[time-nuts] quartz clock/watch question

[Bob Albert]

I have tried to pick up the oscillator from my wristwatch and have been unsuccessful.


I tried both magnetic and electric probes.  Nothing.

Bob

On Friday, April 18, 2014 4:12 PM, Tom Van Baak <tvb at LeapSecond.com> wrote:
 
> When a quartz watch or clock is assembled, what method is used to get it as accurate as possible?

Bob,

First generation quartz watches had a tiny F/S (fast/slow) trimmer capacitor. These days it's done with skip cycles and one-time factory calibration. Think leap days or leap seconds -- it's easier and more reliable than changing the frequency of the oscillator itself. It's also one less part, easier to calibrate, and unlike active and passive components, math has no environmental sensitivity.

Have a quick read of 32 kHz watch IC's like:
http://www.nxp.com/documents/data_sheet/PCA2000_2001.pdf

/tvb


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