1
\$\begingroup\$

Please help identify this component. It is cylindrical, with an axial configuration, and no obvious indication of which end is which. The writing on it is: K25U 104M 50V 8502

The 104M makes me think it is a 0.1 uF capacitor, but, in my extremely limited experience, this is an unusual form factor for a capacitor. My googling for images of similar looking capacitors has turned up nothing.

Photo of the component

\$\endgroup\$
1
\$\begingroup\$

I think your guess is right. From the code and appearance, it should be: an unpolarized, 100nF, ±20% tolerance (from the "M"), 50V capacitor. That form factor is not unusual for older capacitors, and the physical size makes sense for a 100nF 50V cap.

Also, if that "8502" is a date code, that would be January 1985!

To verify (or at least narrow down) whether it's a capacitor or not, you could check resistance in both directions. If there's no conductivity in either direction, it's very probably a capacitor. If not, then it's either a broken capacitor or something else entirely.


Edit: For completeness, a datasheet search for "K25U" turns up a couple things:

  • K25UF, a 3A, 2.5kVrwm diode, axial package, from Voltage Multipliers, Inc. Highly doubt it's this.
  • A series of ceramic disc capacitors, safety class X1/Y2, part no. SxxxK25U2MS6.K7. Package doesn't match.
  • Semikron SK25UT, an 800V thyristor module. Definitely not that.
\$\endgroup\$
1
\$\begingroup\$

It appears to be an axial molded ceramic capacitor - 100nF +/- 20% (M) 50 V rating.

It was likely manufactured in January of 1985.

Here (page 106) you can see some similar types.

I don't see a datasheet reference to that part number on the net, but I would guess it might be Z5U dielectric from the 'U' in the part number, value/rating and the age. If so, you could expect it to be very unstable with temperature and time (and change drastically with applied voltage)

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.