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What is ripple current rating of this film capacitor?

Flyback

Well-Known Member
Hi,
What is the ripple current rating of this film capacitor? (at 50/60 Hz and 20kHz)

MAB MKP 12/400 12UF +-5% 400V AC 30000h.....

Here is its "datasheet"
Attached also is datasheet...none tell the ripple current.
(it doesnt weigh 1Kg)

Attached also is datasheet...none tell the ripple current
 

Attachments

  • MKP_400_0612_final.pdf
    334.3 KB · Views: 27

rjenkinsgb

Well-Known Member
Most Helpful Member
Film capacitors don't have a ripple current rating as such; the limit is a dV/dT figure, usually volts per microsecond.

You can calculate the equivalent current in a specific application from that, the capacitor value and the signal frequency or sum of the frequency components.

For example, a present series of similar motor run style MKP have ratings around 15 - 20V per uS.

>google<
I've just found a vintage Siemens data book; see page 393 - the MKP motor caps in that are rated 10V/uS.


ps. Similar MKP motor caps, brand new, cost a lot less than that ebay one!
 

Flyback

Well-Known Member
Film capacitors don't have a ripple current rating as such; the limit is a dV/dT figure, usually volts per microsecond.

Thanks, it'll be used in this converter attached, in LTspice
Its 30Arms of ripple current, at 20khz, but the highest V/us is about 3v/us, so it will be OK?
I thought the equivalent ripple current was VAC/Xc = 400/Xc

Xc for 12uF at 50Hz

...gives 1.5A.....so thats well below 30A, and i would have thought bad news for us?
 

Attachments

  • HALF BRIDGE__20KHZ _High leakage L.pdf
    198.5 KB · Views: 26
  • HALF BRIDGE__20KHZ _High leakage L.asc
    19.9 KB · Views: 20
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