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Decoding capacitor numbers to find a replacement?

It's kinda tricky decoding the numbers sometimes. It seems like the resistance of the parts is related to the voltage and current ratings.

I think the middle number on these are the batch number and the lower one is probably the part number. I'm wondering if they had a S, S-20 or maybe a S-203 series and the 23 and 10 are related to the current ratings. I think the first part is the part series and the second part is the current rating but I'm not sure where the demarcation line is.

Do you have a DMM. Can you ohm out the parts?
 
I do, I can and I will.

Since I am going to replace or remove these guys, I clipped one leg loose to test. I have been led to believe that will give an accurate reading with one leg still attached.

On the smaller switch - readings fluctuate between 0.7 to 1.0 ohms. Mostly staying around 0.9.
On the larger switch - readings fluctuate between 2.1 and 2.3 ohms. Mostly staying around 2.2.

I think I see a pattern here - or one hell of a co-inky-dink!
 
I thinking those numbers are kinda high. That probably means they have been tripped before because they are known to stay at higher resistance than the OEM value when they try to return to the LOW Z state. That and aging have probably done them in.

Now to figure out what to replace them with. :idea:
 
I have an idea. Try to email TE connectivity and tell them you need replacements and attach that picture with your question.

Hopefully they have somebody there that can decipher that old part number and recommend a modern replacement.

http://www.te.com/usa-en/customer-support/email-us.html?f1=0

EDIT: I just noticed something on that old data sheet. They say they had a special line for speakers that started with SPK. Perhaps the S is the old speaker designation?
 
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Well heck. I thought the 1.0 reading related to the code 10 and the 2.3 reading related to the code 23.
 
I second SoundofSound's suggestion. The marking on the part is the TE connectivity symbol, and it is certainly a polyswitch (PTC). As far as the markings, most of the time the hold current rating is part of the marking, and sometimes the maximum voltage and the transistion temperature. But I can't make heads or tails of the markings on your parts.

Terry
 
I sent an email to TE to see if they will tell me how to decode the part number or just give me modern replacement part numbers. I will certainly let everyone know their response.

Thanks to all who played "Name That Part"! The depth of knowledge and willingness to share on AK is phenomenal.
 
When I suggested a Varistor, I've thought in a polyswitch too, but the polyswitches I know are always light brown, or "caramel" colour...

I agree, the Ampere rating is related to size. 0.9A is like 9 or 10mm diameter.

Using a smaller one won't hurt, it will cut the power earlier. I use 0.75 or 0.9A in tweeters
 
Hello again!

Heard back from TE and here is what they were able to provide.

Part 20310 had an ihold of 2.45A and a ltrip of 4.62A at 20°C. 50V/40A max operating voltage and current.
Part 20323 had an ihold of 1.85A and a ltrip of 3.43A at 20°C. 50V/40A max operating voltage and current.

Looking at Mouser and DigiKey it looks like I can't hit the exact part characteristics. What are the most important specs here - I would think the itrip? Not really sure what ihold means?

On the 20310 part, I can get ihold at 2.5A and the itrip of 5A, 60V/40A max. That's a little over spec on itrip but is it close enough not to be an issue?

On the 20323 I can nail ihold at 1.85A but itrip is a little high at 3.7A - again 60V/40A max.

I may could do better on itrip & ihold if I could relax the voltage and current minimums, but I am not sure if that is wise or not.


Any thoughts and/or suggestion? I am ready to order parts and move forward!
 
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