Brooke: You have been thinking about this longer than I have. I presume you have not tried to make any prototypes? Ronald Message: 1 Date: Fri, 28 Dec 2007 15:19:49 -0800 From: Brooke Clarke <brooke@pacific.net> Subject: Re: [time-nuts] accurate portable time source To: Discussion of precise time and frequency measurement <> Message-ID: <47758495.7070707@pacific.net> Content-Type: text/plain; charset=us-ascii; format=flowed Hi Ronald: Here are a some of ideas for the heart beat for a LCD based clock like the ones I've been developing. Best) A Vectron EX-380 series Vacuum OCXO only draws 0.35 Watts and if the 5 volt version that's only 70 ma. So a single AA would have enough energy, three AAA Ni-MH would be great. That was the good news. The bad news is that they are made of unobtanium (i.e. very expensive or need to be bought in large lots). Good) An alternative is the DS3231. This is an advanced version of the DS32khz TCXO and is adjustable to 0.1 ppm using the digital serial interface. Provision for a coin cell back up battery. unknown) One of the DS3231 parts, in a thermal enclosure that has a time constant in excess of 24 hours. I think it's about the size you request. A temperature sensor changes the divisor based on calibration data. Sort of a doubly compensated device TTCXO or T2XO. I like this one for a practical product. Have Fun, Brooke Clarke http://www.PRC68.com http://www.precisionclock.com http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Cam

Hi Ronald: The last LCD clock I made had the pads for a DS3231 but for various reasons I never installed it. http://www.prc68.com/I/PRC68COM.shtml#07092006 Have Fun, Brooke Clarke http://www.PRC68.com http://www.precisionclock.com http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Cam Ronald Held wrote: > Brooke: > You have been thinking about this longer than I have. I presume you > have not tried to make any prototypes? > Ronald > > Message: 1 > Date: Fri, 28 Dec 2007 15:19:49 -0800 > From: Brooke Clarke <brooke@pacific.net> > Subject: Re: [time-nuts] accurate portable time source > To: Discussion of precise time and frequency measurement > <> > Message-ID: <47758495.7070707@pacific.net> > Content-Type: text/plain; charset=us-ascii; format=flowed > > Hi Ronald: > > Here are a some of ideas for the heart beat for a LCD based clock like the ones > I've been developing. > > Best) A Vectron EX-380 series Vacuum OCXO only draws 0.35 Watts and if the 5 > volt version that's only 70 ma. So a single AA would have enough energy, three > AAA Ni-MH would be great. That was the good news. The bad news is that they > are made of unobtanium (i.e. very expensive or need to be bought in large lots). > > Good) An alternative is the DS3231. This is an advanced version of the DS32khz > TCXO and is adjustable to 0.1 ppm using the digital serial interface. > Provision for a coin cell back up battery. > > unknown) One of the DS3231 parts, in a thermal enclosure that has a time > constant in excess of 24 hours. I think it's about the size you request. A > temperature sensor changes the divisor based on calibration data. Sort of a > doubly compensated device TTCXO or T2XO. I like this one for a > practical product. > > Have Fun, > > Brooke Clarke > http://www.PRC68.com > http://www.precisionclock.com > http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Cam > > _______________________________________________ > 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. >