taken it up as your own.

I'd love to see this project be "apolitical" - but that means convincing you folks that lockouts are ill-advised..... Since it appears that decision's been made.......

AD_ward9

We do double up the injector, so you could run dual O2. That is not what we designed it for (we designed it to prevent an injector failing: ours fails shut normally), but that would work. You can have as many dil cylinders as you like.
The CO2 is a bit more complex. Flushes, loss of gas from the system, etc.
Changing dil: it does warn on high END. We took the view that rather than prompt for gas changes, allow the user to plumb in what they want, and if it is something unpleasant, then warn them. That way it is just "plumb and go".
Divers usually use the first set to come back on. If a cylinder gets low, the system warns, also if N2 is too high or PPO2 rises too high.
I do it the easy way, I carry monster size cylinders. Not seen anyone else go to that extreme though.
See comment on the O2. As to cost, it would be done by the user.
Be very glad you have a wife that prefers the first option over the second!
Will come. I am trying to get the FMECA out this week.
Analogue compasses are OK, but the earth magnetic field sensors are not. We use potted rare earth magnets.
[/quote]Again, thanks for a lot of thought in your email. I really need to get the FMECA out. It is my main objective for this week, but I have some commercial documents I need to clear from my desk first.
Cheers
Alex

AD_ward9

You convince two reputable agencies to run OW trimix, and we will enable 21/35 for those users.

Before you get your hopes up too high, think what you are asking an agency to support: OW deco diving. Any agency that supports that would lose the "reputable" sticker really quick.
Cheers
Alex

Genesis

Not any more than they're "supporting" it now. They all recommend against deco on an OW cert now but also are all aware there is nothing they can do to stop you from making those dives.

There is plenty of argument for using light helium mixes in the 100-130 zone when cost is a non-factor (as it is with a rebreather); the primary argument against it on OC is the price escalation .vs. "just how drunk are you are 110" debate.

BTW, your requirements are already met for hyperoxic to normoxic Trimix. GUE (and I believe IANTD) both have a "recreational triox" cert. I believe it covers up to 30/30. Both certs are explicitly intended for no-deco diving.....

Sounds to me like I met your criteria......

AD_ward9

Sorry I misread the meaning in your earlier post to include manufacturers.
Cheers
Alex

AD_ward9

If all FPGAs fail, the uP on each side still works.
The main hazard in an FPGA is self-configuration failing. The devices are configured in a manner which is self testing.
Quite a lot on this in the FMECA. I am trying to get it out asap. Not enough hours in day.
Cheers,
Alex

Genesis

Looking forward to it!

divetheworld

Isnt all this discussion a mute point?

You stated in one of the earliest posts on this thread that there will be an expedition model which has no restriction. So each person has a choice, restricted or unrestricted. So, if you dont agree with the philosophy, buy the expo model. Do I understand it right?

__________________

silent running

Thanks again Alex, for all the info on both threads regaurding your Rebreather design-Andy