On Wed, 2 Nov 2016 06:56:46 +0100, you wrote: >Hello David, > >On 01.11.2016 15:50, David wrote: >> avoid Mylar/polyester/PET and high dielectric constant ceramic >> capacitors. > >Do you have some specific recommendations/suggestions what to use? > >Polypropylene? PTFE? Wet Tantalum capacitors (extreme expensive)? > >Thanks, > >Andreas
Wet tantalums might be the best for very long time constants but are useless for settling times below hours to days. Some low leakage aluminum electrolytics are just as good. Charles pretty much covered it but I am not sure that polypropylene is always worse than polystyrene. Some of the other plastic films are pretty good also but polypropylene is the most common high performance option. Teflon is the best but is also expensive and has poor availablity. When I looked into this a couple months ago in connection with building a long time constant integrator for an analog only GPSDO, the primary limitation was insulation resistance of the capacitor. Even the best low dielectric constant C0G/NP0 capacitors were much worse than polypropylene film which was itself was much better than polyester. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
