Hey /diy/, I've got a caseless 5 inch CRT. Do I need to worry about the tube itself building up a dangerous charge, or is the flyback the only dangerous part?
pic isn't mine
Neither.... i have dismantled tons of crt and nevur got a shocks
The CRT itself does not hold a charge, the flyback's internal capacitor does. The only way you'll manage a housefire with that would be to have a spark gap between the primary and ground of the flyback looped directly on each side of something flammable, ie, you want it to light something on fire. If you use it like it's supposed to be, everything will be fine. If you want to touch it but you're not sure if it's safe, use one hand only.
No, don't thank him, he's wrong, and you're a fucking idiot for coming to 4CHAN of all fucking places, instead of running a damn google search. I should have let you cop a few kilovolts off the tube as a lesson, but I'm not a cunt like >>932161 is.
The internet. Use it faggot.
Nah, he's charging it up, switching it off, sparking it, then charging it up again.
The electrons fly from the gun to the screen because of the potential difference; they couldn't do that if the screen wasn't a capacitor.
That said, it is just static. It's more dangerous than a fieldmouse, but less dangerous than a chainsaw.
>Do I need to worry about the tube itself building up a dangerous charge, or is the flyback the only dangerous part?
This >>932161 faggots response.
> The CRT itself does not hold a charge
This >>932525 guys response.
> The CRT does in fact hold a charge, here's a video of how to discharge it.
You are an illiterate faggot who cannot follow a conversation, and does not know enough about electronics to recognise what this video demonstrates. Please leave this board and never return.
It shouldn't be. The anode cap and its connection back to the flyback transformer are well insulated, so there is very little risk of copping a shock through the cap or the flyback insulation. Personally, unless I need to pull the circuit board out of the unit for bench testing (reads; need to disconnect the anode cap) I won't bother discharging the tube. The danger is always in the back of my mind, complacency can be a killer, but yeah, it's not something you need to do everytime you want to do work.
If you are in any way concerned, the discharge video >>932525 posted is a quick and easy way to give yourself piece of mind. I would also recommend you go have a read up on how the high voltage section of a TV works, and the role aquadag plays in CRT voltage management. Arm yourself with the knowledge to work safely and confidently around HV devices like these, You'll get more done and more importantly, you won't get fucked over because some psychopathic fleshwaste on 4chan thinks it's fun to kill by proxy.
To be clear, you're looking to run this CRT without an enclosure (or maybe put it in your own custom enclosure), correct?
>To be clear, you're looking to run this CRT without an enclosure (or maybe put it in your own custom enclosure), correct?
Yes, that's right. I was expecting to have to put the flyback transformer in some sort of enclosure, but the tube itself I'd like to leave exposed.
I'm reading about aquadag now, thanks for pointing me.
Am I right in saying that if it's not connected to anything, and it builds up a charge (which it can do), there's no reason to expect the exposed grounding posts should be at ground potential?
Whenever I've had to store these things, I've fashioned an anode-cap clip out of a bulldog clip handle and a wire, and used that to short it to the grounding posts.
>The tube ITSELF is a big capacitor
Right, but the outside of it is only one terminal, right? You can only shock yourself by touching the flyback at the same time, or by reaching under the anode cap.
Yeah, the graphite coating alone, which is normally grounded and also the other terminal of the capacitor formed by the CRT. The other terminal is the anode contact.
What's so difficult to understand?
Sweet jesus, someone just tell him how to discharge it instead of debating on if or if not it'll have charge. Ground a long flat screwdriver using wire to something you know is grounded. Use the flat screw driver to to pop off the suction cup of the fly. Touch the opening that the fly attaches to and the metal clips on the fly cup itself. You won't have to worry about anything after that. And YES tubes will collect static over time and recharge. Discharge the tube and fly if you ever worry about shocks. I've known many a tech that have gotten slammed into a wall from bad shock reactions
That was a cheap shot, and they absolutely do.
>Yeah, [you were touching] the graphite coating alone, which is normally grounded [;] [the graphite coating is] also the other terminal of the capacitor formed by the CRT.
Personally I'd be a bit wary of doing that, because CRTs often have strange ideas about what potential the chassis should be at, and touching the "ground" on a CRT while it's on can be way more dangerous than getting a boo-boo off the HV, but whatevs.
I wish either one of you would talk to me about the specifics this particular TV. I touch the ADAG no issue- is there another place (ON THE OUTSIDE) I might accidentally touch and die/start a fire?