Expo conv. heater (tomg et al.)

[Rene Schmitz]

At 13:13 30.01.99 +0100, jhaible wrote:
>>    I will most likely try Rene's method again and see if I have better
>> luck.
>

The only source of uncertainty is the cap in the servo loop of the
compensation ckt. Here you have to fiddle around with, sometimes values of
22pF are sufficient, 
and sometimes 1nF might be better.

>Yes. And in case it should be too nonlinear or too noisy (which I don't
>thik it
>is for general audio range VCOs), one could still use a transistor of the
>unheated
>chip to measure the momentary temperature, and then scale the CV with a
>linearized VCA.
>
>JH.
>
Yes that would work, but one would have to adjust the circuit so that the 
3300ppm/K are canceled. One could also glue an LM335 to the trannies, to
measure the temperature.
Personally I'm looking forward to do some experiments with devices like the
KTY 10
and KTY 81 PTC resistive(!) thermo sensors, and see if these are linear
enough for 
compensation. 
(But live open air gigs in northern Finland may be prohibitive with these...:)


Bye
 Rene

             ,   : (uzs159 at uni-bonn.de)
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