> -----Original Message-----
> From: piclist-bounces@mit.edu On Behalf Of Jinx
> Sent: Saturday, February 07, 2009 6:43 PM
>
> x
> |
> |
> x ?
>
> http://home.clear.net.nz/pages/joecolquitt/0-10mA_remote_lm335.gif

That is what I was thinking of _but_, now that I've looked more carefully at
your circuit I think I was all wet in my original suggestion. When I first
looked at the circuit for some reason I thought the output lead was directly
connected to an op-amp output. Now I see that the op-amp output is
de-coupled from the output wire with 147 ohms already.

My best guess now, without actually building the circuit, is that noise
originating from the zeners (especially the Vref zener) and/or output lead
is the culprit. Any noise from the reference Zener will be divided by ~2,
summed with the sensor signal then multiplied by 10 so, 5X the original
noise would be in the output.

Paul Hutch

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