ID'ing 1979 TRW film cap type?

Hi:

I have a handful of old axial (date code 7932) TRW film caps, series JF-91. No info on the successor company ASC's web site, no response to inquiry.

I figure at worst polyester/mylar...

They don't strike me as 'large', so I doubt they are a better film type.

For example, marked
JF-91
0.22 10%
100 VDC
162610

9.5 mm diameter, 25 mm length.

Unless someone here recognizes them specifically, um, I'll call them 'film caps'.

Thank you!

Murray
 

GrampaDave

Member
2011-02-13 11:27 pm
Adding info to old thread. "JF" means this cap was OEMed by John Fluke company, "91" is the year and 162610 is the Fluke part number. My Fluke 887A AC/DC Differential Voltmeter had a circuit board retrofit for the Null Detector amplifier. The new board uses this cap in the input RC filter. This application requires high insulation resistance and low dielectric absorption, so the material is probably either polystyrene or polypropylene.
 
Hi:

I have a handful of old axial (date code 7932) TRW film caps, series JF-91. No info on the successor company ASC's web site, no response to inquiry.

I figure at worst polyester/mylar...

They don't strike me as 'large', so I doubt they are a better film type.

For example, marked
JF-91
0.22 10%
100 VDC
162610

9.5 mm diameter, 25 mm length.

Unless someone here recognizes them specifically, um, I'll call them 'film caps'.

Thank you!

Murray
Yeah...good point...almost self-evident - not sure why I didn't think PS or PP...maybe I was fishing to see if someone knew for certain.

Because they're only 100 V, I'd lean toward PS.

Don't have enough to cut one open, but I don't really need to...just a curiosity.

I accidentally discovered some tin film/foil capacitors by disassembling...dull grey compared to metallized. Touched with a soldering iron and it disappeared...

I'll just use them.

Thanks
 
PS and PP also have very low dissipation factor and low temperature coefficient, but my application doesn't care so I didn't think to say it.
It's more curiosity than anything else for me. I have never encountered a Teflon capacitor in the wild. At a previous job a group of polymer scientists visited to see one of their custom products in use.

I asked on a whim if there were any easy ways to identify polymers unrolled from capacitors. The one guy rattled off so many visual, audible and burnt smell descriptions I had to stop him & get a notepad! 1986 or so, & I've forgotten some. I don't do capacitor surgery much anymore. It's easier to buy what I want anyway. Just a capacitor hoarder, I guess.