[sdiy] CA3046 Heater / Substrate Question

[Nils Pipenbrinck]

On 05/05/2016 09:40 PM, Nils Pipenbrinck wrote:
>
> I doubt this is the reason. I replaced Q2 by a non-array transistor
> (2N3904) and all the strange behaviour just goes away.
>
> Obviously the isolated Q2 doesn't help the heating, but the electrical
> difference between the array transistor and the 2N3904 that I've used is
> the common substrate. Not much more.

Argh! Q3, not Q2.


Btw, since the expo-converter is not directly influencing the heater I 
can for now just fake and use one side of the transistor pair for 
heating. That way I'll at least be able to find out how much difference 
it would make. If it's worth it I'll find a way to make it work.

Best,
Nils