Tantalum capacitor

[zoblitz]

After 21 years my RP1 failed yesterday, I plugged to the outlet and then a smoke smell came out of it. I unplugged the RP1 and when I removed the bottom cover of it I realized that the smell was due to a capacitor that had exploded.



The explode capacitor it called C36 and according the schematic C34 (page 5) has the same characteristics of it. In the picture you can read 10-16 on the capacitor and the schematic say 10T.

I think the 16 means 16_V, I suppose the number 10 refer to the capacitance but don't know the units (uf, pf, etc).

Also I was wondering my self can I replace a tantalum electrolytic capacitor with let's say a aluminum one or just with a electrolytic?

Thanks in advance.
RP1BOTTOM.pdf

[52 Bill]

I think the 16 means 16_V, I suppose the number 10 refer to the capacitance but don't know the units (uf, pf, etc).

Also I was wondering my self can I replace a tantalum electrolytic capacitor with let's say a aluminum one or just with a electrolytic?

10uF microfarads, it's just a basic decoupling cap.

A normal electrolytic can be used, but if the original was spec'd as a Tantalum, I'd stick with it.

[Dave H]

If you use a tant use 10u 25V. I've seen lots of tants fail when operated close to their voltage rating.

[The Dude]

If you use a tant use 10u 25V. I've seen lots of tants fail when operated close to their voltage rating.

+1

[Jazz P Bass]

If you use a tant use 10u 25V. I've seen lots of tants fail when operated close to their voltage rating.

Oh yeah, watch the voltage rating.

I had been using a 35V rated cap in a stepper motor drive for years.
If the line voltage went high, the unregulated rail could go above 35 volts.
Never had a problem.

Somewhere along the the line the cap was changed (same manufacturer) & that 35 volts could no longer be exceeded.
Pop went the capacitors.
Not all of them, but enough to choose a 50 volt cap.

[km6xz]

Old Tantalums got a bad rep after they started failing mass in gear made in the 70s and 80s. A lot of them started failing at about 15 years. Newer styles are more stable chemically so there is no reason not to use the same values but modern versions. It must be on a 5 volt digital rail so 10volts is fine.

[g1]

It must be on a 5 volt digital rail so 10volts is fine.

C34 & C36 are on the + & - 12V lines at U32, page 5 of schematic.

[eschertron]

C34 & C36 are on the + & - 12V lines at U32, page 5 of schematic.

So it makes sense that the designer called for a 16v cap.

[The Dude]

C34 & C36 are on the + & - 12V lines at U32, page 5 of schematic.

Thanks for that, g1. I hadn't even looked at the schematic. I just assumed we were talking about the typical +-15V lines (which can often slightly exceed 15v), in which case I would not use a 16V cap. 16V should be fine in this case. The overall takeaway being that you shouldn't run a cap too close to its rated voltage.

[km6xz]

I assumed it was a digital supply since the original was 10 volts based on an early post. For consumer products 16 volt would be used and for commercial and industrial long life units would be 25 volt rated.