Without knowing your exact design I cannot recommend a specific xtal. For instance, PIC processors recommend a xtal with a load capacity of about 12pF, while other designs are optimized for different xtals. Often the devise data sheet will give you a short list of recommended xtals which have been tested by the chip designer. The main thing is that for critical applications (such as a time keeping devise) always get a good brand name item with full specifications. Often xtals used for running a program are not critical, so there you can sometimes get away with something cheap; as long as it runs, and is close. I am a great proponent of recycling, but saving 32kHz clock xtals is not worth the trouble. Xtals are complicated; there are different cuts and styles, all specific to particular applications.
There is a great app note from Microchip worth reading: http://ww1.microchip.com/downloads/en/appnotes/00949a.pdf Even Wikipedia has a decent chapter on xtals: https://en.wikipedia.org/wiki/Crystal_oscillator Lots of other good information sources on the interweb. Cheers, Bill From: [email protected] [mailto:[email protected]] On Behalf Of MrThe50sanchez Sent: Tuesday, April 20, 2021 12:22 PM To: neonixie-l <[email protected]> Subject: Re: [neonixie-l] CRISTAL + CAPACITOR = TIME DELAY HELP Hello Bill, Thanks a lot for your answer and your knoledge, I will do a chart with different capacitors values and I will see how the time delay get's. I'm using two capacitor to ich leg of the cristal. as you say, my cristal is not that good, do you recommend a cristal in specific? thanks a lot! El lunes, 19 de abril de 2021 a las 14:34:49 UTC+2, Bill van Dijk escribió: If you are still slow with the 10pF, a 12pF is not going to do it. The relationship between the crystal and load capacitor is critical, and it is therefore a mystery to me that so many (of the cheaper) are sold without the specifications. Anyway, if yours is a cheap Chinese crystal, try some other ones, perhaps you just got a bad one. Generally I always like to get a good brand name crystal. If you want to play with the one you have, try something lower yet, 8 or 7pF. In general terms, and within limits, larger cap slows it down, smaller cap speeds it up. Sometimes (if you use 2 caps) using a slightly different cap on one leg of the crystal can make a difference in the final frequency. Bill From: [email protected] <mailto:[email protected]> [mailto:[email protected]] On Behalf Of MrThe50sanchez Sent: Monday, April 19, 2021 4:23 AM To: neonixie-l <[email protected] <mailto:[email protected]> > Subject: [neonixie-l] CRISTAL + CAPACITOR = TIME DELAY HELP 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] <mailto:[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] <mailto:[email protected]> . To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/5e51943e-d45c-4421-b00c-06fb2dc8380fn%40googlegroups.com <https://groups.google.com/d/msgid/neonixie-l/5e51943e-d45c-4421-b00c-06fb2dc8380fn%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/013901d7360c%2491079660%24b316c320%24%40gmail.com.
