Re: [TCML] CRT wire - harvesting safely

["David Rieben" <drieben@xxxxxxxxxxx>]

Hi all,

Tony Greer wrote:


> Something else to consider it that CRTs are in effect, a Leyden  jar
> capacitor, and can store a potentially hazardous charge for a very long 
> time! Be
> sure to first discharge the CRT by connecting a ground wire to the 
> chassis
> (or the conductive outer coating on the CRT) and then touching it to the
> second anode button on the side of the CRT. Keep it there a while because 
> a
> residual charge will build back up if only touched briefly.

Tony is absolutely correct about this aspect of CRTs and I
can vouch for it from personal experience! About 20 years
ago, I had a 19" color TV that had gone south on me so I
decided to try to salvage the HV "goodies" out of it. I knew
that the flyback assembly could put out around 20 kV but
I did not figure on a significant percentage of that potential
being retained as a static charge on the picture tube itself
after the power was removed, as I tore into the guts of the
defunct television set. When I lifted up the external elec-
troded insulation boot "pasty" on the hihg voltage lead that
connects to the outer wall of the tube and my fingers con-
tacted the bare electrode underneath that was underneath
the boot, I received a very sickening and power jolt of
electricity that nearly knocked me out. OUCH! Haven't
touched any more salvaged CRTs since then w/out first
insuring that they are fully discharged! :^0


> Tony Greer

David Rieben

PS:  I'm glad that it was ONLY a 19" TV and not a 27"
or a 32" set! 

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