Tempcos was: Re: New(?) ideas for the new year

Martin Czech martin.czech at intermetall.de
Thu Jan 8 08:17:32 CET 1998


> How many people have actually built an oven to do this? I know about using
> multi-transistor ICs, using 2 for expo conversion and the other 2 for a
> heater/regulator circuit.  Since the charging capacitor will also change
> along with the temperature, wouldn't it be better (though harder) to build
> an oven and stick the expo converter and the charging cap (at a minimum)
> into it?  Or is this too much work for too little gain?
> Has anyone else thought of this or better yet attempted it?
> 

I heard the amateur radio people do this sometimes, put the whole
oscillator circuitry into the thermostat oven.  Using a transistor
array like CA4046 with build in heater transistor is a good idea, but
they seem to have poor matching, poor Hfe, poor Re, so they are not
suitable for large range exponential converters as stand alone
solution. If you use a DAC with autotune table, this could be corrected
however.

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





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