[Amps] Glitch resistors

[Gary Schafer]

Richard wrote:

> >
> >
> >Richard wrote:
> >
> >> >
> >> >On Mon, 4 Mar 2002 22:02:43 +0000 "Ian White, G3SEK" <G3SEK@ifwtech.com>
> >> >writes:
> >> >
> >> ><snip>
> >> >
> >> >Hi Ian,
> >> >
> >> >> Can we identify a specific range of US-made resistors, for the
> >> >> record?
> >> >
> >> >  Here are some real pulse rated types... not just ceramics that (may)
> >> >happen to survive the event.
> >> >
> >> >  Kanthal Globar (who acquired the Carborundum product line) makes a good
> >> >assortment -- their resistors are rated for both pulse voltage and
> >> >energy.  Take as look at the AS parts.
> >> >
> >> >  Ohmite has a new line that would be suitable for the application with a
> >> >pair in series -- look for the AY & AZ prefix
> >> >
> >> €  To test a glitch resistor, short the HV+ to gnd.  [Before doing this
> >> test, install suitable glitch diodes across the meters and across the
> >> grid current and anode/plate current shunt resistors]  The glitch
> >> resistor should not exhibit physical damage or a change in R.  If the
> >> glitch resistor does pass the test, discard it, install two such
> >> resistors in series, and repeat the test.
> >>
> >> -  R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
> >> www.vcnet.com/measures.
> >> end
> >>
> >>
> >
> >Isn't the idea of a glitch resistor to act as a fuse ? Don't you want it to
> >open on a glitch?
> >
> €  When an overloaded glitch resistor is in the process of exploding, a
> metal-vapour arc briefly takes place.  The V-drop across such an arc is
> c. 20 volts.  Thus, the arc does not do much to limit peak current flow,
> which is/was the primary job of the glitch resistor,  With no defined
> limit on peak fault current, tube damage is likely.
>
> cheers, Gary
>
> -  R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
> www.vcnet.com/measures.
> end
>

Ok that makes sense.

Thanks
Gary  K4FMX