Could someone explain what the reforming involves ? Thanks Ian
> On 20 May 2022, at 06:12, SWISSNIXIE - Jonathan F. <[email protected]> > wrote: > > I've used a MAX1771 with ceramic capacitors a while ago for a > pandicon-circuit and a smaller nixie project. Both consume less than > 15mA@170V. Not sure how the circuit would behave at more current. > >> On Thursday, 19 May 2022 at 20:03:18 UTC+2 Dekatron42 wrote: >> A few other things that I experienced at my previous employer was that >> larger (sizewise) MLCC capacitors easily developed cracks, came loose from >> the circuit board and also needed reforming after storage. >> >> /Martin >> >>> On Thursday, 19 May 2022 at 05:01:25 UTC+2 [email protected] wrote: >>> Roger, >>> >>> Yes. Looks like the common dielectrics (X7T, X7R) available in the 250v >>> 1-3uf range suffer from a 30-80% reduction in capacitance at 180v. I hadn't >>> realized it was that high. >>> Thank you, I'll look at the polymer caps. It's my last remaining >>> electrolytic on my board and if possible I would like to use a solid one >>> instead. >>> >>> Regards, >>> -Moses >>> >>>> On Wednesday, May 18, 2022 at 7:54:10 PM UTC-7 Roger Brinkman wrote: >>>> Hi Moses, >>>> >>>> What David writes below about the capacitance reduction of ceramic >>>> capacitors is correct. >>>> I have experienced success using polymer aluminium electrolytics (solid >>>> electrolyte) to replace conventional low-ESR electrolytic capacitors that >>>> regularly fail in similar applications. >>>> You might like to experiment with these. >>>> >>>> Best regards >>>> Roger Brinkman. >>>> >>>>>> On 19 May 2022, at 12:42 pm, David Forbes <[email protected]> wrote: >>>>>> >>>>> >>>> >>>>> I haven't tried it, but I can make some observations. The MAX1771 isn't >>>>> connected directly to the output circuit, so it's not likely to suffer >>>>> from a problem. The current flows through the inductor which will >>>>> accommodate a momentary short circuit caused by the capacitor. >>>>> In short, it shouldn't be a problem. >>>>> Bear in mind that the effective capacitance of a modern ceramic capacitor >>>>> is much lower with a DC bias near its rated voltage, so you would need to >>>>> use either capacitors rated for 5x the output voltage, or about 5x the >>>>> desired capacitance. >>>>> Some capacitor data sheets publish this reduction in capacitance as a >>>>> function of bias voltage, most don't. Look for it. >>>>> >>>>> >>>>>> On Wed, May 18, 2022, 6:49 PM Moses <[email protected]> wrote: >>>>>> Before I let the magic smoke out of half a dozen MAX1771 ICs.. has >>>>>> anyone ever tried using ceramic output capacitors? It wants a low ESR >>>>>> capacitor, so ceramics may work well. >>>>>> >>>>>> The datasheet doesn't mention ceramics on the output side.. but then >>>>>> again it was written a few decades ago when the required >>>>>> voltage/capacitance probably was not readily available. >>>>>> >>>>>> Regards, >>>>>> -Moses >>>>>> -- >>>>>> 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 on the web, visit >>>>>> https://groups.google.com/d/msgid/neonixie-l/7ae38dca-64ca-459d-a1e5-283a062f8f9en%40googlegroups.com. >>>>> >>>>> -- >>>>> 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 on the web, visit >>>>> https://groups.google.com/d/msgid/neonixie-l/CAPbqtvcg0ak%2BLMH_7JJ01eFnYjFzu38v2N59k8ZfoFxrRY3J_g%40mail.gmail.com. > > -- > 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 on the web, visit > https://groups.google.com/d/msgid/neonixie-l/bb141fcc-15ab-45de-a7ae-c9b38a3710dbn%40googlegroups.com. -- 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 on the web, visit https://groups.google.com/d/msgid/neonixie-l/22F362C4-0CFA-4825-BA2B-19C74B047A41%40yahoo.co.uk.
