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Full Version: Re: The lost formula
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We don't know what we don't know.

Regards,

John

If anyone understands the meaning of this thread, I would like to know.

Seems to me like just a question of curve fitting.

A thermistor is an electronic device whose resistance changes with temperature in a predictable, albeit nonlinear, way.

See:http://www.vishay.com/doc?29053

I'm guessing the OP used to have a simple equation to approximate a particular thermistor response at one time and lost it.

Thanks for responding, Norman.

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A thermistor is an electronic device whose resistance changes with temperature in a predictable, albeit nonlinear, way.

I'm guessing the OP used to have a simple equation to approximate a particular thermistor response at one time and lost it.

That much I got.

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On reading something everyone impress it on the matrix of "what they know". There can be nothing new under the sun, everything that can be learned has always been learned. You miss a lot of information that way. The impact of what I wrote is that there is a simple accurate method not disclosed by usual methods. Read the message with an open mind, your brains won't fall out.

Sam

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things which have been (very) tedious in the past may be far easier nowadays and become even easier in the future, caused by new insight or just compilations of older insights. This process goes on and on...

Walter

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We don't know what we don't know.

John

The rest not so much.

I think I had my high pass filter on and didn't absorb that part of the thread ;-/

Martin,

let me explain. As far as I understood the OP, he

• had found a simple method decades ago describing the electrical behaviour of a thermistor
• had used something like experimental math (or call it trial and error) for his finding since he had known no other way then
• can't find it again but doesn't want this knowledge getting lost
• keeps pointing us to this therefore.
I admit I don't know for sure what the OP wants us doing. So my answer could have been like John's, but I didn't want to leave an old man out in the rain. Thus I thought a bit and guess:

If that behaviour is of practical relevance, it was solved in the time between - or it can be modeled easily by some brute force fitting algorithm using the tools available today, which where beyond imagination decades ago. So the OP's problem is most probably solved now either way by the advancement of science ... dona eo pacem!

HTH. I'm most willing, however, to delete my two postings in this thread if they will cause any trouble whatsoever ...

Walter, I think I've got it now. Thanks for your help.

No need to delete anything.

I think I probably started adding 273 to the C temperature and found that was not quite the right slope and adjusted from there. I'll give it a try through programming and see what happens. I know it was dirt simple, probably a temp add-on and a normalizing factor to suit the particular resistance thermistor. Sam

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If anyone understands the meaning of this thread, I would like to know.

42.

Now that explains it!