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Old 19th Sep 2006, 1:48 pm   #11
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Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Can you give me advice on safety please?

Originally Posted by Brian R Pateman View Post
And use a discharge lead with a 500K series resistor.

If you don't you could do the set some damage. I did this many years ago now and blatted every IC in one of my rental TVs - including the teletext panel!
The resistor is a sensible precaution but shouldn't be needed if you connect the other end of the lead directly to the earthing strap that fixes across the outside of the CRT. Doing it this way ensures that the discharge current doesn't flow through the rest of the set. CRTs sometimes suffer internal flashovers in normal use and the electronics have to be able to survive this. The protective spark gaps and and wiring are designed so that the bulk of the energy from a flashover finds its way back to the outer graphite of the CRT rather than through the electronics.
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