[ARC5] Reforming Electrolytics attached as PDF

[Bob kb8tq]

Hi

If you “re-form” an electrolytic to a higher voltage than it originally was set up for, 
you *may* have less total capacitance than the original part. (thicker dielectric 
= wider spacing = less C). The same thing may be true in reverse (lower voltage
means more C). 

Bob

> On Mar 19, 2018, at 9:27 AM, Roy Morgan <k1lky68 at gmail.com> wrote:
> 
> Bob,
> 
> One of the most experienced members of the Collins community reports a very high success rate reforming original electrolytics in Collins radios:
> 
> His method is to reform the electrolytic VERY SLOWLY, with a B+ source limited to FIVE MA., while monitoring the Cap voltage. Patience is essential. Reforming is at its limit when the voltage ceases to rise with increased current. 
> 
> This is NOT the common “bring it up slowly on a variac” method!
> 
> My experience using the 5 ma max method is also that the majority of electrolytics will re- form to a useful voltage. 
> 
> I would expect that a cap that reforms only to a voltage lower than its rating would work ok at a voltage lower than the reforming voltage by a healthy margin. 
> 
> I don’t have an ESR meter, but I expect that using one and the above method would take all the guessing out of working with old and new electrolytics. 
> 
> Note: I find that lower voltage electrolytics (6 to 30 volts) reform to voltages a lot higher than their rating. 
> 
> Roy sends.
> 
> On Mar 19, 2018, at 8:27 AM, Robert Eleazer <releazer at earthlink.net <mailto:releazer at earthlink.net>> wrote:
> 
>> I've been evaluating electrolytic caps by applying a charge and then noting the results. 
>> 
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