Talk:Cathode-ray tube

Older Comments

since someones mentioned not messing with a CRT, should it be mentioned that one should short the large capacitors to avoid a shock

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I've just added:

These high voltages can persist long after the device containg the CRT has been switched off.

In general, the untrained shouldn't be opening the box in the first place, and providing warnings is better than providing "how-to" details: where do you stop?

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To do:

• phosphor metamerism
• color gamut

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The line "CRT is a triode. More complex CRTs contain greater numbers of electrodes. " was deleted. Primarily, this makes no sense logically, and also, triodes were mentioned later.

Sounds good to me, welcome to Wikipedia. -- Tim Starling 07:47, Jan 5, 2004 (UTC)

CRT illustrations made especially for Wikipedia

Hi - danish wikipedian here.
For some snazzy illustrations, check out the danish article (language: "Dansk") on the subject: I just rendered some "cut-away" images of various CRTs...

User:Peo on danish Wikipedia

... and now I've moved large versions of those illustrations onto Commons. See:

• http://commons.wikimedia.org/wiki/Image:CRT_color.png
• http://commons.wikimedia.org/wiki/Image:CRT_monochrome.png
• http://commons.wikimedia.org/wiki/Image:CRT_oscilloscope.png

User:Peo, from danish Wikipedia - again!

How many joules are in the capacitors? lysdexia 22:18, 19 Oct 2004 (UTC)

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"...children should even be encouraged to do this so that they may see the immediate and dramatic effect of a magnetic field on moving charged particles, provided they are informed to never do the same with a color tube."

TEACHER: So remember, kids, never put a magnet near your TV or you'll mess up the screen.

JOHNNY (THINKS): Gee, that's great! If I mess up our crappy old TV Dad'll have to get a new one! Lee M 01:59, 2 Dec 2004 (UTC)

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I wonder if *THAT* is what happened to my crappy old 13" TV? :)

Seriously, the Exploratorium has a color TV and a huge magnet set up for just this sort of playing around.

Meanwhile, [[User::lysdexia]] asks about how many joules are stored. Well, Joules = KV^2 * uF, so lets take a SWAG and call the CRT 0.01 uF. Meanwhile, the charge on the CRT can be 25 to 30 KV on a modern color CRT so we can calculate 6.25 to 9.00 Joules based on our SWAG about the capacitance. Having been on the receiving end of a 17KV discharge from an old B/W CRT (never grab the 1B3GT by the bottom; you might contact the HT pins!), I say that sounds like it's in the right ballpark. The shock wasn't too bad, but I really hurt my elbow when it smashed into the wall behind the TV set.

Atlant

Explanation of the Colour Spectrum of CRTs

I'm trying to find out why the blue and green phosphors emit a broad spectrum while the red emits a much 'spikier' / well defined set of peaks (File:CRT phosphors.png), but as far as I've read I can't see anywhere in the article it mentions the reasons behind the spectra of the phosphors. Anyone know? NotAMaestro (talk) 11:24, 31 January 2023 (UTC)

"(CRT)" listed at Redirects for discussion

The redirect (CRT) has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2023 August 31 § (CRT) until a consensus is reached. Skynxnex (talk) 04:19, 31 August 2023 (UTC)

Additional environmental content

I've removed the content below from Digital television as CRT to flat-panel transition is separable from the transition from analog to digital transmission. I'll try to return and work this material into Cathode-ray tube § Health concerns and Cathode-ray tube § Recycling but if anyone else wants to take this on before I get to it, have at it! ~Kvng (talk) 16:26, 16 March 2024 (UTC)

According to one campaign group, a CRT computer monitor or TV contains an average of 8 pounds (3.6 kg) of lead. According to another source, the lead in glass of a CRT varies from 1.08 lb to 11.28 lb, depending on screen size and type, but the lead is in the form of "stable and immobile" lead oxide mixed into the glass. It is claimed that the lead can have long-term negative effects on the environment if dumped as landfill. However, the glass envelope can be recycled at suitably equipped facilities. Other portions of the receiver may be subject to disposal as hazardous material.

Local restrictions on disposal of these materials vary widely; in some cases second-hand stores have refused to accept working color television receivers for resale due to the increasing costs of disposing of unsold TVs. Those thrift stores which are still accepting donated TVs have reported significant increases in good-condition working used television receivers abandoned by viewers who often expect them not to work after digital transition.

References