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At 01:56 PM 11/9/00 -0500, M. Adam Davis wrote:

>What you've told us so far:

>Two 9 bit numbers, A and B

>A + B is constant, so B is inversely proportional to A.

> There is a constant (A + B)

> This means their relationship is linear,

> Given A, B could be determined (and vice versa)

> (ie, A+B=512, 512-A=B, 512-B=A, etc if 512 is the constant)

I'm getting in trouble here because I'm not speaking precisely enough.

A + B = C

X is not a constant per se - its just that for a given set of components

and ambient temperature, A increases by the same amount that B

decreases. I find C when I've measured both A and B.

>So, your equation

>X = (remainder of) ( (A+B)/B )

>is actually X = B MOD Constant (MOD being the remainder of the division

>Constant/B)

This is where I'm not speaking precisely enough - I don't have a constant

that I can work with at compile time. I find (a+b) only after I've

measured both a & b during operation.

>So far, as I understand it, you are modeling a three terminal pot

>(terminals 1,2,3, with 2 being the wiper). A represents the resistance

>between 1 & 2, B the resistance between 2 & 3, so A + B is the total

>resistance of the POT, which is constant.

Its the best analogy I could come up with. The application is for

differential sensors, both resistive and capacitive.

As I mentioned in my first message, what I'm looking for is x = (remainder

of) (a+b) / b or, as you more correctly state: x = b MOD (a+b).

My first message said "I have 2 - 9 bit numbers that I need to find the

ratio of, where the ratio is expressed as a number from 00 to FF." I guess

what I failed to express clearly enough was that the ratio was "b" (top

part) and a+b (bottom part). Sorry for being imprecise.

dwayne

Dwayne Reid <dwayner.....planet.eon.net>

Trinity Electronics Systems Ltd Edmonton, AB, CANADA

(780) 489-3199 voice (780) 487-6397 fax

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