Good point. Standard practice with logic ICs is to distribute 0.01 to 0.1uf ceramic caps uniformly around the board, from power to ground. I like to use one cap per IC. That's why I recommend people should get an old copy of the TTL Cookbook (from Don Lancaster). CMOS Cookbook is also good. 4000 CMOS, as used on the Harrison clock should be more immune to noise than 7400 TTL. So If you use the TTL precautions on CMOS, it should give you extra insurance.
Also, make sure the AC, used as the timebase is clean. This circuit uses high value resistor, and lets the 4013's static protection, clamp the voltage. There's also a small capacitor to filter the line noise. On Sunday, March 16, 2014 4:32:41 PM UTC-7, Michail wrote: > > I have about 10 of the clocks. > > Various issues with them. > Mostly the issue was with a 4017 (certain type) > It would count to the 10th hour and reset instead of going to 11, 12 > > Sounds like you might have some line noise. I believe the original > circuit was changed to add some caps. Do you have the circuit you used? > > > Michail Wilson > 206-920-6312 > > In a message dated 3/16/2014 1:39:24 P.M. Pacific Daylight Time, > [email protected] <javascript:> writes: > > Hi all, > What could make one of the Mike Harrison Nixie clocks run erratically? > It's basically running fast, but it also does this erratically- sometimes > it looks like the seconds are counting at the proper speed, but then they > will speed up...? > I'm using the pre-made board with an added seconds driver board, and it's > a new build; just testing it at this time. > Thanks for any ideas, > -Brian > > -- 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/1de9c28d-c8dc-4d4b-b054-fe3196c6c613%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
