[sdiy] uA726, heated pairs...

[Tim Ressel]

Yo,

I use the heater circuit from AN299 on my VCOs. One
uses a 3046, the other uses a MAT04. It works as
advertised. I checked the circuit in an environmental
chamber so I could verify operation up to +40C.

--tr


--- Grant Richter <grichter at asapnet.net> wrote:
> > There is the little known National Semiconductor
> app note AN-299 (1986?),
> > where an LM3046 transistor array is used to
> provide a heated pair for a VCO.
> > 
> > I've tried it, but it seems to me that there was a
> change in chip manufacture,
> > and it doesn't work as advertised. The substrate
> pin is the problem.
> > 
> 
> Just a couple stray thoughts...
> 
> The ap note doesn't specify the pin out on the
> CA3046. You could probably
> get it to work by trying different combinations of
> heater and sensor
> transistor.
> 
> Also, the substrate connects to the most negative
> voltage used, in this
> case, it looks like ground and not -15V.
> 
> For a working example, see the Moog "Source" service
> manual which used a
> thermostated CA3046 for the expo-converter. The
> Serge NTO and PCO also use a
> heated CA3046.
> 


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