[sdiy] Temperature stable lin-exp converter with a CA3086or CA3046

[patchell]

Ian Fritz wrote:

>
> Isn't there also an issue with the higher source impedance of the scheme
> with the tempco in the voltage divider? I haven't put in numbers for this,
> but the 2k feedback scheme with about 500R for the output divider will act
> more like a pure voltage source.
>

    You are probably right on that score.

>
> BTW, weren't the old Q81's made with a high-resistivity alloy (Nichrome?
> Anybody remember?)

    I have a few 2K TelLabs Q81's.  I could probably disect one to find out....but
man, it is going to be difficult to motivate myself for just curiosity sakes...I
was always under the impression they used copper (copper has the required tempco),
but, I could be wrong.

>
>
>    Ian

--
 -Jim
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