[time-nuts] Digital clock competition
Didier Juges
didier at cox.net
Thu Nov 29 21:29:29 EST 2007
Personally, I think the choice of LED display for such a project is a poor
one. You can get LCD displays for less than $15 if you look a little bit,
and the power consumption will be much lower, which will make a number of
other things easier and the end product more desirable, such as being able
to run on batteries, which would be well aligned with modern trends. For
such a project, it seems that a TCXO approach makes more sense than an OCXO.
The XO and its temperature compensation could be precalibrated against a
known good reference, and the end product would be stable and have low power
consumption. A simple microcontroller would divide the crystal, drive the
LCD, and do the temperature compensation.
When is the due date for the project submissions?
Didier KO4BB
> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Murray Greenman
> Sent: Thursday, November 29, 2007 4:58 PM
> To: p.ross at ieee.org
> Cc: time-nuts at febo.com
> Subject: [time-nuts] Digital clock competition
>
> Philip,
>
> I am interested in your design challenge for an accurate
> digital clock, but although I've searched the IEEE Spectrum
> on-line magazine, I can find no mention of it. All I have is
> an email from you circulated through the TimeNuts group.
>
> It will be important to know the ground rules for the
> project. For example, what is the expected operating
> environment? What is the power budget? Need the display be
> 7-segment, and is any other technology permitted? Where, when
> and how is the calibration to be performed, and over what
> time period will accuracy be checked, and by what method?
>
> Most especially, we need to know what the definition of parts
> being 'generally available' means, and we need to know who
> decides how the cost of construction is defined. I published
> a $30 design using recycled parts capable of 10sec/year some
> two years ago - how would I know if it would it be eligible?
>
> Please send me detailed information, or tell me where I may
> find it. If it's not been clearly defined then the
> competition will not generate any serious interest.
>
> Regards,
>
> Murray Greenman
> Senior Engineer,
> Oscillator Engineering,
> RAKON
>
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