Hi Since it’s a magnetic stepper motor, how about a magnetic (coil) sensor?
Based on past data, anything past 1us is massive overkill. A mag sensor with a ~100 KHz bandwidth should be a do-able sort of thing. A couple dozen turns of wire around a suitable ferrite rod might be enough. Bob > On Apr 7, 2017, at 1:03 PM, Tom Van Baak <t...@leapsecond.com> wrote: > >> Very good catch it is *not* the cme8000 chip. Thats a classic am receiver. >> It is the everset chip. Sorry for mis-leading. > > Hi Paul, > > I can confirm (from talking with the guys backing it) that, yes, it's the > EverSet ES100, in die form (CoB). I believe you and I have both used the > early Xtendwave dev kits with the ES100 as SMT part. It's nice to see the > chip still lives and finally made it to a product! > > > I uploaded more ultrAtomic info and tear-down photos: > > http://leapsecond.com/pages/ultratomic/ > > I encourage those of you who just bought these clocks to do some experiments. > The obvious ones are: > > 1) See how long it takes to acquire the correct time, at all sorts of > different and difficult environments, compared to the traditional WWVB > clocks. Check for off-by-one second, or minute, or hour errors. > > 2) See how accurate they really are. For clocks like this I use a variety of > piezo sensors (feel the tick), acoustic sensors (hear the tick), optical > sensors (see the tick), and mostly electrical sensors. Some of these are > passive (non-destructive) timings and good enough. Others require some level > of disassembly but are more precise. For a stepper motor clock it's easy to > tap onto the coil connections and get a sharp pulse every second or two. Then > use a time interval counter, or picPET, or TICC, or PC-based PPS-capture to > collect readings. Note the signal level is usually low power and below > typical TTL levels, and they do NOT drive 50R! > > > If all goes well, we can soon talk about a time-nuts special where we get > someone to make a timing board or disciplined timing board based on the ES100 > chip. The bad news is that at the same price it would be like a million times > worse than GPS. The good news is that lots of applications need only ms level > timing; there are places where WWVB is receivable and GNSS is not; and then > there's the redundancy and low-power factor. > > /tvb > > ----- Original Message ----- > From: "paul swed" <paulsw...@gmail.com> > To: "Discussion of precise time and frequency measurement" > <time-nuts@febo.com> > Sent: Friday, April 07, 2017 5:08 AM > Subject: Re: [time-nuts] The ultraAtomic clock for home > > > Tom > Very good catch it is *not* the cme8000 chip. Thats a classic am receiver. > It is the everset chip. Sorry for mis-leading. > Regards > Paul > WB8TSL > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
