The way the pulse-remover works is at the end of each hour it gets triggered, which shuts off the 32.768 kHz pulses from getting to the first divider stage of the clock.
A binary counter then counts out the "removed" pulses which are entered on an 8-bit dip switch. At the end of the counting, a flip-flop is clocked which returns the pulse stream to normal. So far in my experiments with this "remover" which I have on 4 clocks here, it averages out to around 110 to 115 pulses which need to be removed each hour. Each individual TCXO is a bit different. If I ever encounter a slow TCXO, I've got some ideas for making a "pulse-stuffer" instead. Chuck > > >---- Original Message ---- >From: [email protected] >To: [email protected] >Subject: Re: [neonixie-l] Erratic Harrison clock >Date: Mon, 17 Mar 2014 08:58:21 -0700 (PDT) > >>On Monday, 17 March 2014 15:46:33 UTC, Chuck wrote: >>... >> >>> For much greater accuracy, I've devised a programmable >>> "pulse-remover" which shaves off a predetermined amount >>> of pulses each hour. This, because every one of those >>> TCXOs I've encountered tends to run a bit fast. >>> >> >>Essentially this is a digital low-pass filter - Ronald Dekker does >the same >>on his nixie clocks some of which use almost the same way of getting >the >>mains frequency - you can also determine the fundamental, i.e. is >the clock >>running on 50 or 60Hz mains, and adjust accordingly... >> >>Nick >> >>-- >>You received this message because you are subscribed to the Google >Groups "neonixie-l" group. >>To unsubscribe from this group and stop receiving emails from it, >send an email to [email protected]. >>To post to this group, send an email to [email protected]. >>To view this discussion on the web, visit >https://groups.google.com/d/msgid/neonixie-l/4e403071-a508-4b88-841c- >ac7bfca8bdea%40googlegroups.com. >>For more options, visit https://groups.google.com/d/optout. >> $4.95/mo. National Dialup, Anti-Spam, Anti-Virus, 5mb personal web space. 5x faster dialup for only $9.95/mo. No contracts, No fees, No Kidding! See http://www.All2Easy.net for more details! -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/380-22014311716738426%40all2easy.net. For more options, visit https://groups.google.com/d/optout.
