TVS used as a zener
in [Design]
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From: John Larkin on 22 Apr 2010 10:04 On Wed, 21 Apr 2010 23:42:41 -0500, "mook johnson" <mook(a)mook.net> wrote: > >"Joel Koltner" <zapwireDASHgroups(a)yahoo.com> wrote in message >news:ubPzn.386506$Hq1.67880(a)en-nntp-04.dc1.easynews.com... >> "John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in >> message news:s3evs5d3j9n01i285ohq0o6pav2b7413b5(a)4ax.com... >>> A transzorb is just a big sloppy zener. Except the bidirectional ones >>> are two big zeners. >> >> I've been told a significant difference is that transzorbs are generally >> designed to fail short-circuit whereas one typically expects a Zener to >> fail open-circuit... > > >I've popped a few different zeners and they fail shorted every time unless I >have enough juice to bend the leads the opposite way they were installed. >:) > Yup. Any diode will fail open if you have the right number of amps available. John
From: linnix on 22 Apr 2010 11:58 On Apr 21, 8:15 pm, "Joel Koltner" <zapwireDASHgro...(a)yahoo.com> wrote: > "John Larkin" <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote in message > > news:s3evs5d3j9n01i285ohq0o6pav2b7413b5(a)4ax.com... > > > A transzorb is just a big sloppy zener. Except the bidirectional ones > > are two big zeners. > > I've been told a significant difference is that transzorbs are generally > designed to fail short-circuit whereas one typically expects a Zener to fail > open-circuit... I would want my zener to fail short-circuit, if I have a choice.
From: Joel Koltner on 22 Apr 2010 12:23 "PeterD" <peter2(a)hipson.net> wrote in message news:9nd0t5th83aghvodb1n22r2tgoruufp5am(a)4ax.com... > I suspect if it failed to short circuit, the failure would be > temporary... <bg> Right, the idea (it was explained to me) is that they're first short and then remain shorted long enough (assuming you've sized it correctly) to blow the in-line fuse.
From: linnix on 22 Apr 2010 12:30 On Apr 22, 9:23 am, "Joel Koltner" <zapwireDASHgro...(a)yahoo.com> wrote: > "PeterD" <pet...(a)hipson.net> wrote in message > > news:9nd0t5th83aghvodb1n22r2tgoruufp5am(a)4ax.com... > > > I suspect if it failed to short circuit, the failure would be > > temporary... <bg> > > Right, the idea (it was explained to me) is that they're first short and then > remain shorted long enough (assuming you've sized it correctly) to blow the > in-line fuse. Correct, I spec my zener: 30W-NO, 50W-SC, 1MW-OC (NO: Normal Operation, MW: MegaWatt)
From: Joerg on 22 Apr 2010 12:31
PeterD wrote: > On Wed, 21 Apr 2010 20:15:36 -0700, "Joel Koltner" > <zapwireDASHgroups(a)yahoo.com> wrote: > >> "John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message >> news:s3evs5d3j9n01i285ohq0o6pav2b7413b5(a)4ax.com... >>> A transzorb is just a big sloppy zener. Except the bidirectional ones >>> are two big zeners. >> I've been told a significant difference is that transzorbs are generally >> designed to fail short-circuit whereas one typically expects a Zener to fail >> open-circuit... > > I suspect if it failed to short circuit, the failure would be > temporary... <bg> > Yup, they achieve proper zener voltage just one more time. For a few picosecond ... *PHOOMP* -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |