[time-nuts] Thunderbolt? (re simple gpsdo.) >> capacitors

paul swed paulswedb at gmail.com
Thu Jan 5 23:00:10 UTC 2012


Poul
Thanks have been kind of following this thread and the diagram did not make
a lot of sense.
I figured I missed part of the thread. But this clears it up nicely.
Regards
Paul.
WB8TSL

On Thu, Jan 5, 2012 at 5:49 PM, Poul-Henning Kamp <phk at phk.freebsd.dk>wrote:

> In message <CAL8XPmO76XuTETZC=33_v2YWuJGcw8gCvtTDHyae6E4MFb18=
> g at mail.gmail.com>
> , Azelio Boriani writes:
>
> >I have googled extensively trying to find something about the dual
> >capacitor method of reducing the leakage current... nothing found. Please,
> >can you indicate anything for me to learn more?
>
> It is very simple:
>
> R1 charges C1 to the DC potential and therefore C2 sees
> (almost) no DC voltage, which means (almost) no leakage
> current.  C2 is still a capacitor for any AC or dV component.
>
> I belive I picked this trick up from a datasheet or app-note relating
> to precision voltage references.
>
> Poul-Henning
>
> >> [Some op-amp]  >-+-----R2-----+-->
> >>                  |            |
> >>                  |          ----- C2
> >>                  |          -----
> >>                  |    ____    |
> >>                  +---|____|---+
> >>                        R1     |
> >>                               |
> >>                             -----  C1
> >>                             -----
> >>                               |
> >>                              GND
>
> --
> 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 incompetence.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


More information about the time-nuts mailing list