[volt-nuts] LTZ1000 project build

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 4 Jun 2016 20:44, "Poul-Henning Kamp" <phk at phk.freebsd.dk> wrote:
>
> --------
> In message <57527F8A.6070108 at yandex.com>, Charles Steinmetz writes:
>
> >As I have mentioned before, for many years I have put precision circuits
> >that may be sensitive to humidity into gasketed metal boxes with fresh
> >silica gel packets.

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

I don't know how practical they are, but I have see humidity calibration
standards (e.g 50%). These  use a chemical reaction to keep a volume at a
constant humidity.  That might be a way of keeping the humidity constant,
without introducing increasing thermal gradients.

They might introduce a whole host of other problems,  so such a method
would need researching.

If a new PCB was designed,  it would be nice if there were pads to take the
expensive Vishay foil resistors,  in addition to a cheaper choice.

Dave