Sure thing. Assuming that your circuit is 1:1 schematically and component wise, the biggest remaining variable would be your physical layout.
Switched mode power supply performance is very layout critical, as you often have both high current and high frequency signals on power circuits, in addition to sensitive feedback circuits which supply the switching controller's logic. The layout can very well make or break the circuit, so it is important to see both where your components are placed, as well as the copper that connects them together and to the rest of your circuit. I went though all of this personally when I first began designing nixie power supplies. You can see some of the thought process put into words on my first power supply related posts here: https://neonkev.com/2019/08/18/project-20-watt-high-voltage-boost-converter/ Some good reading about switched mode power supply layout considerations and best practices: https://techweb.rohm.com/knowledge/dcdc/dcdc_pwm/dcdc_pwm03/2734 Let's start with seeing the layout of your design and the physical test setup. A picture is worth a thousand words. On Mon, Aug 31, 2020, 10:11 AM Max DN <flataeg...@gmail.com> wrote: > Thanks Kevin. You are absolutely right. I'm actually thinking that you > guys are so far ahead with these projects that it's not a good use of your > time. Anyway, since you are familiar with this type of work, hopefully it's > obvious what I am doing wrong if anyone is willing to help without spending > too much time on it. Or I'm thinking it's simply that the cables for the > prototype are just too long at 20-30 mins each or the QS27 Nixie I'm using > to test. > > Anyway, I've attached a picture to show the cabling, doesn't add much to > what you may need. But other then that the actual prototype, everything is > 100% as per this schematic in the link below. Checked probably over 10 > times before ordering the PCBs and checked 3 times over after assembling > the components. http://www.cathodecorner.com/nwl/NWLD5schem.pdf > I even managed to source the flyback transformer 31105, which seemed > difficult to find these days. So, everything is 100% as per that schematic, > list of components etc. > > Il giorno lunedì 31 agosto 2020 alle 14:52:32 UTC+1 Kevin A. ha scritto: > >> In order to assess what is happening with your circuit, we need more >> information. Schematic, bill of materials, and pictures of your pcb artwork >> (showing copper and component placement) and the actual test prototype. All >> of that information is critical if you want a serious response about >> potential problems and how to move forward. >> >> On Mon, Aug 31, 2020, 6:55 AM Massimo Di Noi <flata...@gmail.com> wrote: >> >>> Hi all, >>> >>> I'm been following this group for a while and finally decided to go back >>> to a hoppy that I had 15-20yrs ago or so, to brush up my old knowledge and >>> to build my personal nixie watch starting from what David at Cathode Corner >>> kindly shared, but looking to improve its efficiency with new chips and to >>> add functionalities similarly to Kopriso watch or else. I like the >>> capacitive buttons etc. >>> >>> This is all very steep for me. I have however managed to learn to use a >>> CAD software to design the PCBs (still haven't worked out to properly >>> solder an ADXL335 by hand, I find that challenging even with a microscope >>> but what I have done so far seems fine for a prototype project. >>> >> >>> I have put it all together and it works! Almost: only issue I have is >>> the voltage clamping, which I don't understand well. >>> >>> I couldn't find B5870 Nixies, so for now while testing I'm using chip >>> Q27 Nixies. >>> >>> I do get a stable 158V from the power supply. I believe I need 180V as >>> per descriptions on Cathode Corner's webpage. Looking at the resistor >>> divider, I should be getting 163V, so the HV circuit seems to work, I >>> think. Not sure why David says it should give 180V. So I may be doing >>> something wrong or the values of the resistor divider on the schematics are >>> incorrect (I very much doubt so!). I calculated >>> 1.22V*[1+(510k+510k)/(7.5k+150)]=163.8V as per datasheet of the LT 1308B. >>> >>> Thing is, the whole things works, keeps the time etc but if I connect >>> the VCLAMP (to clamp the 083A darlingtons to 51V - see link to schematic >>> below), then nothing happens, only one of the Nixies goes on, but it's very >>> fainted. >>> >> >>> What am I missing? >>> >>> This is what I am looking at: >>> http://www.cathodecorner.com/nixiewatch/theory/theory.html >>> http://www.cathodecorner.com/nwl/NWLD5schem.pdf >>> >>> Obviously I could experiment with different values of the resistor >>> divider but I don't understand why I should do that as I'm sure Dave's >>> design is proven by many years and many watches he sold. So, I'm guessing >>> I'm doing something wrong here. Or it's as simple as the Q27 tube needs a >>> higher maintaining voltage than the B570? I cannot find a datasheet for the >>> Q27. But then again, why Dave talks of 180V out of his HVPS? I'm going in a >>> loop... >>> >>> Any help would be much appreciated. >>> >>> Thanks, >>> Max >>> >>> >>> -- >>> 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+...@googlegroups.com. >>> To view this discussion on the web, visit >>> https://groups.google.com/d/msgid/neonixie-l/d0451e2f-a7ec-470a-a268-eecedd2ffc3en%40googlegroups.com >>> <https://groups.google.com/d/msgid/neonixie-l/d0451e2f-a7ec-470a-a268-eecedd2ffc3en%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 neonixie-l+unsubscr...@googlegroups.com. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/1474844f-bc92-41e6-80ce-f242a09179f6n%40googlegroups.com > <https://groups.google.com/d/msgid/neonixie-l/1474844f-bc92-41e6-80ce-f242a09179f6n%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 neonixie-l+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CALcVLKKc3wqPxWaPRXK0oqOKFegvLxLdQY7X4NzzALmDAEGDYw%40mail.gmail.com.
