[Top] [All Lists]

[AMPS] construction of parasitics

To: <>
Subject: [AMPS] construction of parasitics
From: (Phil (VA3UX))
Date: Sun, 22 Jul 2001 09:45:15 -0400
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 ?)


>cheers, Phil.
> >
> >
> >>-  R. L. Measures, 805.386.3734,AG6K,
> >>end
> >>
> >>
> >>--
> >>FAQ on WWW:     
> >>Submissions:    
> >>Administrative requests:
> >>Problems:       
> >
> >
> >
>-  R. L. Measures, 805.386.3734,AG6K,
>FAQ on WWW:     
>Administrative requests:

FAQ on WWW:     
Administrative requests:

<Prev in Thread] Current Thread [Next in Thread>