VGA -> RGB adapters

[xjas]

These are all over Ebay for peanuts. I bought all the components to make my own but then realized I don't have a roll of solder. Then I saw these for about a third of what I spent, with free shipping. Yeah.

Does anyone have one? What do they do with the sync signal (physical VGA pins 13 & 14?) Does the VGA card have to support outputting sync-on-green or something, or are the standard sync pins tied in, and to which colors?

 

[vwestlife]

The photo in this one shows that's a component video (YPbPr) to "VGA" adapter -- and the term VGA is used loosely because the device must be designed to accept component video through the VGA input:

http://www.ebay.com/itm/271995586841

The reference to "RGB" is probably just a reference to the fact that component video uses red, green, and blue RCA plugs, even though it is not RGB video.

 

[xjas]

Is that how you're supposed to use them? That kind routing kind of makes my brain hurt. :headslap:

I was hoping for an easy solution to replicate this circuit because I *really* hate soldering onto HD15 connectors, especially with my crappy iron. If I can buy one for $2.50 instead of DIY in this case I totally would. (I might anyway and just see what it does but ~2 week shipping time is annoying.)

                       1K ohm 
                   +---/\/\/------------------+
                   |   1K ohm                 |
                   +---/\/\/---------------+  |
                   |   1K ohm              |  |
        Hsync o----+---/\/\/------------+  |  |
                                        |  |  |
                       1K ohm           |  |  |
        Vsync o----+---/\/\/------------+  |  |
                   |   1K ohm           |  |  |
                   +---/\/\/------------)--+  |
                   |   1K ohm           |  |  |
                   +---/\/\/------------)--)--+
                                        |  |  |
                       100 ohm          |  |  |
      VGA red o--------/\/\/------------+--)--)-------o Composite Video In 1
                       100 ohm             |  |
    VGA green o--------/\/\/---------------+--)-------o Composite Video In 2
                       100 ohm                |
     VGA blue o--------/\/\/------------------+-------o Composite Video In 3


      Red Gnd o----------------------------------------o Composite Gnd 1
    Green Gnd o----------------------------------------o Composite Gnd 2
     Blue Gnd o----------------------------------------o Composite Gnd 3

 

[KC9UDX]

I wish I could understand why you would want to do that.

 

[xjas]

Break a VGA signal into three separate RGB channels (technically 3 monochrome channels) with composite sync? Why wouldn't I want to do that?

 

[KC9UDX]

So you're going to have three display monitors: one for the red signal, but displaying white (or whatever colour phosphor you have), one for the green signal, but same, one for the blue signal, but same.

Why would you do that?

 

[Stone]

Why would you do that?

Strap yourself in for this answer!

 

[njroadfan]

They make VGA to 5xBNC (R,G,B,H sync, V sync) cables exactly for that purpose. If you need composite sync or sync-on-green, there are combiner circuits out there.

 

[xjas]

Well, I got un-lazy, found my roll of solder, and made my own. Fortunately I was able to scavenge some pre-soldered HD15 connectors w/ribbon cables off a couple old slimline Radeons so I didn't have to do *that* part myself.

Why would you do that?

Strap yourself in for this answer!

The short answer is "art project." The long answer ....... will be posted here when it's done, rest assured.