marți, 20 mai 2014, 15:43:16 UTC+3, Cristinello a scris: > > Hello guys, > I built a relatively simple nixie clock and I am encountering severe > ghosting issues. To drive the mainboard I used an Arduino ( because I lack > programming knowledge) . I will attach the schematic and the .ino file from > the Arduino IDK . The schematic does not contain the nixie board beacuse it > is a modular design but it is straightforward. I am using 4028 BCD to > decimal decoder to drive the nixies and the transistors are SMD versions of > the FMMTA92 and 42. The power supply has also a strange behaviour , when > left without any consumer , the output voltage is going down wih aprox > 1Volt/30 seconds. If someone has any idea about what may be wrong I will be > very very grateful .Thank you in advance! >
Hello , I abandoned my design for a few months but last week I retried fixing the ghosting issues. I used an oscilloscope to try and identify the problems and I observed the following : -> Due to the fact that my nixies are soldered on a separate board , the connections being only the anodes and cathodes , I observed that the wires connecting the boards are capacitively coupled and I could observe command impulses from one anode to the next ( lower amplitude of course ) . I fixed this adding one capactior in paralel with a resistor from each of the anode wires to GND ( on mainboard). -> After fixing the clock timings , there was still ghosting on the tubes which I was not able to fix from software. A colleague of mine came up with the solution to add on each cathode an diode ( I added 1N4148 , 60 of them :) ) and the ghosting dissapeared . The problem with my design is that on the nixie board all the cathodes are tied together and the ghosting occurs like this : if I select tube A ( anode to VCC ) and pull the furthest cathode (from the anode ) to GND , all the cathodes inbetween will have a proportional charge , which in the tubes B , C ,D ,E ,F translates as discharges between cathodes , aka ghosting. I posted my findings so that it may help others in dealing with these issues . Good day! -- 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/09d57b55-e75d-4d79-8484-b22da79d7d3b%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
