Re: Solve Simple Relationship

On 8/27/21 2:17 PM, José Abílio Matos wrote:
> On Friday, 27 August 2021 16.09.33 WEST Thomas D. Dean wrote:
>> I have a voltage divider I want to calibrate. I tried this by exchanging
>> the resistors and measuring the resultant rfesistance.
>>
>> 1.6516 = 3.3 * R1 / (R1 + R2)
>> 1.6484 = 3.3 * R2 / (R1 + R2)
>>
>> R1 is around 1005 ohms
>> R2 is around 1003 ohms
>>
>> I think this is simple.  But evidently, it is beyond me.
>>
>> Tom Dean
> 
> As others said your equations are the same, that is
> 
> 1.6516 = 3.3 * R1 / (R1 + R2) <=> 1.6484 = 3.3 * R2 / (R1 + R2)
> 
> So you do not have 2 but just 1 equation.
> 
> Note that 1.6516 + 1.6484 = 3.3.
> 
> So you really need another equation to resolve this problem. :-)
> 

Yes, I saw the relationship between the coeffs. And, the two equations 
are not independent, implicit plot shows they are the same line. I 
should have done this first.

Thanks for all the replies.

Tom Dean


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