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

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

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

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

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:

Not only did it find the item,