approx worst ESR for new lytics:
3.3uF / 60V = 6 ohms 1uF / 60V = 16 ohms 2.2uF /50V = 10 ohmsyour tants are far better
NT
Tantalum capacitor ESR
Mar 20, 2020
29 Replies
More is OK if surge current (namely dV/dT) is limited.
1/3 seems to work no matter what the rail can do.
John Larkin Highland Technology, Inc
The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
A square wave generator and a scope makes nice ESR measurements.
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John Larkin Highland Technology, Inc
The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
That would take up way too much real estate. I have upped the voltage rating on the replacements I've bought from 35V to 50V and even 60V where there was no correct C value for 50V. Even going from 35 to 50, which is not much over a third, and the axial leads have to be bent back on themselves to fit the available space the 35s formerly occupied. So 100V ones are out of the question I'm afraid!
Polymer aluminum caps now come up to 250 volts.
What's great is that they also go down to 2.5 volts.
John Larkin Highland Technology, Inc
The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
Last time I measured tant esr (4.7 or 10 uf) 35V it was about
0.6 ohms... some more, some less, in a batch. If you bought a batch take one or two up slowly to the voltage limit, (maybe with series R)George H.
heat treat them post soldering is another option.
NT
Heat is what damages them. Re-forming them with a current-limited supply is the ticket. See
Cheers
Phil Hobbs
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com
When I talked to Kemet about it they mentioned heat but not as the exclusiv e problem. They said this is mostly a facet of this type of capacitor and should be dealt with by underrating and/or using current limiting on initia l power application. They have an app note on this. If you want I can dig it out.
Rick C.
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yes, my bad.
NT
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