P6KE16A 'transient voltage suppresor' - advice ?

Do a search on Wikipedia for TVS diode, that should give you some information.

Shaun

On Sat, 9 Jan 2010 17:51:48 -0600, "Shaun" put finger to keyboard and composed:

What is a Silicon Transient Voltage Suppressor and how does it work?

- Franc Zabkar

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Please remove one 'i' from my address when replying by email.

.pdf

But,unlike zeners , are they guaranteed to go short circuit if they end up in what becomes a sustained overvoltage rather than just a transient situation ? or 2 different clases of VTS ?

On Mon, 11 Jan 2010 08:25:42 -0000, "N_Cook" put finger to keyboard and composed:

I watch various hard drive forums. HDs nowadays use TVS diodes on their +5V and +12V rails. A sustained overvoltage from, say, a 19V laptop adapter always (?) shorts the 12V diode, unless it is protected by a fusible zero-ohm resistor.

- Franc Zabkar

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Please remove one 'i' from my address when replying by email.

up

A zener would normally burn up/ go open circuit in overvoltage but do VTS normally (but not guaranteed) go short thus providing crowbar protection if fuse/fusible R/ current limiting/ps shut down, upstream. 80 percent/90 percent/ 99 percent of the time go s/c rather than o/c , any guesses/knowlege?

And for completeness, in general terms. I know it must vary with manufacturer/type of overload (eg from repeated short term overloads/various amount of one-off overload, surges rather than transients etc) I think I've only ever come across 3 failed VTS, all s/c, so 80 percent failing s/c , generally say Over the years I would , gut-feeling , say zeners fail o/c 80 percent of the time. Anyone else's experiences to add here for a concensus view from experience?

Some interesting failure mode comparisons on this ap note

On Mon, 11 Jan 2010 08:55:58 -0000, "N_Cook" put finger to keyboard and composed:

I would think that they would go s/c, but will eventually go o/c if the fault current is sustained.

The TVS failures I've seen have all been s/c because the PSU has shut down.

- Franc Zabkar

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Please remove one 'i' from my address when replying by email.

thanks for all the replies. so, seems like this is purely for protection while zeners can be sued for regulation. the one here is s/c and the psu was utterly dead. there are a few bulged caps and its a cramped crappy design so no real mystery. it must have gone s/c as the rails crept up and it could no longer handle the suppression of transients. Owner reported strange noises before it died.

-B

Hello B,

Here's a description for TVS diodes that talk about the difference between them and zeners.

Shaun

Another question: what do the suffixes 'A' or 'CA' refer to? I ask because I have been unable to find the exact replacement but have a P6KE20CA. Not ideal, since the voltage rathing is 4v higher but I assume it's better than nothing. Or would this be a bad idea due to the different suffix? cheers.

-B

*-*%22+%22+suffix-CA-denotes-*-*

*-*%22+%22+suffix-C A-denotes-*-*

But what is the function of *-* in the search string ?

N_Cook wrote:

Wildcards. Google (alone, AFAIK) allows those. When the results page appears, the words that appear in the phrase where the asterisks are[1] will be highlighted (along with the requested text).

...and, of course, the day after I post the link, Google stops indexing the page. 8-(

Note also that when properly rendered on a schematic, a CA device will have a nose-to-nose symbol reprentation. . . [1] A hyphen is a valid word separator (as is a period).

so far I've been unable to find the part in question. As I need to return this unit soon, I'm loath to leave it without some form of o/p protection, is there anything strightforward I could add to this psu to protect the appliance 'downstream'? possibly some form of crowbar at least.

-B

Plenty of them in stock :

No minimum order , but I dont know if they do international orders.

This describes Igor's Spam-Free Custom Search:

You should bookmark the Google page.

Not only did it find the item,

4 entities thought it was worthwhile to pay for an ad for that term.