Have you ever seen this type of cap?

[david90]

The cap looks like this

**broken link removed**

but it has a slit that start from the center point of the cap and goes all the way up to the top. You can see through the slit.

What type of cap is this and why does it have the slit? Initially I thought the cap blew up and cracked but the slit is too perfectly straight.

 

[ckshivaram]

these are multilayer ceramic capacitors in short (MLCC)...... its not blown up capacitors.. the construction is like that only/..........

 

[keith1200rs]

Are they all like that? They are resin dipped ceramics and it sounds like they are not dipped correctly. The resin dipping is a protective coating.

Keith

 

[david90]

There's one one cap that looks like that on the pcb. As for dipping...i'm not sure. Just look at the attached picture in my first post and imagine that somebody take a dremel with a cutoff wheel and cut the cap from top to the mid point. That's how it looks.

 

[keith1200rs]

I think that one just hasn't been dipped properly. It should still work ok.

Keith

 

[betwixt]

I use thousands of them and they are dipped multi-layer ceramics but as Keith points out, the dip should completely cover the internal parts. It will not have any adverse effect on its working but it might make it more prone to handling damage and it certainly means it is less protected from the environment. If you use them in large quantities, I would return them to the distributor and get replacements.

Brian.

 

[Ruslan_Windrivers]

They are just very cheap multi-layer ceramic caps as previous guys said (costs from 3 to 5 cents each ), so don't expect great quality from them.
Right capacitor actually wasn't properly made as it should be sealed as well as left sample.

 

[MikeOhio]

From your description the caps sound like spark gap capacitors. Do a Google search if you need more information.
Mike

 

[betwixt]

Wrong!
These devices are only rated at 50V DC. It is simply a manufacturing error, my guess is it wasn't dipped deep enough in the resin and didn't get it's feet wet.

Brian.

 

[ckshivaram]

i dont think there is any problem in using it as it does not affect the performance unless used in UHF or higher range... the only problem is it would break if not soldered or desoldered properly...

 

[MikeOhio]

Wrong!
These devices are only rated at 50V DC. It is simply a manufacturing error, my guess is it wasn't dipped deep enough in the resin and didn't get it's feet wet.

Brian.

Well Betwixt, since David90 stated that the capacitors in question "looked like" the picture he posted, I assumed that they were similar but not exactly alike. I made my comment based on his description and, since no one else had made mention of caps that deliberately have a slit in the top, I thought I would offer that as a suggestion. Unless I read his description incorrectly, he stated that the slit was a perfect cut that went from the top to midpoint of the cap. A manufacturing error that you described would have the slit running from between the leads upward since the caps are dipped basically upside down. An actual picture of the cap in question would probably have gotten a much more informed response from everyone.
Mike

 

[betwixt]

No offense meant Mike.

The caps in question are the ones photographed and being bandoliered they should be identical, the one on the right should have been rejected by the manufacturer but I suppose its inevitable a few slip through the QA net.
I agree, spark gap capacitors usually have a slit in the center but on the opposite side to the legs and running parallel to them. I've never dismantled one but my guess would be they loop the wire right around the top of the cap, dip it in resin then saw through it to create the gap.

Brian.