[sdiy] CA3046 Heater TempComp

[jhaible at t-online.de]

patchell schrieb:
> http://www.silcom.com/~patchell/TAU1010/TAU1050.PDF
> 
>     This was a VCO sold about 20 years ago.  I redrew the 
> schematic, to make 
> it more readable...hopefully, it is accurate.

Nice circuit !
No opamp in the expo converter - And I thought you didn't like
discreet designs. (;->)
Looks EMS-inspired, but with an extra transistor for HFT (?).
I would have expected a zener diode instead of R11 - that's
how the EMS one works, at least, with Q1 doing the servo opamp's
job to keep the current thru the reference transistor constant.
Doesn't it need a capacitor from pin 1 to pin 2 of the transistor
array to prevent oscillations ? 

JH.