Identify if its a GDT or TVS

[joeqsmith]

Glows like a GDT, arcs like a GDT, clamps very slow like a GDT..  Did finally get it to come apart.       

https://youtu.be/0thOfk4I3qs?t=2278

[joeqsmith]

I did write the person who commented on the YT video about it being a TVS.  Basically, I am looking for a suggested part number.   I have no doubts that a TVS could be found in this type of package but they do appear rare.  Not something I would expect to see in a commercial grade modem when plastic packages are widely available. 

[wraper]

I did write the person who commented on the YT video about it being a TVS.  Basically, I am looking for a suggested part number.   I have no doubts that a TVS could be found in this type of package but they do appear rare.  Not something I would expect to see in a commercial grade modem when plastic packages are widely available.

TVS/zener at least do come in this package. Find at least one GDT part number that comes in such package as well.

[floobydust]

I don't see a need for glass-packaged TVS as there is no gas envelope, like in a GDT.
Hermetic-packaged TVS are MIL spec. by Sensitron.

[wraper]

I don't see a need for glass-packaged TVS as there is no gas envelope, like in a GDT.
Hermetic-packaged TVS are MIL spec. by Sensitron.

Then why tons of diodes and zener diodes come in glass package?

[floobydust]

Small switching diodes in glass hermetically-sealed packages are widely available, like DO-35, DO-41, MELF etc. I don't remember ever seeing TVS in glass packages.

I think the difficulty is to gas-fill these with say, neon to make a GDT. Or to make these larger for more power handling, for a big die (TVS) or electrodes (GDT).

joeqsmith's part, might have been:
Mitsubishi DA53
Ruilon china RL501 series 0.5kA 2mm dia. x 4mm.

[joeqsmith]

Small switching diodes in glass hermetically-sealed packages are widely available, like DO-35, DO-41, MELF etc. I don't remember ever seeing TVS in glass packages.

I think the difficulty is to gas-fill these with say, neon to make a GDT. Or to make these larger for more power handling, for a big die (TVS) or electrodes (GDT).

joeqsmith's part, might have been:
Mitsubishi DA53
Ruilon china RL501 series 0.5kA 2mm dia. x 4mm.

They are both axial, not a MELF.   Rare parts in a commercial product would make no sense at all.

[floobydust]

It makes sense as there is no impulse standard for cable modems that I know of. What size GDT is suitable?

GDT's meet Telecom and Mains standards such as UL1449, UL497B, FCC Part 68 etc. so they are sized large.
A tiny GDT is off the radar and has no approvals, maybe a 0.5-1kA rating.

RLM501 MELF 0.5kA 2.1mm dia.
RLM102 MELF 1kA 2.8mm dia.

[joeqsmith]

Yes, GDTs in a MELF package seem common.  I have not heard back from the person who posted on the YT video.  Waiting to see this glass MELF TVS they feel would go into a cheap modem. 

[floobydust]

First time to see small GDT; in Sanwa PM300 DMM? https://www.eevblog.com/forum/testgear/aneng-302-pocket-meter-by-voltlog/msg1737086/#msg1737086

In your testing, I wasn't sure if it (small GDT) could handle a Cat. III impulse.

[joeqsmith]

First time to see small GDT; in Sanwa PM300 DMM? https://www.eevblog.com/forum/testgear/aneng-302-pocket-meter-by-voltlog/msg1737086/#msg1737086

In your testing, I wasn't sure if it (small GDT) could handle a Cat. III impulse.

The question mark does not appear  to follow a question.  I have never shown a category III impulse and have no way to create it.  Someone had made a similar comment about my tests damaging MOVs.   Perhaps you do not have an understanding how most of the meters I have looked at are designed.  I suggest reading post #2411

https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/2400/

Sounds like Wraper is not having any luck finding a TVS that they feel would have been a replacement.  I'm not surprised as it seems it would be a special part.   Looking at the YT metrics, it did get a DV from someone in Latvia.       Perhaps someone was upset that I was showing too much data.

[floobydust]

It's many questions that little GDT raises, RIP. I understand multimeter protection circuits and 61010 well enough to get equipment designs certified.

The Sanwa PM300 using a slightly larger GDT with no MOV's, "The world's only CAT IV IEC61010 rated true pocket sized multimeter"

Seems strange a little GDT can pull it off, no MOV's required? Zotek and ANENG jump on board.
You and I know the let-through/follow-through current would be a catastrophe in this crappy scheme.

Looking at the PM300 approvals test report it appears fake- 61010 ESD tested to 4kV, but no mains transient testing. The PM300 product manual states that wonderful term "designed to" which is not certified to...

You think a little GDT can achieve multimeter 61010 approvals?