"Stan" wrote in news:1171550716.139540.131150
@k78g2000cwa.googlegroups.com:

If anyone can ID the component shown here http://
www.stanleyes.ndo.co.uk/ i'd appreciate it.

Below is further information that i posted to another group before i
had photo's:

.....

I'm concerned for the health of the component because during operation
i can see a small blue spark across the dark cylinder contained within
the translucent body. This seems to occur at random intervals. During
operation the component has approx 70V AC across it although i suspect
this is only noise picked up by the degauss coil. To test this theory
i connected a 100K resistor across the suspected TVS and observed that
the voltage drops instantly to zero.

I desoldered the component and using my DMM found its resistance to be
greater than 20MOhm. Probably because its knackered (i suspect!)

IF it were two diodes joined in that way, it would only go into conduction
when the reverse breakdown voltage of the back biased diode was exceeded,
so it would appear open to your ohm meter.

You could try replacing it with two diodes oriented the same way. Pick
diodes with a low enough reverse breakdown voltage to protect the relay
terminals from pitting and welding while being high enough to withstand any
'normal voltages' that would appear across those contacts.



To summarise my questions a
Does this sound like a Bipolar TVS?

could be.

If not what is this component and are these blue sparks an indication
of device failure?

don't know.
.....



Many Thanks
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bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

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