Re: [neonixie-l] Re: IN-18 Blue Dream PWB

Thanks for the link on the TI document. I agree that in this particular circumstance it is probably not a latchup condition. In one specific case I came across recently I never dug deep enough to check if it was a proper latchup or not but it certainly looked like it as it pulled the 5V line

Re: [neonixie-l] Re: IN-18 Blue Dream PWB

On second thought, the resistor value I stated is still too low because the worst-case scenario is when the 3.3V supply is off (zero volts), and the 5V supply is fully on. That would make the minimum resistance around 175 ohms = (5.0 - 0.7)/25mA . -- You received this message because you are

Re: [neonixie-l] Re: IN-18 Blue Dream PWB

I'm doubtful that latch-up is happening here, because it usually results in a short-circuit across the supply. Also, the problem as described happens after a few hours of operation, and not during power-up. I'm suspecting a hold-time marginality.

Re: [neonixie-l] Re: IN-18 Blue Dream PWB

I don't know anything about this clock in particular but I have come across several other designs where a mix of TTL ic's, CMOS ic's and other ic's with different VCC capabilities has been used, some starting to operate from as low as 1.8V and some like TTL above 4.75V, but all capable of

Re: [neonixie-l] Re: IN-18 Blue Dream PWB

Those ICs should last forever, because they are not exposed to anything hazardous (high-voltage, high-temp, high current). My hunch is that there is a design marginality somewhere, and that as the part itself ages, or it's surrounding parts, the marginality becomes a defect. -- You received

Re: [neonixie-l] Re: IN-18 Blue Dream PWB

I also replaced one of those on a friends blue dream clock for exactly the same issue. Nick Sent from my iPhone > On Dec 27, 2017, at 11:29, MichaelB wrote: > > Sounds like the same exact issue I had. Replaced 2 of the 74HC595D's. Problem > vanished > >> On

[neonixie-l] Re: IN-18 Blue Dream PWB

Sounds like the same exact issue I had. Replaced 2 of the 74HC595D's. Problem vanished On Wednesday, December 27, 2017 at 11:17:45 AM UTC-8, dixter wrote: > > working with Dieter on the issue now... > > Note: Blue Dream Nixie Clock > > Symptom is flickering of the two hour nixie tubes. for

[neonixie-l] Re: IN-18 Blue Dream PWB

working with Dieter on the issue now... Note: Blue Dream Nixie Clock Symptom is flickering of the two hour nixie tubes. for example when a 0 is displayed you also see a 1 flicker on at the same time for both nixie tubes in the hour slots... schematic reference is Valve 1 and Valve 2

[neonixie-l] Re: IN-18 Blue Dream PWB

When you find the cause of the failure, please share. It helps us design better clocks. -- 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

[neonixie-l] Re: IN-18 Blue Dream PWB

Yep, I recently had an issue with that clock and it ended up being a shift register. Easy fix. Ping Dieter and tell him what the issue is. He may be able to advise you on a fix. On Tuesday, December 26, 2017 at 4:17:39 PM UTC-8, Greg P wrote: > > Thanks for the clarification. That's a new one

[neonixie-l] Re: IN-18 Blue Dream PWB

Thanks for the clarification. That's a new one on me, never heard that term. What exactly is the issue with your clock? I'm sure the folks here can help troubleshoot the issue or failing components. Might not be necessary to source a new PCB. Have you reached out to the Nocrotec/Dieter for

[neonixie-l] Re: IN-18 Blue Dream PWB

PWB = Printed wire board or PCB= Printed circuit board On Tuesday, December 26, 2017 at 11:37:50 AM UTC-6, Greg P wrote: > > What is a PWB kit? > > > > On Tuesday, December 26, 2017 at 10:35:46 AM UTC-5, dixter wrote: >> >> Any one have a source for a PWB for the IN-18 Blue Dream

[neonixie-l] Re: IN-18 Blue Dream PWB

What is a PWB kit? On Tuesday, December 26, 2017 at 10:35:46 AM UTC-5, dixter wrote: > > Any one have a source for a PWB for the IN-18 Blue Dream Clock mine > is acting up and I am wondering how long it will last so I am going to > try and purchase a new PWB kit to fix it > >