New(?) ideas for the new year

[Martin Czech]

> The other thing is: I calculated a method of temperature compensation with
> cheap negative tempco resistors. (Those who look similar to ceramic caps)
> Most of them have a negative exponential behaviour, with a tempco of -4% / deg

Mhh, I bought some thermistors a while ago (looking like a nut&bolt, I
think they where for motor protection etc. and also "cap" like) and
then I put them into a thermostream.  Since these are semiconductor
elements (like all cheap tempco stuff) the R/T behaviour is very
nonlinear. A "tempco" of -4%/K will only be valid at one temperature,
the "tempco" will decrease with temperature.  In a limited range of
temperature it may be possible to lower the overall sytem error.  These
thermistors have large tolerances for "inital" resistance, i.e.
resistance say at  25C. This would mean to adapt the whole network for
the right scale AND for the right tempco. This could turn out a bit
too difficult for DIY, since you need some kind of temperature chamber.

It is doubtfull if the proposed method will compensate temperature
errors, I feel they might even get worse.

m.c.

------------------------------------------------------------------------
m.c. has made it finally:  3 CDs out now; 72 min. minimum; "1"
(1994-1995),"2" (95-96),"three" (96-97); experimental stuff; mostly
Eimert/Stockhausen style; but also modern popular style