Source Sealed Potentiometers?

Can anybody recommend a source of miniature multi-turn potentiometers,
protected to IP67 or 68 for a marine application?

Thanks.

JM

Hi John,

Have you considered ant other technology as Hall sensors ? Not as
straightforward maybe, but they keep working in harsh enviroments.

I'm using : www.contelec.de

Stan

> Can anybody recommend a source of miniature multi-turn potentiometers,
> protected to IP67 or 68 for a marine application?
>
> Thanks.
>
> JM

John Mianowski wrote:
> Can anybody recommend a source of miniature multi-turn potentiometers,
> protected to IP67 or 68 for a marine application?


IP 67 is flush water, IP 68 is under water.
You want to measure an angle ?
What is the angular speed of the sensor ?

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

StanV wrote:
> Hi John,
>
> Have you considered ant other technology as Hall sensors ? Not as
> straightforward maybe, but they keep working in harsh enviroments.
>
> I'm using : www.contelec.de
>
> Stan
>
> > Can anybody recommend a source of miniature multi-turn potentiometers,
> > protected to IP67 or 68 for a marine application?
> >
> > Thanks.
> >
> > JM

No problem using Hall effect sensors, but I need multi-turns.

Thanks,

JM

Rene Tschaggelar wrote:
> John Mianowski wrote:
> > Can anybody recommend a source of miniature multi-turn potentiometers,
> > protected to IP67 or 68 for a marine application?
>
>
> IP 67 is flush water, IP 68 is under water.
> You want to measure an angle ?
> What is the angular speed of the sensor ?
>
> Rene
> --
> Ing.Buero R.Tschaggelar - http://www.ibrtses.com
> & commercial newsgroups - http://www.talkto.net

I need to be able to survive immersed in fresh water for several
minutes. I think I might be able to get away with IP67.

I need to be able to measure an angle 0-360, & can't directly couple to
the shaft/axis of rotation. I can put a gear on the object to be
measured, & due to space constraints I need to reduce at least 5:1.

Angular speed would be slow, probably no more than about 30 RPM.

JM

John Mianowski wrote:

>> IP 67 is flush water, IP 68 is under water.
>> You want to measure an angle ?
>> What is the angular speed of the sensor ?
>>
>> Rene
>> --
>> Ing.Buero R.Tschaggelar - http://www.ibrtses.com
>> & commercial newsgroups - http://www.talkto.net
>
> I need to be able to survive immersed in fresh water for several
> minutes. I think I might be able to get away with IP67.
>
> I need to be able to measure an angle 0-360, & can't directly couple to
> the shaft/axis of rotation. I can put a gear on the object to be
> measured, & due to space constraints I need to reduce at least 5:1.
>
> Angular speed would be slow, probably no more than about 30 RPM.

Is cost an issue or are you able to look at synchro/resolvers as a means to
measure the angle. There are some around that, due to their construction,
are OK for immersion. The solution is more expensive than a pot for
measuring angle but is quite dependable.

--
************************************************** ******************
Paul E. Bennett ....................<email://>
Forth based HIDECS Consultancy .....<http://www.amleth.demon.co.uk/>
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-811095
Going Forth Safely ..... EBA. www.electric-boat-association.org.uk..
************************************************** ******************

Paul E. Bennett wrote:
> John Mianowski wrote:
>
> >> IP 67 is flush water, IP 68 is under water.
> >> You want to measure an angle ?
> >> What is the angular speed of the sensor ?
> >>
> >> Rene
> >> --
> >> Ing.Buero R.Tschaggelar - http://www.ibrtses.com
> >> & commercial newsgroups - http://www.talkto.net
> >
> > I need to be able to survive immersed in fresh water for several
> > minutes. I think I might be able to get away with IP67.
> >
> > I need to be able to measure an angle 0-360, & can't directly couple to
> > the shaft/axis of rotation. I can put a gear on the object to be
> > measured, & due to space constraints I need to reduce at least 5:1.
> >
> > Angular speed would be slow, probably no more than about 30 RPM.
>
> Is cost an issue or are you able to look at synchro/resolvers as a means to
> measure the angle. There are some around that, due to their construction,
> are OK for immersion. The solution is more expensive than a pot for
> measuring angle but is quite dependable.
>

I'd like to keep the cost down, for sure. I haven't found any synchros
or resolvers that can deal with multiple turns, & I don't have a way to
tell which turn it might be on after power-up/reset. A multi-turn pot.
would work very nicely, but all I've been able to find that are
immersable are pretty pricey (i.e. oil-filled, $US80 & up).

JM

John Mianowski wrote:

>
> Paul E. Bennett wrote:
>> John Mianowski wrote:
>>
>> >> IP 67 is flush water, IP 68 is under water.
>> >> You want to measure an angle ?
>> >> What is the angular speed of the sensor ?
>> >>
>> >> Rene
>> >> --
>> >> Ing.Buero R.Tschaggelar - http://www.ibrtses.com
>> >> & commercial newsgroups - http://www.talkto.net
>> >
>> > I need to be able to survive immersed in fresh water for several
>> > minutes. I think I might be able to get away with IP67.
>> >
>> > I need to be able to measure an angle 0-360, & can't directly couple to
>> > the shaft/axis of rotation. I can put a gear on the object to be
>> > measured, & due to space constraints I need to reduce at least 5:1.
>> >
>> > Angular speed would be slow, probably no more than about 30 RPM.
>>
>> Is cost an issue or are you able to look at synchro/resolvers as a means
>> to measure the angle. There are some around that, due to their
>> construction, are OK for immersion. The solution is more expensive than a
>> pot for measuring angle but is quite dependable.
>>
>
> I'd like to keep the cost down, for sure. I haven't found any synchros
> or resolvers that can deal with multiple turns, & I don't have a way to
> tell which turn it might be on after power-up/reset. A multi-turn pot.
> would work very nicely, but all I've been able to find that are
> immersable are pretty pricey (i.e. oil-filled, $US80 & up).

You stated that you could use a gear for reduction. The way resolvers are
usually used for keeping track of multiple turns of a shaft and how far the
shaft itself has gone would be to use two. However, as you have stated that
direct drive is not possible and you would be gearing anyway you could just
gear the synchro/resolver appropriately to gain the desired revolutions in
one turn of the synchro/resolver shaft. Naturally, the applicability of
this woul depnd on the accuracy and resolution you require of the
measurement.

We are all groping a little with such scant detail of the situation.Perhaps
a little more about the nature of your requirement here would help us help
you.


--
************************************************** ******************
Paul E. Bennett ....................<email://>
Forth based HIDECS Consultancy .....<http://www.amleth.demon.co.uk/>
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-811095
Going Forth Safely ..... EBA. www.electric-boat-association.org.uk..
************************************************** ******************

Paul E. Bennett wrote:
> John Mianowski wrote:
>
> >
> > Paul E. Bennett wrote:
> >> John Mianowski wrote:
> >>
> >> >> IP 67 is flush water, IP 68 is under water.
> >> >> You want to measure an angle ?
> >> >> What is the angular speed of the sensor ?
> >> >>
> >> >> Rene
> >> >> --
> >> >> Ing.Buero R.Tschaggelar - http://www.ibrtses.com
> >> >> & commercial newsgroups - http://www.talkto.net
> >> >
> >> > I need to be able to survive immersed in fresh water for several
> >> > minutes. I think I might be able to get away with IP67.
> >> >
> >> > I need to be able to measure an angle 0-360, & can't directly couple to
> >> > the shaft/axis of rotation. I can put a gear on the object to be
> >> > measured, & due to space constraints I need to reduce at least 5:1.
> >> >
> >> > Angular speed would be slow, probably no more than about 30 RPM.
> >>
> >> Is cost an issue or are you able to look at synchro/resolvers as a means
> >> to measure the angle. There are some around that, due to their
> >> construction, are OK for immersion. The solution is more expensive than a
> >> pot for measuring angle but is quite dependable.
> >>
> >
> > I'd like to keep the cost down, for sure. I haven't found any synchros
> > or resolvers that can deal with multiple turns, & I don't have a way to
> > tell which turn it might be on after power-up/reset. A multi-turn pot.
> > would work very nicely, but all I've been able to find that are
> > immersable are pretty pricey (i.e. oil-filled, $US80 & up).
>
> You stated that you could use a gear for reduction. The way resolvers are
> usually used for keeping track of multiple turns of a shaft and how far the
> shaft itself has gone would be to use two. However, as you have stated that
> direct drive is not possible and you would be gearing anyway you could just
> gear the synchro/resolver appropriately to gain the desired revolutions in
> one turn of the synchro/resolver shaft. Naturally, the applicability of
> this woul depnd on the accuracy and resolution you require of the
> measurement.
>
> We are all groping a little with such scant detail of the situation.Perhaps
> a little more about the nature of your requirement here would help us help
> you.
>

What I need to do is rotate what amounts to a
lazy-susan/turntable/camera mount (pan only). I need to rotate up to
360 degrees, but not continuous. The device sits on a bearing so there
is no center shaft that I might couple to. OD is 3". My plan is to
attach a gear (I've got that part worked out OK) to be driven by an
electric motor. What I need is some sort of position feedback. The
gear I've chosen for the turntable has 156 teeth with a pitch diamter
of 3.25". I figure that with a mating 32-tooth gear, I can attach a
5-turn pot. (ratio = 4.875:1, leaving a little travel at either end).
What I DON'T have, besides a shaft to couple onto directly, is space
for another 3.25"-dia. gear to keep the ratio of turntable to position
sensor at 1:1 or below, & I'd like to avoid using a multi-stage
reduction gear if I don't absolutely have to.

I also have to be able to survive immersion in fresh water for up to 30
minutes.

Thanks!

JM

John Mianowski wrote:
>
.... snip ...
>
> What I need to do is rotate what amounts to a
> lazy-susan/turntable/camera mount (pan only). I need to rotate up to
> 360 degrees, but not continuous. The device sits on a bearing so there
> is no center shaft that I might couple to. OD is 3". My plan is to
> attach a gear (I've got that part worked out OK) to be driven by an
> electric motor. What I need is some sort of position feedback. The
> gear I've chosen for the turntable has 156 teeth with a pitch diamter
> of 3.25". I figure that with a mating 32-tooth gear, I can attach a
> 5-turn pot. (ratio = 4.875:1, leaving a little travel at either end).
> What I DON'T have, besides a shaft to couple onto directly, is space
> for another 3.25"-dia. gear to keep the ratio of turntable to position
> sensor at 1:1 or below, & I'd like to avoid using a multi-stage
> reduction gear if I don't absolutely have to.
>
> I also have to be able to survive immersion in fresh water for up to 30
> minutes.

What sort of positional resolution (in degrees, or even in gear
teeth count) do you require? Something like a pair of leds for
tooth resolution, and a reset mechanism via a microswitch could
provide the position. The pair of leds can detect rotation
direction, and the whole schmeer should be immune to over-rotation,
unlike a pot. Counting the 156 teeth should give you roughly 2
degrees of positional resolution.

Your only worry would be the effect on the light path of the
immersion, which should not be excessive in fresh water.

--
Some informative links:
<news:news.announce.newusers
<http://www.geocities.com/nnqweb/>
<http://www.catb.org/~esr/faqs/smart-questions.html>
<http://www.caliburn.nl/topposting.html>
<http://www.netmeister.org/news/learn2quote.html>
<http://cfaj.freeshell.org/google/>