A scope will tell you a lot. I suspect the power supply is generating spikes and your meter is picking them up at different times, giving the impression of random voltages.
On Thursday, September 4, 2025 at 6:14:49 PM UTC-7 JBro63 wrote: > I don't have anything that big lying around unfortunately. Would an > oscilloscope be a better instrument? I have a very old Tektronix I can try. > > I'm reading <https://nick.desmith.net/Electronics/NixiePSU.html> board > layout is very important for these types of supply; currently this test > piece is all soldered together adhoc with bits of wire so I think I'll > built order a test PCB in the meantime. > > Thanks. > On Thursday, 4 September 2025 at 15:45:11 UTC+1 Nick Andrews wrote: > >> You may need a higher impedance meter to measure high voltages, >> especially low current supplies as the typical meters will pull >> the measured voltage down. If you use a 1 GOhm resistor to make a voltage >> divider, it's much easier to measure high voltages more accurately on >> these tiny supplies. >> >> On Thu, Sep 4, 2025 at 2:34 AM 'JBro63' via neonixie-l < >> [email protected]> wrote: >> >>> Hi all. >>> >>> I'm looking to incorporate a 12v -> HV power supply in to a PCB design >>> rather then use the excellent external 6300/8200 Omnixie's. As a starter, >>> have sourced the components for the threeneurons NK02. The only change was >>> replacing R5/RX with a single 9.1k resistor. >>> >>> Once assembled (all components soldered) it seems to work ok - lights up >>> a neon or nixie as expected. I'm unable to get a reliable reading of the >>> output voltage using a multimeter, the values are all over the place >>> sometimes exceeding the 600v max of the meter which concerns me a little. >>> >>> Anyone have any tips or insights on this behaviour? >>> >>> The NK02 design is from this >>> <https://threeneurons.wordpress.com/nixie-power-supply/hv-supply-kit/> >>> page. >>> >>> Thanks. >>> >>> -- >>> 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, visit >>> https://groups.google.com/d/msgid/neonixie-l/e0176390-9db5-4a88-bf6b-5d25043707c6n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/e0176390-9db5-4a88-bf6b-5d25043707c6n%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, visit https://groups.google.com/d/msgid/neonixie-l/4add80b7-7688-4837-8aee-be49956876f2n%40googlegroups.com.
