My Nixie watches have a variable 5-30pF capacitor on the crystal so that I can adjust the oscillator to exactly 32768 Hz. You could use a different value depending on your crystal characteristics. I use an old Hewlett Packard universal frequency counter, running in time period averaging mode, measuring the time period of 10,000 cycles of the oscillator. I connect an oscilloscope probe to the oscillator output pin on the PIC computer to achieve minimum loading of the crystal circuit. I have to adjust it to run a bit slow with the probe connected, to get proper timekeeping when the probe is removed. I can adjust it to within one second per week using this technique. I've done this on 2000 Nixie watches by now, so it works.
On Mon, Apr 19, 2021, 1:23 AM MrThe50sanchez <[email protected]> wrote: > Hello Guys! > > I have a nice question to ask you guys if you can give me some help. > > I builded a Nixie watch, It works good, but I'm having a little bit of > time delay, 1* min within 6 hours. * > > At the *first time,* I had 6 min delay for 6 hours aproximately. I > investigated the relation of the cristal and the capacitors you need to > install with it. First, I had 22pF for a cristal that requires 12.5pF, > giving me that 6 min delay for 6 hours, then, I realised these and > installed 10Pf capacitor and the delay decreased to 1 minute for 6 hours, > and I just ordered new capacitors of 12pF to get more closer to the > manufacture requires, So I imagine that the delay is gonna get less. > > ·Is there any way to make this time delay shorter? > ·Do you recommend me a tipe of cristal that is really acurate to install > on my watch? > > Thanks a lot nixie lover's > > -- > 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 view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/7ce2b557-f652-44b2-a71f-ed75b96ea06fn%40googlegroups.com > <https://groups.google.com/d/msgid/neonixie-l/7ce2b557-f652-44b2-a71f-ed75b96ea06fn%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CAPbqtvfXMhwT4BZLp64Rn_1SpMxDa-46RBVcpLMgkb0-4fFxMw%40mail.gmail.com.
