Newsgroups: sci.electronics.misc
Subject: Re: RGB TO VGA
References: 
"MadMax"  writes:

> I have an unusual question. Does anyone have any idea how to conver a RGB
> Sync on green output to a VGA Monitor? What I want to do is to setup a
> display for a medical application that uses Hi Res frequencies. The display
> is a fairly good LCD monitor that is multisync. However the input is a
> standard15pin d-sub. The output of the video generator is a 3 cable RGB sync
> on green cable made for a crt monitor. How do I separate the sync off the
> green to feed it into the v and h sync pins of the vga plug. 

For ideas on this check
http://www.hut.fi/Misc/Electronics/faq/vga2rgb/vgamonitor.html

> I tried using a
> LM1881 sync separator but it needs composit video to separate the sync
> pulses. 

The R component in the sync on green RGB signal resembles the 
composite video close enough to be used by ICs that are used  
to separate sync signals from composite video signals. 
Some ICs have limitations on frequencies they support, some 
work to pretty high frequencies well-
For example LM1881 can handle horizonal sync frequencies up to 
150 kHz frequencies if used correctly.

The IC datasheet can be found at http://cache.national.com/ds/LM/LM1881.pdf

> Any help would be appreciated. Please email me if you know of any
> solutions. Thanks in advance.

Hopefully my tips helped you on solving this problem.

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/