PI controllers can be implemented analog only. For the PPS they need large capacitors that are the equivalent of averaging (sum and accumulate) in a software implemented controller.
On Sat, Dec 31, 2011 at 7:54 AM, Chris Albertson <[email protected]>wrote: > On Fri, Dec 30, 2011 at 11:46 AM, Stanley <[email protected]> wrote: > > > > > >> > >>> "What is the simplest design for a GPSDO that uses only the PPS signal > >>> from > >>> a modern GPS?" > >> > >> > >> Some sort of oscillator with a voltage control. > >> CPU with a timer/counter that can capture the PPS. > >> DAC. > >> Software. > >> > > > > How about MSC1200 : http://www.ti.com/lit/ds/symlink/msc1200y3.pdf > > I don't count anything with a computer and software inside as > "simple". My definition of a simple device is a capacitor or a > transistor or I guess a single flip-flop or op-amp. A simple > controller would some how use about two dozen or less of these kinds > of components. > > Home heating thermostats can be simple of complex. Some use LCD > displays and a computer. Other have a simple bimetallic spring > inside. > > If this CAN'T be done. And if a computer is really required. I'm > going to go all out and use a "real" computer. Something that can run > an operating system and talk on the network. Here is an example of > what I mean > > http://www.embeddedarm.com/products/board-detail.php?tab=options&product=TS-7550# > > No one really wants a device that connects to a computer over a serial > port. That was 20 years ago. The above board can host a web site > and log data to a USB thumb drive and burns less then 2W of power > > But for now I'm looking for a controller that is much more like the > bimetallic spring thermostat. > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
