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 mo...@neonixie.com 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 <nixie...@gmail.com> 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 <mo...@neonixie.com> 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 neonixie-l+...@googlegroups.com. >>>> To view this discussion on the web, visit >>>> https://groups.google.com/d/msgid/neonixie-l/7ae38dca-64ca-459d-a1e5-283a062f8f9en%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/neonixie-l/7ae38dca-64ca-459d-a1e5-283a062f8f9en%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+...@googlegroups.com. >>> >>> To view this discussion on the web, visit >>> https://groups.google.com/d/msgid/neonixie-l/CAPbqtvcg0ak%2BLMH_7JJ01eFnYjFzu38v2N59k8ZfoFxrRY3J_g%40mail.gmail.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/CAPbqtvcg0ak%2BLMH_7JJ01eFnYjFzu38v2N59k8ZfoFxrRY3J_g%40mail.gmail.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/bb141fcc-15ab-45de-a7ae-c9b38a3710dbn%40googlegroups.com.
