[time-nuts] Car Clock drift - the lowly 32kHz tuning fork crystal specs
kb8tq at n1k.org
Mon Apr 10 07:03:09 EDT 2017
> On Apr 9, 2017, at 10:01 PM, Alex Pummer <alex at pcscons.com> wrote:
> actually it does not compensate for temperature it is just for reduce the production cost for the crystal. We --Jean Hoerni [founder of intersil, Eurosil and one of the traitors who started Fairchild Semiconductor] and me -- made something very similar at the time of begin of the quartz clock era for Lipp a French watch maker in Bezancon [a city an France the spelling is most likely not correct]. The company exhibited it at the Basler exhibition of Horology, the clock was simple good working and not to expensive, Ebachos --OMEGA -- people visited the booth, they also had their quartz clock which was much more expensive -- they looked, the Lipp clock and told na there are Rolls-Royce s and deux chevaux [that was a simple little ugly but very reliably French car ] as response Mr. Hoerni told them yes, and there are technologies not known in your house, the Omega people recognized him and walked away quietly...
Just to put this in context. The “prior state of the art” was to have a trimmer capacitor in the watch (or clock) module to set it on
frequency. That’s why it was obvious from a quick look that something was different. There were semiconductor companies making
watch modules at the same time still using trimmer capacitors. The pulse drop / add was not at all an “obvious” solution at the time.
> On 4/9/2017 1:11 PM, Bill Hawkins wrote:
>> Nice article in Wikipedia. Didn't see any familiar names in the
>> reference list, though.
>> Seems to me inhibition compensation is useful for compensating for the
>> variation in purchased crystal frequencies, but not for temperature
>> Also seems to me that a watch spends 2/3 of a day at wrist temperature
>> and 1/3 at bedroom temperature, which varies with the seasons.
>> Would a ceramic capacitor crafted for a certain temperature coefficient
>> work? Can the fork have a crafted tempco?
>> Bill Hawkins
>> -----Original Message-----
>> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Ron
>> Sent: Sunday, April 09, 2017 12:05 PM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] Car Clock drift - the lowly 32kHz tuning fork
>> crystal specs
>>> In your case, the car sits in an environment that matches their test
>>> setup well. In my case ?\200? not so much.
>> FWIW, mine drifts pretty badly. It's in an aftermarket stereo, and I
>> don't remember when I bought it (I moved it from my previous car).
>> I assume that all quartz clocks and watches these days use "inhibition
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