Simulation Potentiometer Recommendation?

Hi,

I have a potentiometer on a simulation board used to simulate an A/D input
to a microcontroller-based product.

The pot is a Radio Shack $1.99 kind of model. It worked OK for about 2
months and now it is behaving erratically.

Application is low-current, strictly transducer stuff.

Can anyone recommend a better style of potentiometer to use that will behave
more precisely and last longer?

Constraints are:

a)Should be no more than 1-2 turn (it is operated manually, and a 10-turn
pot would be a pain).

b)Should be mechanically capable of accepting a knob (a screwdriver is too
much work).

Cost is no object. I'd go up to $25 if it would last a year.

Thanks, Dave.

try Midori America in L.A.

conductive plastic pots.

"David T. Ashley" wrote:
>
> I have a potentiometer on a simulation board used to simulate an
> A/D input to a microcontroller-based product.
>
> The pot is a Radio Shack $1.99 kind of model. It worked OK for
> about 2 months and now it is behaving erratically.
>
> Application is low-current, strictly transducer stuff.
>
> Can anyone recommend a better style of potentiometer to use that
> will behave more precisely and last longer?

Anything should be better than a Radio Shack. You are looking for
generic carbon pots, which come in various tapers, such as
logarithmic, linear, etc. Digikey should produce something.
Salvaging something from an older radio/tv volume or tone control
should do.

--
Chuck F () ()
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!

Hello CBFalconer,

> Salvaging something from an older radio/tv volume or tone control
> should do.

Those are actually the best. Those big old encapsulated monster pots. I
never had one of them fail on me so far.

Regards, Joerg

http://www.analogconsultants.com

On Mon, 8 Aug 2005 11:40:09 -0400, the renowned "David T. Ashley"
<> wrote:

>Hi,
>
>I have a potentiometer on a simulation board used to simulate an A/D input
>to a microcontroller-based product.
>
>The pot is a Radio Shack $1.99 kind of model. It worked OK for about 2
>months and now it is behaving erratically.
>
>Application is low-current, strictly transducer stuff.
>
>Can anyone recommend a better style of potentiometer to use that will behave
>more precisely and last longer?
>
>Constraints are:
>
>a)Should be no more than 1-2 turn (it is operated manually, and a 10-turn
>pot would be a pain).
>
>b)Should be mechanically capable of accepting a knob (a screwdriver is too
>much work).
>
>Cost is no object. I'd go up to $25 if it would last a year.
>
>Thanks, Dave.

The gold standard is conductive plastic over a wirewound element, but
if you don't have too many bits of resolution, a cermet pot should
work well enough for you, at least to 10+ bits of settability.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com