RE: [PSUBS-MAILIST] speedo

Guys!!!! These would work with a bit of additional circuitry to provide and interface to them… like a PLC/Arduino/Microcontroller… they are used in autonomous underwater vehicles as well as cars,boats and planes (all autonomous)

http://www.sparkfun.com/commerce/product_info.php?products_id=9956

3 Axis Accelerometer

3 Axis Gyroscope and Accelerometer

http://www.sparkfun.com/commerce/product_info.php?products_id=8656

http://www.sparkfun.com/commerce/product_info.php?products_id=8507

Compass Modules with tilt compensation

http://www.sparkfun.com/commerce/product_info.php?products_id=418

3 axis Magnetometer evaluation kit

http://www.sparkfun.com/commerce/product_info.php?products_id=8147

Single axis Magnetometer

Stew

From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Alan James
Sent: Monday, 1 November 2010 12:43 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] speedo

David,

In hindsight ignore the bit about a current indicator. If you were being carried along in a

10 knot current you would be flowing with the water & the indicator would

hardly indicate.

Alan

----- Original Message -----

From: Alan James

To: personal_submersibles@psubs.org

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 -----

From: David Bartsch

To: personal_submersibles@psubs.org

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 -----

From: David Bartsch

To: personal_submersibles@psubs.org

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