[time-nuts] Generating a solid PPS from 10Mhz source
artgodwin at gmail.com
Mon Jan 18 17:05:17 UTC 2016
You might have come across the Raspberry Pi story : one of the revised
versions had a SMPS control chip that was intended to be buried inside a
phone, not exposed on an open pcb.
On Mon, Jan 18, 2016 at 3:11 PM, Bob Camp <kb8tq at n1k.org> wrote:
> Back in the 70’s I was involved in making LCD watches. The whole “photo”
> issue had not been fully through through. One day our chief marketing guy
> the project was driving around in Phoenix AZ. He looks down and notices
> his watch is dead. Pops out a spare, puts it on, confirms it it working.
> Hangs his arm out
> the window and …. that one is dead as well.
> We changed the die coat on the ASIC to an opaque version soon after that …
> Light does indeed interact with semiconductors. It happens even on
> circuits that
> you would not *think* are photo sensitive. Physics is nasty that way ….
> > On Jan 18, 2016, at 6:45 AM, Poul-Henning Kamp <phk at phk.freebsd.dk>
> > --------
> > In message <569BC23A.3030400 at arcor.de>, Gerhard Hoffmann writes:
> >> LEDs abused as References:
> > This is one of the most stupid ideas ever, because LEDs works both ways.
> > (Back when LED wrist-watches first came out, people soon discovered
> > that they would reset themselves when photographed with flash.)
> > If you insist on using LEDs as voltage references, the first thing
> > you need to do is to dip the LED in something which shields it 100%
> > from incoming light *including infrared*
> > --
> > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
> > phk at FreeBSD.ORG | TCP/IP since RFC 956
> > FreeBSD committer | BSD since 4.3-tahoe
> > Never attribute to malice what can adequately be explained by
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