projection tv help

[jam92102]

Hi Everyone!  I'm removing my power supply board and I have a question and I figure since arcade monitors are kind of like tv's I might ask your guys suggestions.  There is a (transformer or what looks to be one) on the board with a red wire (either 10 or 8 gauge) running up somewhere up to the 3 tubes.  Is it safe to remove this?  Is there a certain procedure to follow?  I'd appreciate all the help you all could give.  Thanks!!!

[ChadTower]

There shouldn't be three tubes.  There should be three projectors.

[Stingray]

There shouldn't be three tubes.  There should be three projectors.

I soldered a transistor on a friends projection TV a couple months ago. That one looked to have three tubes in it.

-S

[ChadTower]

Three CRTs?

[CCM]

Excerpt from http://electronics.howstuffworks.com/projection-tv3.htm



Transmittive Projectors
Transmittive projectors use two basic image forming elements:

    * CRTs
    * LCDs

Both types are discussed below.

CRT
Like conventional TVs, some projectors have smaller CRT tubes built into them. These tubes are small (perhaps 9-inch diagonal), expensive and extremely bright. In the basic layout, you have one or more CRT tubes that form the images. A lens in front of the CRT magnifies the image and projects it onto the screen. There are three CRT configurations used in CRT projectors:

    * One color CRT tube (red, blue, green phosphors) displays an image with one projection lens.

    * One black-and-white CRT with a rapidly rotating color filter wheel (red, green, blue filters) is placed between the CRT tube and the projection lens. The rapid succession of color images projected onto the screen forms an apparently single color image (the images are projected too quickly for your brain to distinguish between them).

    * Three CRT tubes (red, green, blue) with three lenses project the images. The lenses are aligned so that a single color image appears on the screen.

One of the problems with CRT projectors is that, with anywhere from one to three tubes and accompanying lenses and/or a filter wheel built in, the projectors can be quite heavy and large. Also, CRT devices do not have the fine resolution that LCD devices do, especially when projected.

[ChadTower]

Ohhhh... rainBOWs.

[fredster]

You can always grab it and find out 

[ChadTower]

Oh no, I learned my lesson the LAST time you told me to do that, you perv.

[jam92102]

Oh no, I learned my lesson the LAST time you told me to do that, you perv.

You guys are nuts!   I guess no one knows huh?  Isn't there a similiar setup with arcade monitors?  I was thinking the had a thick wire that connected to the tube as well.

[ChadTower]

Yes, there is, as with TVs and any CRT.  You would have to have a flyback anode (looks like a suction cup but is not) coming from the neck of the CRT and into a transfomer.  This is how the electrons escape the CRT after bouncing off the phosphorescent screen at the front of the tube.  I'm not sure if a projection TV would have three separate flybacks or one big one fed by three anodes.

Either way, though, I'll tell you this, and heed this advice:

KEEP YOUR HANDS OUT OF THERE IF YOU ARE NOT SURE.

[Jess--]

should be three seperate flybacks to allow for different tubes with different emmission levels
its common to only replace a single failed tube rather than all three, then you have 2 dimmer tubes and one full brightness tube.

[ChadTower]

then you have 2 dimmer tubes and one full brightness tube.

Sounds like half the families I know.

[Jess--]

Hmmmm half the families I know have the one dim tube..... the others are just plain OFF