www.piclist.com/techref/power.htm?key=voltage

Thanks for the input on this one. For your info, after some headscratching and a lot of paper, here's

the best answer I've got to, and verifed correct with Excel

<use fixed pitch font>

Given a bridge : Vin

+----+

R1 R2

+----|--- Vout (differential)

| +---

R3 Rx

+----+

GND

Calculate Rx given V, V=Vout/Vin

R2

Rx = ------------------

R1+R3

----------- -1

R3-V(R1+R3)

For my case, where R1=R2, we can also say R2=R2=1 as R3 and Rx can be

scaled to compensate.

This then simplifies to

R3-V(1+R3)

Rx = -----------

1+(V(1+R3))

And can be coded as

N=V*(1+R3)

Rx=(R3-N)/(1+N)

..which shouldn't take too much code, even in C! - any improvements

welcome, though!

Now to figure out where all the fixed points need to go...!

--

http://www.piclist.com hint: The list server can filter out subtopics

(like ads or off topics) for you. See http://www.piclist.com/#topics

See also: www.piclist.com/techref/power.htm?key=voltage