[Amps] HV lytic max V ratings..some notes.

[Ron Youvan]

> I was told that too, but never heard any real proof. The idea was that
> an electrolytic is not a static (pun intended) component. The
> electrolyte is chemically active and will gradually deteriorate if not
> run near it's rated working voltage.

> Possibly just an old wive's tale. If anyone has any authoritative
> source, please post it.

   I was taught the applied Voltage developed an insulating layer on one of the foil surfaces 
{similar to anodizing} in contact with the electrolyte, the thickness is proportional to the 
Voltage. (on the surface of the foil with one polarity of applied Voltage)
   If the surface is "formed" (or maintained) at a lower Voltage the capacity will be higher because 
the surface coating is thinner.

   If a long unused electrolytic capacitor (with a greatly reduced operating Voltage) is SLOWLY 
"re-formed" up to the original operating Voltage the original working Voltage and capacity will be 
restored.  (if nothing else is wrong with it)
Chemical impurities will reduce the capacitance and increase the leakage and series resistance.
Loss of moisture in the electrolyte will reduce the capacitance and how knows what else.
   Reforming long unused electrolytic capacitors with a controllable power supply with a output 
mil-ammeter is probably the best way to do it.   (when the current drops to zero, raise the voltage 
slightly)
-- 
    Ron  KA4INM - The next election, I know what is going to happen, I'm going to help.