Capacitor codes

[Paul Hovnanian P.E.]

I've got an axial lead polarized cap with the following markings:

1K
50V

Its about 0.1 in diam x 0.3 in long

Now, I've seen 1K as a picofarad value, which would make this a 1nF cap. But
this thing is big compared to other caps of this rating. A .001uF 1KV
ceramic is much smaller. And this doesn't make sense in the circuit its in.

In other contexts, the K letter code defines the tolerance. But that usually
follows a three digit value code.

So, what is it that I'm looking at? The cap is bad, or I'd throw it on a
meter and figure it out.

--
Paul Hovnanian mailtoaul@Hovnanian.com
------------------------------------------------------------------
A mathematician is a machine for converting coffee into theorems.

 

[William Sommerwerck]

As you say, Paul, the value could be various capacitances depending on what
coding was used. From the size, I would suspect that 1uF would not be
unreasonable, but that depends on the 'type' of cap it is [electrolytic or
tantalum or ?]. I don't suppose there is another similar cap on the board
that IS good that you could measure. Even if its value is somewhat
different, it would allow you to decode the markings.

===========================

I was going to suggest it was a tantalum, but I checked a catalog, and both
the capacitance and voltage are too high. And I've never seen an axial-lead
tantalum.

 

[nesesu]

On Friday, May 25, 2012 7:28:06 PM UTC-7, Paul Hovnanian P.E. wrote:

I've got an axial lead polarized cap with the following markings:

1K
50V

Its about 0.1 in diam x 0.3 in long

Now, I've seen 1K as a picofarad value, which would make this a 1nF cap. But
this thing is big compared to other caps of this rating. A .001uF 1KV
ceramic is much smaller. And this doesn't make sense in the circuit its in.

In other contexts, the K letter code defines the tolerance. But that usually
follows a three digit value code.

So, what is it that I'm looking at? The cap is bad, or I'd throw it on a
meter and figure it out.

--
Paul Hovnanian
------------------------------------------------------------------
A mathematician is a machine for converting coffee into theorems.

As you say, Paul, the value could be various capacitances depending on what coding was used. From the size, I would suspect that 1uF would not be unreasonable, but that depends on the 'type' of cap it is [electrolytic or tantalum or ?]. I don't suppose there is another similar cap on the board that IS good that you could measure. Even if it's value is somewhat different, it would allow you to decode the markings.

Neil S.

 

[Doug White]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in
news:jpr2b9$n09$1@dont-email.me:

As you say, Paul, the value could be various capacitances depending on
what coding was used. From the size, I would suspect that 1uF would
not be unreasonable, but that depends on the 'type' of cap it is
[electrolytic or tantalum or ?]. I don't suppose there is another
similar cap on the board that IS good that you could measure. Even if
its value is somewhat different, it would allow you to decode the
markings.

===========================

I was going to suggest it was a tantalum, but I checked a catalog, and
both the capacitance and voltage are too high. And I've never seen an
axial-lead tantalum.

In the old days, axial leaded tantalums were the norm. Usually had a metal
case.

Doug White

 

[Paul Hovnanian P.E.]

Ian Field wrote:

"Paul Hovnanian P.E." <paul@hovnanian.com> wrote in message
news:iPydnQuYb8r0-13SnZ2dnUVZ_jEAAAAA@posted.isomediainc...
Tim Williams wrote:

Either 1uF, or the point is invisible making it 0.1?

Metal case something, or regular aluminum electrolytic? If it's not
aluminum then probably dry tantalum.

Tim

I'd like to join the consensus saying "1" - maybe a hard to read point,
and offer the opinion that "K" could be a tolerance code.

No hard to read point. I checked with good magnification.

K as a tolerance code agrees with some stuff I've found on line.

But here's the acid test: The circuit works with a 1uF cap. So this means 1K
is either 1E3 nF or 1uF and the K is tolerance (10%). Either interpretation
would suggest that electrolytics (or polarized caps) use a different base
value than ceramics and others (which use 1 pF).

Aren't standards great? That's why we have so many.

--
Paul Hovnanian mailtoaul@Hovnanian.com
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Time is the best teacher; Unfortunately it kills all its students.

 

[William Sommerwerck]

Might I ask whether it would be useful to determine what /type/ of capacitor
this is? That would go a long way in deciding its value.

 

[Paul Hovnanian P.E.]

William Sommerwerck wrote:

Might I ask whether it would be useful to determine what /type/ of
capacitor this is? That would go a long way in deciding its value.

We (the accumulated wisdom of s.e.d and s.e.r) seem to think its an aluminum
electrolytic. Long odds on a tantalum.

--
Paul Hovnanian mailtoaul@Hovnanian.com
------------------------------------------------------------------
Dyslexics are teople poo!