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What type of Capacitor is this??

R

richard_crl032

Member
Found the below capacitor in the 12V input stage of my amplifier without manufacturer name and could not make up "36 X3" marking:

http://www.flickr.com/photos/41902319@N06/3894752877/

It looks like aluminium electrolytic type but would appreciate if I can hear it from someone who had seen or used them.

What is the use of this plastic overmolding if indeed the usual aluminium electrolytic cap??

Thanks.

Richard
 
No recognition here. If we assume it is 22uF then probably a tantalum. Does it have any polarity marking? Does it connect between the power rail and 0V? If not is it in the input path?

I take it it's busted.

David
 
Hi David,

Thanks for the response.

As seen from the photo in the link, there is clear marking "+" and "-" and if you break away the plastic casing, there is a typical cylindrical std e'lytic cap-looking piece.

It is located right after the +12V input as seen in the following photo on the left input power PCBA:

http://www.flickr.com/photos/41902319@N06/3860292559/

and yes, these are leaking and had shorted at some location and hence my hope to know what they are and have them substituted.

For now, I am contemplating on using the United Chemi-con KME series with very low leakage current of 0.001CV or 2uA whichever higher as shown here:

http://www.chemi-con.com/files/KMEKMEH9.pdf

Any further comment would be most appreciated.

Regards,

Richard
 
Do the leads protrude beyond the plastic case Richard ? they appear to be flat wire leads as opposed to round wire usually used for thru-hole.

They are definately Electrolytic caps and if the leads are indeed flat and do protrude then I would suggest that the plastic case is there to ensure the cap is flat to the PCB surface when used as a surface mount device, which through all intense and purpose is what it appears to be. I believe you could safely replace them with Tant Beads if they are for AC coupling, or betters still Wet Tants, and if they are for de-coupling duties then a standard electrolytic will do the jobm, use a good low ESR type.

Paul
 
Hi Paul,

Thanks ! You are right ... I took another look at the capacitor and indeed the leads are flat and they wrap around the plastic case to be used as a surface mount device .... not thru' hole as commented in the first photo.

This car amplifier is using the top of previous Muse series FA capacitors in most of the locations and I believe there is some reason for use of this 22uF 16V electrolytic cap instead of Tant caps or wet tants e.g. mentioned low leakage current of UCC KME?

Is there any possible reason(s) to do so as I am not clear on the advantages/disadvantages of these different cap types ?

BTW, are these electrolytic cap with plastic case available in the market?

Regards,

Richard
 
Hi Malcolm,

Thanks for the effort on the check on Farnell site.

These SMD types is interesting especially the Sanyo which has some excellent specification. However, the leads of the capacitor runs along the side of the plastic housing or about 5mm pitch against these SMD types that have their leads facing each other at much smaller gaps.

Still thinking of how to use these SMD types electrolytic caps especially the Sanyo's SVP but not likely I can do so.

Any more similarly capacitors in the market with squared housing shown in the first photo?

http://www.flickr.com/photos/41902319@N06/3894752877/

Regards,

Richard

PS: To all, Thanks for all the good advices ..............
 
Richard, I have never seen those plastic surrounds used anywhere on hi-fi so I would imagine it is for some protection against vibration when used in a car-audio installation, just my thoughts. The Sanyo SVP's are a good alternative, they are Low ESR and have flat leads for SMD pads, the black plastic base on the SVP's is removeable, just straighten the leads and pull it off, this will allow you to bend the leads in the position you need to suit the pad layout on your car amp, but I think the leads will be too short. Why not simply buy some standard thru-hole Low ESR caps and use the plastic surround and feed the leads through, I really don't think that the plastic surround is that important provided that the caps do not touch each other then they will be fine IMHO ;)
Paul
 
Hi Paul,

Thanks again for the thoughts and comments.

Will proceed with thru' hole UCC KME low leakage current option and use hot melt to provide the similar security against vibration. The flat side of the leads of the Sanyo SVP is in the wrong direction to the SMD pad and will be difficult to secure unless is can somehow remove the base as advised and twist the leads 90 degrees off .... will still order some to try.

Believe these power related capacitors have negligible impact, if any at all, on the sound quality of this car amplifier.

Regards,

Richard
 
I think its a fairly standard aluminium electrolytic specifically repakaged to be used on boards designed for surface mount components so that it mounts the same side as everything else on a single sided board.

My Benchmark DAC has loads of them. It will just be a fairly ordinary 22uf cap
 
Hi Colasblue,

Thanks for the confirmation as also advised by Paul and Malcolm. My ignorance for not having seen these before and hence the thread for help which had left me with no further doubt.

Thanks to all.

Regards,

Richard
 
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