Re: 2465B power supply - Sprague 290uF/200V big blue caps

Dallas Smith
 

Hi Valentin,



The safety caps are in my list also, I used plastic. Your choice for the 290uF replacement looks good, my replacement was 25 x 50mm, didn't fit ideally.


Dallas



---In TekScopes@..., <vdonisa@...> wrote :

You're correct, they don't need any "ultra low Z" replacement, I was just pondering what happened to those series of caps. Guess they were not easy to do right and since polymer probably makes more money too....

I eventually ordered a pair of United Chemicon LXS 330uF/400V in 25/40mm size - these should certainly fit well from a size perspective.

Now I'm debating the X2 and Y2 safety rated caps - paper or polypropylene? Just found a manufacturer (Wima) that does both in proper size and I compared the datasheets. Paper has higher DF (10x more) but can take more dV/dt (10x). Failure rate also slightly in favor of paper. Except that I've seen so many bulged paper ones while plastic seems to be stable. Also measuring old ones, paper seems to increase DF dramatically over time while plastic is more stable.

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