Ron Not sure who it would be but the reason to want to use a 1 pps step is its easy to clock. Though the fact that its 2 phase like you have in the pulse makes it tougher. The tick is the second. On a multi-step clock how do you phase the second hand. Visually but complicated through a slew method. Maybe optically but it gets more complicated. If you have 4 clocks for ham radio it really gets messy. So the 1 PPS keeps things reasonably aligned with little effort. Digital clocks remove all this. But I guess I like the analogs. Regards Paul
On Sat, Jan 5, 2019 at 2:30 PM Ron Bean <[email protected]> wrote: > A recent thread talked about noisy clocks (1 tick per second). Some of > you may have noticed that it's now possible to buy cheap quartz clock > movements that have a continuous-sweep second hand, and don't tick once > per second. For example, klockit.com sells two different brands (Seiko > and Quartex, the latter is owned by the same company that owns klockit). > > AFAIK LaCrosse is the only company making consumer-level quartz clocks > with this feature, and only on certain models. I've found that the > plastic gears do make some noise, especially with a large clock face > that acts as a resonator, and they may be audible in a quiet room. But > IMHO they're less bothersome than 1 tick per second. > > A few years ago I put a 'scope on one of the Quartex movements (pic > attached, same pic at http://www.panix.com/~rbean/clock/clock-01.jpg ) > > Like other quartz clocks, they use a "Lavet" type stepper motor > https://en.wikipedia.org/wiki/Lavet-type_stepping_motor > But the electronic timing and mechanical gearing are different (16 pulses > per second). The amplitude is equal to the battery voltage (I think I used > a lithium primary cell, which is a slightly higher voltage than alkaline). > > Some time ago, someone on this list mentioned that he knew someone who > worked with the controller chips in cheap clocks and watches. If anyone > knows which chip runs these things, I'd love to see a data sheet. They > seem to keep remarkably good time for something that costs so little. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
