At 04:25 PM 7/21/2001 -0700, 2 wrote:
> >Why not the ceramic (cement) type Rich ? Reliability ? Shrapnel if an
> >event occurs ?
> >
> >Tnx....Phil
> >
>/\ To be successful, a glitch resistor must not break down internally
>during a major fault. If it does, a metal-vapour arc takes place -
>which limits the V-drop across the resistor to c. 20v instead of the
>needed several kV. Thus, the desired ability to limit current to a
>finite value is lost. Shrapnel and internal breakdown are problems with
>ceramic-type resistors. To find out if a glitch resistor is up to the
>task at hand, (Note: the meters and their shunts should be protected
>with suitable glitch-diodes). short the anode supply to ground with a
>large plastic handle screwdriver. If there is a loud noise, the circuit
>breaker opens, there is no sign of damage, and the ohms are unchanged,
>the glitch resistor did its job.
So, under fault conditions the ceramic ("cement") resistors are known to
be prone to arcing/explosion/etc whereas the glass coated resistors are not
? (or are less prone ?)
Tnx....Phil
>cheers, Phil.
> >
> >
> >>- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
> >>end
> >>
> >>
> >>--
> >>FAQ on WWW: http://www.contesting.com/FAQ/amps
> >>Submissions: amps@contesting.com
> >>Administrative requests: amps-REQUEST@contesting.com
> >>Problems: owner-amps@contesting.com
> >
> >
> >
>
>
>- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
>end
>
>
>--
>FAQ on WWW: http://www.contesting.com/FAQ/amps
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|