"N_Cook" wrote in message
...
On 03/05/2014 21:36, Jon Elson wrote:
N_Cook wrote:



Would "suicide diode" be a valid term for searching within a supplier
site?. I've come across guaranteed VTS/diode failure to short and never
open, before , but not able to nail it down. Would you know of any
VTS/diode type number that is definitely made for this purpose?
No, that's my own description. Digi-Key part
SA5.0ALFCT-ND is a representative part, although not the one
I've seen in a particular power supply. (I can't find the
part number of that unit right now.)

Jon


I still cannot find specifically stated , designed to fail short circuit
in any associated datasheet for that TVS. Of course any device might fail
short or even frequently fail short but I've still never found any TVS
designed and stated as such to fail short for safety purposes, ie as you
succinctly term such a theoretical device , a suicide device


Panasonic vcr's from the '90s had ordinary 18v 1-watt zeners across the
output of the 15 volt line. When the supply lost regulation, usually due to
bad caps, the zener would short quite reliably. This was supposed to blow
the fuse but generally took out the switcher transistor as well. Sony's were
better designed - the zener would short, and the switcher was so far out of
it's resonant range it would simply stop running with no other damage.

Mark Z.