Hello, It's may be a little out of our direct concerns, but do you know this beautiful digital clepsydra: http://www.marcdatabase.com/~lemur/dm-gitton.html
or its Javascript emulation: http://www.time-flow-clock.de/ 73, Jean-Louis Oneto e-mail: [EMAIL PROTECTED] ----- Original Message ----- From: "Normand Martel" <[EMAIL PROTECTED]> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Friday, August 11, 2006 12:02 AM Subject: Re: [time-nuts] Ugly Frequency Dividers > This morning, i've just remembered another weird > frequency divider i say on a chronorecorder (a device > used to adjust mechanical watches) a few years ago... > > The frequency dividers stages (three or four, i'm not > sure) were unijunction transistor based staircase > generators using the charge pump/reservoir principle > to divide the input frequency by an integer "N" > factor. Interinstignly, the "N" factor was adjustable > using a potentiometer. > > Again here, just as with the ring counter, no glitch > problem here, as with the binary dividers, but the pot > had to be carefully adjusted so it is in the middle of > the correct "N" range, this way, the counter can > resist aging. > > Interinstignly, since it uses the charge > pump/reservoir principle instead of the well hnown > gated monostable, this counter is relativey (within a > reasonable measure) frequency independant. > > Again, just as the all-transistor ring counter, i do > not have the schematic, but i know the owner of the > chronorecorder, and next time i'll see him, i'll ask > for a look inside the device to sketch a schematic. > > BTW, i do not know the jitter response of such a > counter, but i can eassilly imagine that it is very > poor (slow transitions), but since it smells analog, i > like it!! ;-) > > 73 de Normand VE2UM > Montreal, Qc, anada > > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > > _______________________________________________ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
