[volt-nuts] LTZ1000 project build

[Charles Steinmetz]

Poul-Henning wrote:

> Only thing to remember is that it also reduces air circulation in the
> box and therefore increases thermal gradients.

The starting point is a sensitive circuit, which I would put in a 
close-fitting, fully shielded box in any case.  So even if it weren't 
quasi-hermetically sealed, there would still be essentially no exchange 
of air between the inside and outside of the box.  In that respect, 
providing the moisture seal changes nothing.  (I assume that by "air 
circulation in the box" you mean the exchange of air between the inside 
and outside of the box.  Quasi-hermetically sealing an already tight 
shielded box would not change the air circulation *inside* the box.)

Further, a relatively close-fitting sealed box tends to minimize 
convection currents inside the box and to create an isothermal 
environment, avoiding the effects of drafts and circulation patterns 
that often plague sensitive circuits sharing a larger volume with other 
circuitry.

So, yes, as always, you have to think about heat flow, but 
quasi-hermetically sealing an already tight shielded box poses no 
additional complications.  In fact, using a close-fitting sealed box 
tends to minimize thermal gradients inside the box.

Charles