ad_ward9 slamming everyone elses gear

Johnny Christensen

And that's a good thing, then I as a diver know a little more of what to watch out for. I like my inspiration, but I also like the firm knowledge that if I get complacent, there are ways that I have never thought about, that it will try to kill me.
It's so easy finding statements that all the people that have had accidents on the breather, where to blame for their own problems.
Thank god for the people that speak up, when they think there is something wrong.

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Wreckphotography from the cold north

PhilSiswick

This seems to be the most sensible approach to all of this. You can probably add this to all of the units out there in the market and fix a large number of the issues that Alex and others keep scaring the pants off me about for a small cost. Buying an aftermarket unit from another manufacturer also introduces a degree of independence that may be very useful.

OTOH, if they hadn't scared me witless, I'd never have come to this conclusion. Sadly, it won't lead to extra sales for Alex (or the people who OEM his technology from him), as it doesn't make me want to go down the nannying route.

Cheers,

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Phil

No comment on open circuit... it's an evolutionary dead end not really worth discussing here. Dave Sutton, 2007

I have always felt that the dive I am on is not nearly important as the dives I plan to be on the rest of my life. Tom Rose, 2007

www.hugsac.org.uk

rdmmdr

i started this thread because i perceived that Alex was one of the biggest nay sayer in the group. and that said i think that it should close now. the point is made. If you want to tell somebody they are doing it wrong, tell them how to do it right. if the gear is broken, how is it broken and how should i fix it?

rick

divetheworld

The more complex the design, the higher the goals and the longer it takes to get it working. I have often commented to Alex and the populous that I think his design goals are far beyond that which is required, but he has steadfastly stuck to his guns and that has to be respected.
When his rebreather is ready, I'm sure we will be the first to see it. I for one would like to be a test pilot on it, or see a well respected third party there just because I have always been a sceptic.
Alex has been around for some time now and even I have given him some stick in the past, but no more than I would anyone else on here. That is one of the great advantages of this forum that constructive critique is welcomed by all.
Alex' critical evaluations of other peoples kit is well known and has even led me to discuss new products with him to see if it can be pulled apart. Work to peoples strengths I say. It's called mutual respect.

Read his guff, structure an argument, then come back and present them.
You might disagree with alex's comments on Teledyne but I've got one here straight out of the bag that has a delayed response.

While your thinking about that, would you mind putting your toys back in the pram.



post script.

If I was alex, I wouldnt give this thread the consideration to respond.

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Mark Chase

I haven't forgiven Alex for getting me to run all round the Birmingham dive show looking for his CCR controller. It wasn't there despite him saying it was.

So I reckon he deserves a slagging

On the other hand he does give out some very very useful and interesting advice.

The other strange thing was no body seemed to know anything about the new head. i spoke to AP, John Bantin Louise, Kiss, the Meg boys, the BSAC CCR stand, Martin Farr, Kevin Gurr, etc etc. No one had herd of it or knew anything about it. Which i thought was a bit odd. A much hyped head like that you would have thaught was hot news.

ATB

Mark Chase

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I took my unit to the dive shop and demanded they bolt on every thing that would fit.

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Marat

I wonder if person who started this thread has ever met Alex Deas (AD_Ward9)?

I met Alex Deas when I was in army, when he was in camp getting amphibious vehicle, solders and explosives for a dive in far north of Russia in winter. He is a real diver.

He is Britain's top technologist. I looked him up from another post he did. If you search for "Alex Deas" Technologist on browser. It goes on for long time.

He has done what he said and published the Open Revolution design and a lot of other real data. It is like perestroika in diving!

RDMMDR, you probably do not like Alex because he guessed you worked in marketing when you said you make your engineers sweep floor. He also answered you on Cell thread when you did not know about ESD. I am electical engineer and the answer you got was right. You are arguing with Alex Deas because you are annoyed he is right but you pick technology as thing to argue. Not a good decision with him: you will lose that one.

rdmmdr

his esd answer was right if you assume that the ground plane is floating as in air but it does not work in a water environment. with common ground planes. ps to the ee,s out there how many of you have grabed a live 13.8 kv line, it tingles.

rick

Decodiver

Thank you all for bringing this back on track, the original post has been edited by the poster and I have removed quotes and remarks as to the specific language.

I for one recently woke up and saw a post I had made late the previous night whilst under the influence, I apologised and removed my thoughts and moved on.

Everyone of us is capable of posting all sorts of rudeness when we get our backs up.

What is nice on this forum is that people will review what they have said and will listen to others.

Only idiots never change their mind.

Thanks for getting back on track.

Cheers,

Dave Cooper.

Moderator.

Genesis

The ESD issue is an interesting one but let me posit something - how do you get ESD in a condensing humidity environment? C'mon guys, you know the answer to that one right?

Now open-cell charge buildup is certainly possible, BUT all the sensors out there specify a 10kohm shunt across the cell terminals in order to properly balance the temperature compensation circuit. Assuming that this resistor will fail open presents precisely the same risk as presuming that the series dropping resistor will fail shorted!

Is ESD protection of some kind necessary, given that cells are often changed in environments where discharge is possible? Yes. Is it hard to provide? No. Do you need to be able to source 100V on your inputs for an unlimited amount of time without damage? IMHO no. Can you design for that if you want? Sure, but as noted, it creates new problems you now have to solve (specifically, noise on the inputs requiring oversampling and averaging)

More importantly, will such a failure show up during pre-dive checks? IMHO, yes. The actual ESD risk in a closed, operating head with condensing humidity present is for all intents and purposes zero. The risk of a cell's internal load circuitry failing open exists but will show up during pre-dive testing; if it fails DURING a dive then that input will be pinned but at that point whether the amplifier channel is compromised or not is irrelavent since you can't change the sensor in the water anyway!

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NickK

How about ESD issue on absolutely "dry" unit? Let say during servicing or preparation for the next day diving. With lots of plastic and dry cynthetic materials, in most cases not static protected service benches, desks e.t.a.
it is very easy to understand how this can happened.
Also static not always kill components right away. Partially damaged components (usually semiconductors) can die over period of time, very bad if during the dive.

On "wet" unit, in high humidity environment should not be any ESD issue.

Nick