05-09-2025, 10:33 AM
I think all the dodgy bi-polar electrolytics I've replaced were late 1960s and also 1970s,
However the two colour plastic cased Plessey polarised ones all seem to fail too.
The oxide layer on electrolytic is the dielectric and on a regular type it will gradually dissolve / gain holes with lack of use or reverse polarity. A current limited correct DC voltage re-oxidises the surface. High ESR is usually due to the electrolyte drying out or contamination and the electrolyte limits the AC component of the current possible.
I can't see how a bipolar electrolytic can be as reliable as polarised types, and certainly any electrolytic is less reliable than ceramic or plastic dielectric.
However the two colour plastic cased Plessey polarised ones all seem to fail too.
The oxide layer on electrolytic is the dielectric and on a regular type it will gradually dissolve / gain holes with lack of use or reverse polarity. A current limited correct DC voltage re-oxidises the surface. High ESR is usually due to the electrolyte drying out or contamination and the electrolyte limits the AC component of the current possible.
I can't see how a bipolar electrolytic can be as reliable as polarised types, and certainly any electrolytic is less reliable than ceramic or plastic dielectric.
