Re: Automatic buoyancy controls (was RE: Commercially available sub plans?)

[Ben Trumble <trumble@well.com>]

-- 

>Now, I've been thinking to myself abit about buoyancy control on an
>ambient pressure sub...  I've seen one sub that just kept itself           >neutral,no matter the depth, and used propulsion and small "wings" at  >either side to control depth.  With a system like that, you could 
>simply use a valve attached to a float - you have a pump constantly 
>pulling air out of the cabin, the higher the float on the valve(the 
>higher the water), the faster it puts air in, and as the internal 
>water-level lowers, so does the air input.  That way you maintain a 
>constant buoyancy, and a constant air flow.  What does everyone 
>think?  TTYL!

---
>Paul Anderson


I've wondered about using dual float valves myself?  But would you need
a pump to "pull" air out, or simply a valve to "vent" excess air?  On
the other side, if the water inside the bubble rises high enough to
trigger the float/switch valve #2 opens and releases air into the
cockpit until the float is seated again in the "off" position.  It
doesn't sound all that much more complicated than glorified toilet tank
engineering...if...and it's a big if...the valves and switches needed
could be bout off the shelf somewhere at a reasonable price. I found
that controlling the water level/bouyancy was almost impossible in my
lasy stab at an ambient boat.