----- Original Message -----
Sent: Monday, November 01, 2010 2:26
PM
Subject: Re: [PSUBS-MAILIST] speedo
Hi David,
I'll keep the idea percolating. I have some ideas; it
could be used with the rotary pot.
The beauty of the position sensor circuit (wich I didn't
design) is that the circuit can
be tuned by two pots to light the full range of LEDs
even though the magnetic potentiometer
might be used only through a small degree of
it's range. So it can be easily adapted.
It might be a good water current indicator. If you were
mid ocean with no visual reference &
you knew what your boat speed should be by experience,
& found that you were going faster or
slower according to the speedometer, then you could
calculate the current. That's providing the
current isn't coming from the side.You would probably
need another one for that.
I believe another Psubber was working on an
expensive system involving a computer & using
all sorts of data input to log their
progress.
Regards Alan
Original Message -----
Sent: Monday, November 01, 2010 1:07
PM
Subject: RE: [PSUBS-MAILIST]
speedo
Alan,
Being able to determine the
speed at which you are traveling while submerged when no visual aids are
there to help you would be of great importance to me. This idea you
mentioned would be a much desired device. I would like to encourage you
to undertake its development as the end product would be worth the
while.
I had considered a paddle that would be forced
against a spring to give a mechanical indication of speed but your idea
looks much better.
David Bartsch
From: alanjames@xtra.co.nz
To:
personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST]
speedo
Date: Mon, 1 Nov 2010 08:55:54 +1300
Hi David,
You've got me thinking on this speed indicator
idea.
On my projects page is the "Position sensor". I'm
using a rotary magnetic potentiometer,
but there is a linear magnetic potentiometer shown
also.
You could have a slider over the top of the linear
potentiometer, with a vane that is pushed
by water movement against a spring. The vain portion
has the magnet & as it slides further
along the potentiometer it changes the voltage wich is
registered on the circuitry also on
my projects page. You could have the speed indicated
by the LEDs as is, or output to a
panel meter. This could be calibrated in a swimming
pool by either adjusting the spring size
or tension, the size of the vain, or by adjusting the
display range with the pots on the circuit board.
Regards Alan
----- Original Message -----
Sent: Sunday, October 31, 2010 10:10
PM
Subject: [PSUBS-MAILIST] speedo
Can anyone describe how a speedo speed indicator system
works and would such a system be suitable for small submarines? Is'nt such
a system deployed on the R-300 Cliff?
David
Bartsch