[sdiy] A little OT, Begging a hand

[Jerry Gray-Eskue]

<<each in the hope that I can determine R1, R2, R3, R4 and R5 >>

If I am reading this corectly, what you really want to know is the value of 
the resistors but for some reason cannot measure them directly?  Where did 
the values (R1+R2+R3=K, about 600 ohms etc.) come from?

<< For reference, this is the equivalent circuit for a sensor I am working 
with on a music controller project.>>

If this is a sensor, it will be something other than a fixed value resistor 
network, is that what you meant by
<<R4 and R5 vary between about 1K and 500K>> ?



----- Original Message ----- 
From: "Veronica Merryfield" <veronica.merryfield at shaw.ca>
To: "synth DIY" <synth-diy at dropmix.xs4all.nl>
Sent: Tuesday, February 08, 2011 12:50 AM
Subject: [sdiy] A little OT, Begging a hand


>I wonder if anyone might be able to help me out on what I was hoping was a 
>simple problem.
>
> I have the following resistor network (ascii art follows so you'll need a 
> fixed pitch font selected)
>
> V1
> |
> \
> / R1
> \
> /
> |    R4        R6
> |--/\/\/\----/\/\/\----- Vout
> |          |         |
> \          \         \
> / R2       / R7      / R8
> \          \         \
> /          /         /
> |    R5    |         |
> |--/\/\/\--          |
> |                    V3
> \
> / R3
> \
> /
> |
> V2
>
> I can set each of V1, V2 and V3 to either +Ve, GND or OC independently, 
> although not all combinations are useful, and I can measure Vout. 
> R1+R2+R3=K, about 600 ohms. R1=R6 and R2=R7, R4 and R5 vary between about 
> 1K and 500K and R8 is fixed at 2K2 although this can be changed.
>
> I want to set a number of input combinations and measure Vout from each in 
> the hope that I can determine R1, R2, R3, R4 and R5 with some simultaneous 
> equations.
>
> My attempts have been a bit of a failure and I think I am missing 
> something so I was hoping someone here might be able to help me.
>
> For reference, this is the equivalent circuit for a sensor I am working 
> with on a music controller project.
>
> Veronica
>
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