The sealing of electronic components... what your describing is called
potting... I highly recommend you stay far, far away from potting. It's an easy
way to demonstrate waterproofing but as a solution to a real-world everyday use
application it's a PITA to work with if you ever need to get back at the
components you potted.
There are indeed waterproof connectors for every cable type I've ever heard
of (and some I haven't), so long as you don't intend to decouple underwater you
can use these for cable connections.
Waterproofing ICs and PCBs should be handled by utilizing small preasure
cans that are 1atm designs with thru-hull sockets for the above
waterproof connectors.
Oil compensating is iffy at best, sometimes it works, sometimes it
doesn't... remember some ICs have little pockets of air in them and are very
sensitive to any change in resistance. Sometimes those air gaps are specificly
meant to arc, so the old comment of "non-conductive oil will insulate" is a
wash.... you want some things to arc if they are designed to.
ICs are delicate, (Comparitavely) treat them like you would glass objects
when designing for harsh environments.
----- Original Message -----
Sent: Wednesday, January 10, 2007 11:39
AM
Subject: Re: [PSUBS-MAILIST] basic design
help
I have reached a point in my initial design and sure would
appreciate a few basic questions answered. From this point
on I will be doing serious modeling, and really would like
the first attempt to be really stupid.
First I am planning on normal propane shaped pressure hull
power will be from ambient trolling motors.
an outer hull will be built for resistance as I want to
explore large areas of Lake Superior, speed will be
a large consideration. Working depth 400-500 ft fw
pressure hull design to have crush depth of >1500
First I will be using control surfaces for cruising.
I am planning on using hydraulic cylinders to operate
these with an on demand hydraulic electric pump.
The cylinders will be wet with hydraulic hoses thru
hull for control valves. Am also looking at a basic
mechanical arm using hydraulic cylinders.
Electrical components, can I seal in liquid acrylic
to withstand pressure and can the wires be sealed
with the same acrylic encasement, or do they need to be water
proof connectors.
I am planning on multiple fish finder sonars, and probably one
of the new fish finder side scan sonars. Will the transducers
epoxied to the hull handle these depths with out added
acrylic type reinforcement.
I also would like to tow an antenna on the surface for
GPS guidance and radio communications. Is this a
pipe dream, has it been done.
Is humidity a problem inside the hull during dives
also I will be operating in a constant water temp
of 47 degrees F do I need heat
Well that sure is enough questions. These are my hold
ups at the present to continue with my design. I want
to thank everyone for assistance so far. I do not think
I would be able to accomplish my dreams without
all of you
Thank you very much
Dean Ackman