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/70f7e525-89c0-41d0-9aab-76219440a9bfn%40googlegroups.com.
