Drat!  D2 polarity is reversed on the schematic, should be pointing toward
the + rail.  It doesn't conduct until the + line is grounded; then the cap
discharges through it.

Yrs,
d

On Sun, Aug 6, 2017 at 10:11 PM, David Beierl <dbeierl@attglobal.net> wrote:

> It's the combination of the cap size and R2 size.
>
> Increasing R2 value at some point will run into the cap's internal leakage
> (just like the temp gauge blinker timeout circuit) and fail to time out
> and/or become excessively sensitive to humidity and board contamination.
>
> Yrs,
> d
>
> On Sun, Aug 6, 2017 at 10:03 PM, Alistair Bell <albell@shaw.ca> wrote:
>
>> Ok, I'm not going to pretend to know... is it just the cap that
>> determines delay time?
>>
>> Ab
>>
>>