Electronics usually have an environmental rating indicating the temperature range and humidity conditions in which they can be used. In most cases, they are only suitable for non-condensing conditions, but it isn't too difficult to source appropriate components that will handle 100% non condensing. In that case, your environmental controls need only keep the cabin humidity below 100%. Where feasable, you can protect components within an enclosure. All enclosures will have an IP rating, and IP65 or better will protect against atmospheric moisture. "Potting", or encapsulation, is typically done with epoxy compounds, and a variety of these are available depending on the desired thermal conductivity, opacity, etc. Epoxy encapsulation is very effective at making a component submersible, but will probably make it a single-use non-maintainable item. Where you need maintenance access, you can immerse components in a dielectric oil, which may be in an enclosure which is pressure compensated or not depending on if it is within the passenger compartment. The oil will protect them from moisture, but is a messy solution which is only really desireable if other options are unsuitable. Many dielectric oils are available - for submersible use, you should probably avoid a petroleum based oil which may create toxic atmosphere in the event of a leak or combustion.
-Sean
On May 29, 2009, Jens Laland <laland@artematrix.org> wrote:
Hi...
I wonder if anyone could share their experience with condensation in
relation to electrical systems inside small personal submarines.
My main concern is (periodic) failures due to moisture inside electronic
circuits, and how can we minimize those problems in home-built equipment?
I have discussed this with David, and he told me his view on "potting"
(something I will actually try out with a computer, ie. submerge it in oil).
However, I'm not quite sure what do with the various electro-mechanical
components such as rotary switches, etc.
What I do know (from studying various midget submarine operations during
World War 2) is that those guys considered the moisture/condensation to
be a major problem in relation to electric switch gears.
Having said this, I still think Frank is right when he says it's not a big
problem if your diving a K boat and staying down for an hour or less.
This is probably also more true in a milder climate than we normally have
here in Norway.
Best regards,
Jens Laland
************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003. Your email address appears in our database
because either you, or someone you know, requested you receive messages
from our organization.
If you want to be removed from this mailing list simply click on the
link below or send a blank email message to:
removeme-personal_submersibles@psubs.org
Removal of your email address from this mailing list occurs by an
automated process and should be complete within five minutes of
our server receiving your request.
PSUBS.ORG
PO Box 53
Weare, NH 03281
603-529-1100
************************************************************************
************************************************************************
************************************************************************